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Chord Electronics Blu Mk2 upsampling CD transport

The Chord Blu Mk2 is a recent addition to the Chord family, and a sister for DAVE – the ground-breaking DAC designed by Rob Watts. A conventional CD transport, together with the ability to upscale CD to 768kHz, makes this a natural upgrade for the DAVE, taking its ability to utilise its 164,000 taps in the Watts Time-Aligned Filter to over a million!

The Blu Mk2 comes in an aluminium case which is of similar dimensions to the DAVE. It has digital inputs for USB up to 768K, a BNC S/PDIF input, and outputs comprising a single AES/EBU, a Dual AES/EBU, and the similar configuration for S/PDIF outputs. Conventional CD buttons provide the usual functions, which can also be accessed by the supplied remote control.

There are two small switches on the back; ‘Dither,’ which only works with a 16 bit output, and a toggle which gives three levels of upscaling. The CD is inserted by flipping a metallic cover back, and dropping the CD into the playing space. Getting it out is more of a procedure. There is a modest insert in the CD surround below to insert your finger in order to remove the CD. Not the easiest procedure for someone with fat fingers, and difficult to do without coming into contact with the playing surface of the disk. It’s not the most gloriously beautiful way to load and unload a CD, but I suspect that not having a drawer may save trips to the repair shop in twenty years time! The internal mechanism is the Philips CD Pro 2 Mech favoured by many manufacturers, and known for its reliability.

Upsampling aside, it’s a CD transport, so its operation and installation are well known to all. The only real caveat to that is to get the full benefit of that upsamping between Blu Mk2 and DAVE, you need to connect using a dual BNC arrangement, and there’s an unofficial (though Rob Watts approved) idea of slipping ferrite beads over these cables at the Blu Mk 2 end for maximum performance.

 

Listening to an old favourite CD of mine, Haydn Symphony No 77, Christopher Hogwood and the Academy of Ancient Music, the difference between the three oversampling/upscaling options is not small. Starting with the minimum oversampling rate, which reads as 88.2 kHz on the DAVE, I get a pleasant presentation, fluid and coherent, but not the deepest of soundstages. Changing to the maximum oversampling immediately improves imaging and increases soundstage depth, while creating much greater space between the instruments in the orchestra. It’s almost as if you have pressed a button marked ‘3D’. There is also a sense of what happens when you move back five rows in a concert hall, a hint of the concentration of the intensity and colour of the sound being slightly diluted. On this period instrument recording, I miss a bit of weight in the bass; it is true that period cellos and basses make less grunt than the modern equivalents, but it is noticeable nonetheless. Contrasting the Blu with my Esoteric K-05 CD player, used as a transport only, playing through the DAVE via a Chord cable, the latter seems to have more grunt and there is more of a sense of the bass driving the harmony and the music than with the Blu Mk2. It doesn’t, however, have the effortless sense of space that the Blu Mk2 has, or indeed the litheness of its approach to making music.

Next I moved on to an astounding recording made in 1959 – Von Suppé Overtures, and in particular ‘Pique Dame’ by the Detroit Symphony Orchestra under Paul Parry [Living Presence]. This was recorded with just three microphones, and that shows up some really interesting things. On this most organically recorded of discs, upsampling seems to extract every last detail of the orchestral image beautifully. It is as close to a purist ideal as you can get (I suppose the engineer could have used only two mic’s!). Compared with my Esoteric feeding the DAVE directly, I can hear the amazing separation and phase information on the Blu Mk2 being extracted by the upsampling, and it is highly impressive. Interestingly, where the kettle drum sounds a bit loose and flabby with the direct version, the upsampled Blu Mk2version reduces its role, but makes it tighter and better controlled. The moment of impact of the stick to the drum skin is better defined. The Blu Mk2/DAVE combination really does make greater sense of this recording.

On to the Grieg Concerto, a vintage Philips recording, Stephen Bishop with Colin Davis. It is fascinating to see how this rather magical recording, which through the Esoteric and DAVE sounds good, but old! It’s on the tubby side, an old-fashioned with slightly congested sound. Through the Blu Mk2there is a radical transformation: the piano sounds less muffled, more incisive, more lyrical, and less lard-like; the orchestra (which doesn’t have a detailed presence) suddenly appears like it’s been snapped by a camera with a lens that has just been cleaned. Again a little less bass, but it sounds like a recording from several decades later. The piano sounds most different, because the start of each note has greater clarity, so that the tone sounds very different and much more lifelike. More Steinway, less Bösendorfer!

Turning to some rock music, I tried Madonna’s Ray of Light album [Warner], and the Frozensoundtrack [Disney].  As previously with the Blu Mk2 on maximum oversampling the components in this electronic and acoustic mix are blown backwards and expanded detail-wise, the top end is sweetened (that is, made less shrill), but some of the drama of the track is sacrificed for this cause. The bass is slightly less present, it seems as before not to be driving the music but playing with it. the Blu Mk2 makes real sense of the violin section, instead of a bland blancmange texture, heard raw through the DAVE, I’m aware of a mass of violins, and their weight. There is more of a sense of how the mix is stuck together: The drums have a different acoustic to the singer and the orchestra, and you can sense the booth in which the drums were recorded.

There seems to be a common thread. Upsampling carries with it certain positives, as well as the occasional less-than-positive. It really is almost like a complex DSP function, which alters the sound in a way that may be very useful, depending on the characteristics of your system. For music, or a system that has a tendency to be too forward, the upsampling tendency to push the performance back a few rows is a positive thing, as is of course the increase in space, and accuracy of the imagery yielded. The quality of the bass seems to improve, and there is a more accurate beginning to notes, which is particularly evident when pianos and drums are involved. The quantity of the bass is lightened in the process, which could help certain systems, but could also hinder in the case of rock music.

 

The Blu Mk2is a fine transport which opens many possibilities of sonic changes and developments in a system, and when partnered with the DAVE, shows the possibilities of upsampling done well.

TECHNICAL SPECIFICATIONS

Chord Blu Mk2 

  • CD Resolution: 44.1kHz–705.6kHz (user configurable)
  • Connectivity (input): 1×USB input: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz, 384kHz, 705.6kHz, & 768kHz
  • 1×BNC S/PDIF: 44.1kHz–384kHz (upsampled)
  • Connectivity (output):
    1×Single AES Option: 44.1kHz & 88.2kHz
    1×Dual AES Option: 88.2kHz & 176.4kHz, 1×Single BNC S/PDIF Mode: 88.2kHz, 176kHz, & 352.8kHz, 1×Dual BNC S/PDIF Mode: 176.4kHz, 352.8kHz, & 705.6kHz
  • Selectable upsampling: 1×selectable switch providing three sample rates (44.1kHz, 176.4kHz, 705.6kHz)
  • Dither: On/Off (only operational with 16bit source)

Price: £7,995

Manufactured by: Chord Electronics

URL: chordelectronics.co.uk

Tel: +44(0)1622 721444

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Read more Chord Electronics reviews here

CH Precision I1 integrated amplifier

Let’s talk terms, and their inappropriateness at times. The I1 by Swiss electronics superstar CH Precision is – by the standard definitions of our industry – an integrated amplifier. To define a product as flexible and as powerful (in several senses) as the I1 in this way is like defining a surface-to-air missile as a ‘firework’. The more accurate definition of the I1 would be something closer to ‘a modular audio platform utilising a wealth of different daughter boards for operational optimisation plugged into a custom motherboard that includes an on-board amplifier component for high-performance single-box audio use.’ OK, maybe ‘integrated amplifier’ rolls off the tongue a little easier.

CH Precision uses the same chassis and design for its source components, preamplifiers, power supplies, and the one-case-does-all integrated I1. They all have the dual-dial single control, the distinctive left-hand panel curve and the magnetised-to-the-side remote handset. In fact, you can only tell them apart from the rear panel configuration and the subtle logo on the front screen. Otherwise they are functionally identical to one another, and even weight is no useful indicator, as they all fall into the ‘substantial’ class. This makes for a very consistent equipment stand if you start stacking them atop one another: in fact, the CH Precision devices all have removable threaded rod-like feet running through the four corners of the device, which could allow for stacking… though at least one pundit thinks make the CH Precision amps sound better when they are removed.

The I1 platform (I still can’t bring myself to thinking of it as an integrated amp) is best described by its rear panel. The basic layout has a set of large Argento speaker terminals at the extreme left and right of the panel, a central panel with IEC power inlet, switch, and fuse, a digital input HD board with AES/EBU, S/PDIF, Toslink and CH-Link HD for connection to CD Precision’s D1 CD/SACD digital front-end, and an analogue line input with RCA and XLR inputs. The rest in this basic guise is all a series of blanking plates. Additional modules include a USB Class 1.0 and 2.0 streaming input board, an Ethernet streaming input, and a current-mode MC phono input, itself with a full spread of EQ curves and also a Sync I/O board that allows the I1 to be enslaved to an external clock such as CH Precision’s T1 Time Reference using a coaxial cable. All connected to a motherboard layout with 2x 100W power amp stage. We went with a model that included all the options.

Depending on input, the platform operates in the digital domain at 384kHz/352.8kHz from input to that Class A driver with Class B follower power amp stage, complete with CH’s own ExactBias biasing system. This is not like most integrated amplifiers, but more akin to a Vitus design – a power amplifier with benefits! The amplifier itself features a fully shielded 1kVA power transformer and has something in the region of 100,000µF of reservoir capacitance on tap. And yet, thanks to some extremely high-grade diodes in the bridge rectifier stage, it sounds deceptively fast like a small integrated design.

The modules are key to the story, though. It’s best to think of each one as a small version of some of CH Precision’s separate components (because actually that’s what they are). So, the digital input board works to 24bit, 192kHz/DSD64 precision on its standard inputs, or up to 32bit, 768kHz/DSD128 on the CH Link that you would use with a CH Precision D1 disc transport. The MC board allows up to two different turntable inputs (balanced or single-ended) and can cope with any load the right side of 100mΩ, with adjustable gain. And so on, all fed through a volume control that moves in precise 0.5dB steps from -100dB to +18dB.

The only real problem with all of this is describing it without making it sound bewildering. But it’s like a bespoke suit; it’s effectively made for you, and once complete fits you perfectly for longer than anything ‘off-the-peg’. Its flexibility is not a weakness or a sign of indecision on the part of the manufacturer; it’s a conscious programme to make sure you have an amplifier designed specifically for you.

An interesting aside is the connectivity of the streamer board. Unlike most on-board devices in this category, there is no provision for wireless connectivity as standard. Instead, the Ethernet connection is designed to attach to a wireless router (maybe via a network switch), with devices like a NAS drive also hanging off that external network. This is, I feel, a better way of isolating the potential ingress of radio frequency interference, especially if you use acordon sanitaireof some description between network and audio systems. Of course, this means less of an ad hoc approach to networking, which goes some way against the ‘Plug ‘n’ Play’ notions held by many companies, but if you are going to do a job, do it properly.

 

To this end, CH has also chosen to go down the Android route in its app design. There are good reasons for this, but I can’t help but feel this laudable one-sided approach will disenfranchise some who are seemingly wedded to Apple’s products. There are people who simply don’t ‘get’ Android, many of whom are in the target demographic for a very high-end device like the I1, and having that option denied them might make them skip over what is an excellent device at the short-list stage. I would hope that is not the case and those reading this review would rather explore the world beyond the iDevice in order to sample the many joys of the CH Precision I1, than simply turn the page, but human nature is what it is!

The app itself is extremely stable and robust. Like all such systems, there is a learning curve, but it’s more ‘gentle sweeping curve’ than ‘sheer cliff-face’ and you quickly come to a point where it is intuitive in use. Like Linn’s Kinsky app, it’s more about creating on-the-fly playlists than instant playing gratification, but I find myself preferring this option more and more. The CH app’s great advantage is it can control almost every aspect of the I1 in use, from input settings to naming: although this can be performed on the knob-within-a-knob front panel selector, things get a lot easier from the comfort of a chair. It’s other great advantage is it scans through music about as fast as the device to which it is connected: we used it with a Melco N1Z streaming storage server system (with built-in alliteration control!) which is itself one of the fastest moving digital devices around, and the CH Control app positively whipped through the back-catalogue.

It’s also worth mentioning the front panel interface. Or rather the excellent front panel display with the occasionally frustrating twin dial combined volume control, source selector, menu access and controller. This is excellent as it makes an extremely clear and large display or the I1’s status. This is frustrating because the two concentric dials take some time to master and in the early stages might result in some random swearing as you end up locked in a sub-menu. On balance, I’d prefer this to a panel festooned in tiny buttons that might get used once in a decade.

Because they have distribution links in many places, the CH Precision I1 is an obvious partner with Wilson Benesch loudspeakers, but it also got an airing with a number of loudspeakers and the character of the amplifier shines through throughout.

I want to look to this amplifier without calling upon CH Precision’s bigger hitters in the amp stakes; specifically the A1 power amplifier we tested in issue 120 and the L1 preamp and M1 mono amp combination we tested more recently in issue 159. But I can’t; much of what makes these outstanding amplifiers sound so good also applies to the I1; not so much ‘trickle down’ as ‘rushes down in a torrent’. So many of the properties of CH Precision’s separates amplifiers make it to the I1, it almost makes you question whether the bigger options are worth the extra. And like all top-notch audio brands, that voice is heard right up until you hear the big guns, and it then falls silent.

The same core sound of ‘impressive understatement’ remains uppermost. The amplifier is not the kind that draws attention to itself and doesn’t even draw attention to the sound it makes; there is just a gradual dawning that you are listening to something really natural and well-designed. It’s more a drawn-out ‘aha!’ than an ‘eureka!’ in listening: a slow and gradual seduction that becomes increasingly impossible to resist.

You also begin to discover (pretty soon into the listening, in fact) that the ‘Precision’ part of the name ‘CH Precision’ isn’t just there for show. It is an extremely precise and accurate performer. Music played here is tautly controlled, yet with more than enough dynamic punch and energy. Although this is the kind of presentation that lends itself to torch song singers and 1950s jazz, the CH Precision I1 is so good at portraying these well-recorded works that it makes it almost academic in discussing them at length. Far better to point to something with more textures and layers, like The Race for Spaceby Public Service Broadcasting [Test Card]. This clever slice of ambient music blends samples of speech from the 1960s with an almost Mogwai-like aesthetic. It can either sound like boring chill-out music or make you want to join Trump’s Space Force, and here that precision and dynamism made me reach for my space helmet! Flipping through the different sources from different card inputs also made clear another aspect of the ‘Precision’ part of the name: consistency. There was no functional tonal change as you moved through the inputs, whether analogue or digital. This is not something you normally notice, but once heard, you become aware of its absence in other devices. If accuracy is king, then consistency is the power behind the throne.

In a way, the CH Precision sound is inherently Swiss (hardly surprising; apparently the people from CH Precision, Nagra, and Soulution are all pretty tight with one another) and the CH Precision sits comfortably in the centre of that firmament. They seem to be on a continuum from the delightful and slightly lush-sounding Nagra to the detailed and almost surgical precision of the Soulution. CH Precision finds a middle way, one that keeps music as attractive as possible, yet also keeps it precise, detailed, and accurate. It’s a bit of a high-wire act, and the CH Precision walks it perfectly.

The criticisms of the I1 hold even after listening. It’s a necessarily complex device (in terms of selection criteria and installation) that is best used with an Android tablet. And, let’s not shy away from it… in its full specification the I1 is one of the most expensive integrated amplifiers on the market right now. While it more than justifies its place (and its price) in that highest of high-end firmaments, those with pre-gnashed teeth will play judge, jury, and executioner without ever having listened to it on the basis of price alone.

 

Those suitably well-heeled to consider the CH Precision I1 without the price tag being an issue are also well equipped to assess its performance in a more level-headed manner, and they will come away extremely taken by the I1. It’s an amplifier of rare grace and musical elegance, yet with a drive, dynamism, and force not normally associated with terms like ‘grace’. That makes for a beguiling combination of performance parameters, and ones that don’t get forgotten quickly.

The CH Precision I1 has a tough job to do. It needs to be awesome enough to justify its price and position both in the CH Precision line-up and against the rarified air of some of the best ever integrated amplifiers in the price-no-object class. But it also has to be good enough to showcase what the bigger fish in the CH Precision pond are capable of, but not so good as to outshine those bigger fish. Of these tasks, only the last is a realistic goal, because the separates CH Precision components are an order of magnitude better than both the I1 and any of its rivals. But the I1 does all the other tasks, too. This is one of the best integrated amplifiers (and I still hate that term for this design) you can buy.

TECHNICAL SPECIFICATIONS

  • Type: modular integrated amplifier
  • Inputs (as standard): 1×AES/EBU, 1×BNC S/PDIF, 1× Toslink, 1×CH link
  • Inputs (optional): XLR balanced and RCA single-ended inputs, MC phono input (analogue) RJ45 Ethernet, USB Audio Class 1.0 and 2.0 (digital)
  • Power output: 2×100W RMS (8Ω), 2×175 W RMS (4Ω), Adjustable feedback levels
  • Amplifier Class: Pure Class A driver with Class AB follower
  • Volume control: 118dB range in 0.5dB steps
  • Digital audio precision: up to 34-bit, 768kHz and native DSD to 5.6448MHz/1=bit
  • Display: 480 ×272pixel, 24bit RGB AMOLED
  • Dimensions (W×H×D): 44 ×13.3 ×44cm
  • Weight: 43kg
  • Price: £29,500 (as tested)

Manufactured by: CH Precision

URL: ch-precision.com

Distributed in the UK by: Wilson Benesch

URL: ch-precision-hifi.co.uk

Tel: +44(0)114 285 2656

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Read more CH Precision reviews here

Sneak Peek: Hi-Fi+ Awards – Accessory of the Year

Although Critical Mass Systems is best known for its large and heavy rack systems, perhaps its most important product is the CenterStage2, a range of three equipment support feet designed to correct physical impedance mismatching to greatly reduce vibration moving upward from the floor, the reduction of the noise inherent to the materials used to fabricate the foot, and a means to transfer entropy out of the component. To these ends, each CenterStage2footer represents an ideal combination of damping, elastic modulus, and thin rod speed. The three models are designed to accommodate different sizes and weights of components, although there is a good/better/best performance aspect, too.

The curious thing about the CenterStage2is that you know when its working because it makes the system sound a lot worse, at first. Until the footers harmonise and begin to correct those impedance mismatches and beyond, the sound of the system goes thin, light, bright, and the soundstage and dynamic range all but collapse. Then, as it begins to settle, the sound undergoes a quick and significant change for the better, and it keeps getting a lot better. We felt that “You notice this change by a shift in your internal dialogue. ‘I’d forgotten just how good that really is!’ (referring to both record and equipment) seems to be the first sign. About an hour later, you find yourself composing a thank-you email to the designers of the components in your system. Although it’s the bass that first comes back, it’s the midrange that seals the deal: the enhanced clarity, the walk-in detail to the soundstage, which seems to not change a thing, all the while being far more enveloping than before. This is no small change, and as the listening progresses, you begin to find this feeling of being immersed in the music.”

Reviewed in Issue 163

Gold Note PA -1175 Mk2: MORE IS MORE

FLORENCE,Italy: Gold Note – the Italian High-EndAudio manufacturer based in Florence – is introducing PA-1175 Mk2,the updated

Power Amplifier designed to enhance your stereo system even better.

Here is the revised version of Gold Note’s first stereo amplifier, which replaced the awarded Demidoff Anniversary amplifier in 2015. Our latest creation, again, features all the innovations that have always distinguished our designs: PA-1175 MkII merges the latest innovations with the knowledge of over 20 years in designing electronics to create an even more powerful, detailed and smooth Power Amplifier.

PA-1175 is a Stereo Power Amplifier which features 4 matched pairs of transistors per channel with a proprietary Gold Note BIAS constant current generator which enables high currents and high power rates with ultra low distortion.

The power amplifier features a BTLtechnology [Bridge-Tied-Load] so the unit can be easily bridged to work as a mono amp doubling its large power rate from now 200watt (previously 175watt in the Mk1) per channel @ 8ohm up to a considerable 520watt (previously 350watt) per channel.

The flexibility of the power amplifier can be largely extended with the mono application for all kind of speakers that really require high power and massive energy.The latter is provided by a 640VAcustom made toroidal audio transformer with original Ducati race bike silent blocks to guarantee a terrific effect and perfect insulation.

A small 6VA transformer powers all service functions outside the audio signal path to preserve the best performance exceeding 1000VA peak if the power demand of current requires it.

PA-1175 also features a Damping Factor switch conveniently selectable from the front panel. Set up to 250 DF or 25 DF it allows an ideal match with any kind of speakers. At 250 DF it guarantees greatest control necessary for large and difficult speakers while at 25 DF acts as a low power tube amplifier,ideal to drive high-sensitivity or mini monitor speakers which would not perform well with big amplifiers.

 

Top-level electronic components combined with real balanced design with RCA, XLR complete the PA-1175 premium quality design. PA-1175 is built around a high mass steel chassis and thick aluminum panels to avoid RFI and EMI interferences at the same time.

The design derives from the Gold Note 1000 series and uniforming the entire Gold Note premium line of Hi-Fi electronics. The aluminium panels are made of brushed aluminium available in black, silver or gold finish. The increase in power, the new wiring and the replacement of some key components such as the power devices have made this amplifier able to drive any type of speaker with maximum musicality and make the new PA-1175 MkII the best amplifier ever made by Gold Note.

From the beginning of December 2018,PA-1175 MkII will be available worldwide through Gold Note dealers at a MSRP of 5.500€.

 

Technical Specifications

Power Amplifier with optical BIAS

Dimensions: 430mm W | 135mm H | 370mm D

Weight: 22 kg

Power Output: 200W per channel @ 8Ω and 520W @ 8Ω in mono BTL

Frequency response: 1Hz-100kHz at +/-1dB

THD – Total Harmonic Distortion: <0.01%THD @ 20Hz-20kHz

Signal to Noise ratio: -110dB

Damping factor: Selectable 250 or 25

Slew rate: 20V/μs

Audio Inputs

Stereo RCA, stereo XLR balanced

Input sensitivity: 1000mV on RCA and 4000mV on XLR

Input impedance: 47 Kohm

Audio Outputs

Speakers: Gold Note BP-01 Rhodium Plated Binding Posts

Power Section

Main supply: 100 to 245V, 50/60Hz, depending on market destination not convertible

Power transformers: 640VA Toroidal Customized Audio Power Transformer and 6VA transformer for all service out of the audio

signal path

Power consumption: 1200W max – <1.2W idle

About Gold Note

Gold Note (www.goldnote.it) has become one of the leading Italian manufacturers in the Hi-End audio, now with more than 20

years of experience in engineering and designing a complete line of analog equipment, electronics and loudspeakers. Founded

in Firenze, Italy, where every product is still hand-built from scratch with high-quality materials, its creations are a statement of

Italian craftsmanship and innovation appreciated in more than 25 countries worldwide.

Company Contact

Akamai s.r.l.

Address: Via della Gora, 6 Montespertoli (Firenze) Italy 50025

Phone number: +39 0571 675005

E-mail: [email protected]

www.goldnote.it

Sennheiser HD 820 circumaural closed back headphone

Sennheiser’s HD 800 series is ever-expanding. It began with the original HD 800 almost a decade ago. That model is still on sale, but a few years ago, the company launched an HD 800 S model with a more subtle and softer top-end, in part seen as addressing concerns of many prospective HD 800 owners. But then came the HD 820.

The HD 820 is the closed-back variant of the HD 800 Series. High-end, closed-back circumaural dynamic headphones are relatively rare, primarily because they are very difficult to manufacture without sacrificing performance in the process. Sennheiser decided to it was worth the effort, however, and the HD 820 was born.

Closed-back dynamic headphones are extremely popular in the professional world. Studios, field recordists, video production, and electronic news gathering teams use them exclusively to monitor sound, because any kind of open-backed design would leak sound into the recording itself. Nevertheless, this creates its own price ceiling (Sennheiser’s own HD 25 series are a popular choice among the field recorder and video production set, because they are small, light, rugged… and cost about one-eighth the price of a pair of HD 820’s).

Sennheiser set itself a bold challenge; to make a headphone as good as the HD 800/800 S, in a closed back design. That meant using the ring-radiator drive unit developed for those models, and that posed a real problem for the company; it’s one of the most uncoloured transducers in audio because it is so open. If you look to the ear-cup of an HD 800 or HD 800 S, it’s effectively an open basket to hold the drive unit. That means the HD 800 and HD 800 S leak sound like a very leaky thing that just got used for target practice by six guys with shotguns.

Sennheiser’s answer: glass. The HD 820 has a concave glass cover on either earcup encasing the main part of the diaphragm, so no back radiation can spill out into the real world. Perhaps surprisingly, glass is the main way of stopping the leak of the HD 800 and HD 800 S. Equally surprisingly… it works!

Of course, changing the system from open to closed back does require some extensive redesign and testing, if for no other reason than the addition of a piece of glass to seal the case completely changes the pressure loading of the diaphragm (the older models expect to see a free space rear excursion, and by simply covering that diaphragm with your hand, you can hear how the pressure changes from you cupping the driver alters the sound. That means quite extensive changes to the internal layout, although the exact nature of the changes is not disclosed by Sennheiser.

 

Perhaps even more than the HD 800 and HD 800 S, the HD 820 demands a good DAC/amp to deliver the sonic goods. And with the HDV 820 (which we tested alongside the HD 800 S in issue 157) Sennheiser has just that: a refined, yet powerful headphone amplifier with built-in DAC designed specifically for the HD 800 range.

The HD 820 took longer than its stable-mates to run in, but in fairness, the model I received was new in the box and others had been around the block a few times before they came to me. But either way, we aren’t talking months of running in to get everything ship-shape, and it sounds pretty good out of the box, and fantastic a week or so later.

The HDV 820 is why the HD 820 comes with a specially tuned symmetrical, impedance-matching cable with low capacitance and a balanced 4.4 mm gold plug. It’s geared for demanding home use, not drowning out the sound of commuters. For that, you have the HD-25 and it’s more-than-pro following.

There are in effect two related tests here. Does the HD 820 really achieve the goal of putting the HD 800 in a closed-back design, and if it doesn’t how close does the sound get? If the apple falls far from the tree, is it an 800 in name only?

Fortunately, I didn’t get that far down the musing alley, because the HD 820 is very much a part of the HD 800 family. Tonally, it’s closer to the HD 800 S; a richer, more alluring sound, without too much over-enthusiastic energy. But, in almost every way it achieves the near-impossible: open-backed sound from a closed-back headphone design. The test of this is a close-knit string quartet, such as the Takács Quartet playing Beethoven’s later quartets [Decca]. Those who think string quartets are genteel affairs are wise not to follow my lead and buy these discs, because they are anything but genteel. But a good pair of open-backed headphones will project the sound out into the seeming real world, where a pair of closed-backs place the musicians more inside your head. In the case of the HD 820 though, those musicians are out in the open.

There is a freedom and, well, openness to the sound of the HD 820 that belies its closed-back standing. It doesn’t force a lateralisation of the sound like many closed-back models and instead just sounds more like an open design.

Is that open-backed design really an HD 800? Mostly, yes. It’s got that extraordinary detail level that all three models in the range do so well. It’s got that honest-to-a-fault transparency, and in terms of dynamic range, if anything it outshines the previous models.

The intimacy of the HD 820 is uppermost. It’s a very real experience listening to music through these headphones. Play ‘Wild Horses’ by the Rolling Stones on Stripped[Virgin] and you suddenly grow a bandana. That sort of visceral.

And yet… it’s still a closed-back model and you can never fully shift that. The sound is a little more constrained, a bit more sinewy and muscular sounding in the upper mids. These aren’t big changes to the sound of the 800 series, but just the bits where you can’t cheat physics. Sennheiser gets pretty close to cheating physics here, but even the best closed back design is not an open design, and if you listen hard enough (especially if you have one of the open-back HD 800 models to compare) you can just hear where the closed-back sound kicks in.

I’m going to have to confess to something about the limitation to the HD 820: I didn’t hear it! It wasn’t that I missed the limitation, it’s that I’m not built right. Basically, your head size might dictate bass performance. I have a big head. Not just in ego, but my hat size is above average. Most of that extra space is taken up with storing trivia, but it means that the HD 820 was a snug fit around my ears and the width of my head meant the earcups seal easily. Not so my in-laws, some of whom are quite taken with the idea of trying out a pair of two grand headphones, and all of whom seem to have slimmer heads than most people. For me… “Wow! The bass on these things is incredible.” For them… “The bass? It’s OK I guess. Nothing to write home about.” I think the seal of those earcups is crucial and if you don’t (or, for head-shape issues, can’t) then you still get the outstanding midrange and treble, but the bass is only ‘pretty good!’ Unlike the HD 800 and HD 800 S, where the ear-cup could feel quite encompassing on the wrong head, this probably makes tonal differences. These could be resolved by swapping the stock earcups for stiffer leather or pleather designs.

 

This is only going to effect a small percentage of the prospective market for the Sennheiser HD 820. The rest are people who want an absolute top-flight open-backed headphone and ran into a shared living space issue. You can’t listen to HD 800 in the same room as someone else because they pump so much sound into the room, it’s like having a pair of small speakers tied to your ears. Sennheiser’s HD 820 gives you a surprising amount of the HD 800 S sound, but without all the leaking. You can listen to the BBC Proms with all the detail and edge-of-the-seat excitement they bring, all the while sitting next to someone quietly knitting and watching Midsomer Murderson TV.

TECHNICAL SPECIFICATIONS

  • Type: circumaural closed headphone
  • Frequency response: 4Hz–51kHz (-10dB)
  • Transducer principle: dynamic
  • Impedance: 300Ω
  • THD (1kHz, 1Vrms): < 0.02 %
  • Connectors: 6.3mm, XLR4
  • Cable length: 3m
  • Weight: 330g
  • Price: £1999.99

Manufactured by: Sennheiser Electronic GmbH & Co. KG

URL: en-uk.sennheiser.com

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Primare I35 integrated amplifier

I’m used to dealing with amplifiers. One look through the pages of any issue of Hi-Fi+ shows just that; my house regularly becomes cardboard and crate city this month. So, although there are models that impress, ones that really hit home are quite rare, and ones that actually shock you at how good they really are don’t come along that often, especially ones in the ‘doesn’t cost as much as a nice Mercedes’ category. I was expecting good things from the Primare I35 – the brand has a good reputation for making fine electronics – but frankly this one has me stumped. How did Primare make something this good… and it really is good!

The I35 is the first amplifier from the brand to feature its UFPD 2 amplifier modules, as distinct from the original UFPDs fitted to the last generation and models like the A60 power amplifier that remain on the order books. UFPD stands for Ultra Fast Power Device, an amplification module in a balanced configuration of four discrete amplifiers – two per channel. This Class D device has long provided instantaneous current delivery and extremely low distortion, but in its new UFPD 2 guise really lives up to that ‘Ultra Fast’ part of the acronym. It also means Primare can make a true 150 watt per channel amplifier in a relatively small chassis without making the box hotter than the surface of the sun.

Although we went amplifier-only purist at this time, the I35 is an extremely modular design, allowing a series of add-on board options to bring the amplifier from base model, through I35 DAC (with modular DAC board added) right through to I35 PRISMA (which adds a wired and wireless streaming board to the I35 and DAC option). While this takes the I35 into bold new places, there are a number of different system pathways and options, all of which are harder to justify if the top banana I35 is selected as standard. For example, you could configure the I35 as standard and use the matching CD35 PRISMA as digital hub, and connect via the analogue inputs to the I35, or you could do the same, but this time connecting the CD35 PRISMA to the optional DAC, place the PRISMA module in the amplifier, and connect the CD35 via digital or analogue inputs. Or, you could even opt for the DD35 CD transport and connect to the I35 DAC or the I35 PRISMA. Maybe in the future, Primare will add a phono stage module, and the number of optional combinations will achieve peak modularity!

Rather than opt for one of the variations, we went for the base platform. That being said, it’s not exactly ‘base’; with two sets of XLR balanced inputs, three RCA single-ended line inputs, and both fixed and variable outputs (hey, there might still be some people with cassette recorders… but more accurately this is for a home cinema processor).

 

The amplifier needs a little bit of running in. However I received it with some miles on the clock, so the amount of running in required is unclear, as is the degree of change that running in creates. Asking around suggests the running in process, and the changes it creates, are mild.

I plugged the I35 in and liked it. I changed the speakers (from LS3/5as to Wilson Duette II) and still l liked it. I swapped out cables, and I liked how it sounded. In fact, at no time and with no combination of bits and pieces I have to hand (and there are a lot of them) did it exhibit any ‘don’t like it’ properties or characteristics. OK, if you are going to use an amp-crushing full-range loudspeaker that costs as much as a small house then the I35 gets a little strained, but in the real world, you aren’t going to find a combination that doesn’t satisfy.

A big part of putting a smile on your face here is the combination of keeping a taut sense of rhythm throughout, and a sound that is extremely entertaining and attractive. A big way of determining this isn’t just listening to music; plug a TV or cable TV box into the amplifier and the designed-for-TV-speakers sound of something like Casualty[BBC-One] is transformed and you begin to realise the relative sophistication of the foley work, the effects, and the ability to pick out speech from a maelstrom of over-the-top plot devices. It’s hard to like this hack Saturday night ‘trauma-porn’ as it has been running for decades and ‘Holby’ has long run out of accidents to befall its hapless residents. But the I35 makes the programme entertaining like it once was.

It’s music, however, that will make or break the I35. And it’s music that the I35 does very, very well indeed. You’ll probably begin as I did, with several well-trodden pieces of music that are used for assessment but they will lead, and lead quickly, to the music of your youth, or the music of your passion. I realised I was on to something special when I found myself playing Louis Armstrong’s ‘West End Blues’ [Hot Fives and Sevens, JSP] which segued into ‘Another Girl, Another Planet’ by The Only Ones [Columbia]. These are core pieces of music for me. They hold special powers and only come out when the stars are aligned. Playing these tracks means I’m enjoying the music on an atavistic level and everything in the system is sounding great.

There’s something of the classic ‘Chrome Bumper’ Naim Audio sound about the Primare I35, both tonally and on that sheer musical enjoyment quotient that is so hard to pin down. Tonally, the I35 is rich and satisfying rather than bright and breezy, and yet it comes over as both energetic and dynamic sounding. These were all the elements that drove people into hi-fi stores in the 1980s, and all of those elements are improved here, with more detail, midrange clarity, and focus. Other aspects like soundstaging are also excellent, but it seems my personal preferences and priorities place that lower on the hierachy.

That’s perhaps the biggest thing about the Primare I35: it shakes the audio tree. Received wisdom held by some parts of the audiophile community states that there was a golden age of audio (defined as, “around the time my equipment was made”) that is unassailable in performance, and anything with Class D is an Agent of Satan. Sorry if my cynicism is brimming over here, but it’s products like the I35 that demonstrate the patent nonsense of these seemingly ineluctable audio truths. This is an amplifier that has the Devil’s Amplifier Class running cool and clear and it is extraordinarily modern in design inside and out. And yet, if you listen with your ears instead of your eyes and your prejudices, you’ll discover that this is an absolute blinder of an amplifier – possibly one of the best there is!

By virtue of ‘not taking the kids on holiday’ this month, my house has filled with very expensive amplifiers, and that gives me some perspective on what’s good, and what’s great. We are extremely lucky at this time because what’s good is outstanding, and this amplifier takes on some very big guns and wins. More buys you better as you might expect, and there are amplifiers that are brighter sounding, even richer or sweeter sounding, and ones that deliver way more power, volume headroom, dynamic range, and transparency. But here’s the thing, none of those amplifiers costs £3,200. What the I35 does is bring all of the good parts of audio with no sacrifices, skip all the bad parts, and make something that sounds sweet while it does its job.

 

I can’t help thinking that right now, this is perhaps the focus point in amplifiers. It’s the point where all the good things in audio come together, and beyond this you are more likely to get ‘more’ instead of ‘better’. OK, if you triple the cost of the I35, you begin to get back to ‘better’ as well as ‘more’, but the Primare I35 just does it all so well, it makes me question the need to spend more.

We sometimes try to describe products in a sound bite. It’s the ‘if I can sum this up in a single word…’ cliché, and I’m as guilty of it as the next scribe. With the Primare I35, though, sound bites don’t work because it’s more complex than that. So, instead, if I could try and describe the I35 as a person, it would be ‘a good bloke with whom I’d happily sink a few pints.’ Not showy or self-important… just entertaining to be around. As any British bloke will tell you, pub-related praise is the highest you can get!

TECHNICAL SPECIFICATIONS

  • Type: Integrated amplifier with optional internal streamer and DAC
  • Power output: 2 ×150W in 8 Ohms
  • Minimum load: 2 ohms
  • Analogue Inputs: 2 ×balanced (XLR), 3 ×unbalanced (RCA)
  • Line level Output: 2 ×unbalanced variable (RCA)
  • Frequency response: 20Hz–20kHz -0.2dB
  • Signal-to-noise ratio: > 100dB
  • THD+N: < 0.01%, 20Hz–20kHz, 10W at 8Ω
  • Dimensions (H×W×D): 10.6 ×43 ×42cm
  • Weight: 11kg
  • Price: £3,200

Manufactured by: Primare AB

URL: primare.com

Distributed in the UK by: Karma AV

URL: karma-av.co.uk

Tel: +44(0)1423 358 846

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Audio Research REF 160M mono power amplifiers

It’s funny, but Audio Research and McIntosh are all part of the same happy family, have so much in common, but are also miles apart. Both have their followers – in fact, both have followers who are loyal to the point of decades-long exclusivity – and both have an extensive portfolio of analogue and digital electronics (McIntosh’s interpretation of ‘extensive’ is not put through the high-end filter, however, and is more ‘comprehensive’ as a result). But, in all other manners, the two move in very different circles. Audio Research enthusiasts find those large VU meters in McIntosh products a bit garish.

So when the REF 160M came along with its central panel sporting a large, backlit VU meter, Audio Research’s enthusiasts… absolutely loved it. In fairness, the look of the VU meters on the Audio Research amps are more understated and less vivid blue than the ones on McIntosh models. The REF 160M is not all about the meters, but that’s the headline aspect of these excellent mono amplifiers. There is also a sense of design filtering through the whole ARC range now; this shares a lot of design cues with the influential, although now about to be defunct G-Series. The clever part is this also fits in with the styling of previous Audio Research models, which plays well to an audience who might have a collection of Audio Research designs dating back dozens of years. Classic, yet modern… nice!

This is something of a synthesis product, pulling together themes and concepts found in some of the best recent Audio Research products, which means some of the best-ever Audio Research products to most ears, as the company has been going through something of a golden age in the last dozen or so years. With models like the Reference 75SE, the company began to use the KT150 power valve. It’s now in virtually every amplifier the company makes. And, with the launch of the VT80 from the Foundation Series, the company started using a clever auto-bias system. This means no more adjusting the amplifier until a light goes out or the meter reaches its central position. It’s all done automatically now. This also means those four KT150 power valves on each channel can be exchanged for 6550, KT88, and KT120 valves and autobiasing takes care of the rest. That being said, you might want to ask ‘why’, when KT150s sound so damn good.

You can also switch between ‘ultralinear’ and ‘triode’ power on the fly, just by pressing a button on the front panel. The front panel changes from green to blue, the VU meters respond by leaping forward (ultralinear) or back (triode). The choice between ultralinear and triode is not completely clear-cut and depends on sonic demands and the loudspeaker used with the amps. You can even switch between single-ended and balanced operation, although this time with a rear-mounted toggle switch rather than from the front panel (that is perhaps more understandable as few are likely to switch from balanced to single-ended in the same way you might switch to and from triode operation. I would suspect the majority of REF 160M models will be used with other Reference Series models, which likely means defaulting to the balanced option every time, but that’s no bad thing as Audio Research power amplifiers frequently sound better in balanced operation.

 

That comparison to the Reference 75SE is not just there for show. The stereo chassis was a true revelation for many audio enthusiasts, as it was perhaps the best example of what Audio Research could do with a power amplifier, and the move from Reference 75 to Reference 75SE showed just how good the KT150 power valve really was. But the amp was more than this. It was the kind of amplifier that was almost universally loved. People who didn’t like Audio Research or were firmly wedded to solid-state ‘got it’ with the Reference 75SE. What it needed was a bigger model, and although the mono versions tried, they didn’t have quite the same magic as the stereo chassis. Fast forward to today and the REF 160M. Now we have a mono power amplifier with a simple valve configuration; just two 6H30s (one gain stage and one regulator) and four KT150s. Within that simplicity lies great finesse, like the Reference 75SE only bigger and mono.

I used the REF 160M primarily with an Audio Research REF 6 preamplifier (effectively forcing the balanced connection) because I suspect that will be how most REF 160M amplifiers will be fed. It was used with predominantly the excellent Sonus faber Amati Homage Tradition loudspeakers tested in issue 162. The front end was primarily an Audio Research Reference CD9 CD player, and cabling was by Transparent Audio. In other words, the kind of environment in which a pair of Audio Research amplifiers is most likely to appear. Granted this is the opposite of what might be considered a hostile environment for the REF 160M, but I’m not sure throwing the power amps way beyond their usual use case just to score points is necessarily honest reporting – it would be a little like a chef saying, “this is claimed to be the best frying pan in existence, but I used it as saucepan and it did a terrible job!” Context is all here, and even though the REF 160M is a flexible and fine-sounding performer in its own right, because it is a part of an extensive Audio Research system, because that system is so well respected in its own right, and because Audio Research customers are so loyal to the brand that now that the chances of them breaking out of using Audio Research is almost zero, an all-Audio Research system isn’t a ‘soft landing’… it’s looking at it in its appropriate environment.

In a way, I could almost cut and paste the review of the Reference 75SE, just removing the references to ‘possibly needing more power’ and have done with the review of the REF 160M. That’s because the effortless way the Reference 75SE handled music is reproduced perfectly here. That’s just the jumping off point, however. Yes, a product that did what the Reference 75SE did with more ‘oomph’ is an excellent addition in its own right (in fact, it was the most desired thing by ARC owners once they heard that stereo amplifier) and the REF 160M has that sublime musical ease, grace, and lack of granularity that made the Reference 75SE so loved, just with more power on tap. That, and that alone would justify the REF 160M and the review could end right there.

That would be the easy way out both for the review, but more importantly for Audio Research. Instead of ‘just’ making its best amp bigger, the company has made the whole concept better. That sense of effortlessness in terms of dynamic range, image projection (fore and aft), and image solidity – coupled with the kind of inner detail and microdynamic resolution that pins enthusiasts to the chair – not only remains undimmed but is actually considerably improved here.

My standard test discs for me are almost worn musically flat – ‘Memphis Soul Stew’ by King Curtis [King Curtis Live at Fillmore West, ATCO] is a fine example; every time I hear it, the enjoyment of the musicianship is replaced by a desire to reach for the notepad and start jotting! So, for an amplifier to cut through ‘review mode’ and not only make me listen to the track as a piece of music, but then continue deeper into the album again (at least until the so-so version of ‘Whole Lotta Love’, which fails the test of time in my opinion)… that suggests an amplifier that combines excellent detail resolution and dynamic range, with something akin to a ‘musical passion reset button.’ Yes, of course the imaging is superb (it’s an ARC power amplifier – the day one of those doesn’t do superb imaging as standard is the day the high-end audio world closes for business), and the way you can follow individual themes within the musical whole is inspiring (it’s the reason that ‘Memphis Soul Stew’ track gets used), but there is also an organic nature to the sound of the REF 160M that simply doesn’t happen with many other amplifiers. Music – all kinds of music – breathesthrough the REF 160M, and it perhaps goes some way to explain the preponderance of late-1950s jazz in audio. This music is all about ‘feel’ and so is an amplifier like the REF 160M.  Playing ‘Make It Good’ from Luke Pearson’s The Right Touch [Blue Note XRCD] highlights this perfectly: the interplay between Pearson and Freddie Hubbard on trumpet in the bridge needs an amplifier that has that sense of musical ‘breathing’ and as a consequence, the REF 160M shines here.

There is so much more, and you could include every musical style and genre for examples. How the REF 160M deals with vocals are sublime, for example, the singer is standing there, between the speakers, singing for you, almost as if the microphone and recording chain fell away. The little finger squeaks on a fretboard are also tell-tale signs of quality because they root you in a seemingly more realistic environment than normal, and the REF 160M delivers that kind of inner detail with ease and aplomb. But this falls into a trap the REF 160M never hits; these individual aspects of a performance can suggest a product is simply a collection of sublime moments, with no overall cohesiveness. The REF 160M ties these sublime moments together to make an even more sublime gestalt. The sum of the parts is excellent, but the whole takes things to new levels.

Finally, there is something so eminently satisfying about the sound of the REF 160M. There is no other word for this, but don’t confound ‘satisfying’ with ‘smug’. You put on a piece of music and the stresses of the day are gently removed with a sense of satisfaction that normally comes from a good single malt or gin and tonic. Other products also do this, but the REF 160M does it faster, leaving you ready for more music. Power them up, and by the end of the first track you played, you are fully chillaxed. That might take an hour of listening in some systems, but the REF 160M puts you in your musical happy place inside of the first five minutes. Yes, that sets you up for extended listening sessions without fatigue, but for the time-poor, it also means you can get into that more calm and cerebral place music can take you far faster than usual. Of course, if you don’t want ‘calm and cerebral’, slam on some Infected Mushroom, turn up the volume and enjoy the energy pump it creates. The REF 160M doesn’t differentiate and is just as comfortable playing music at cobweb shake-out levels.

 

Back when the Reference 75SE hit the streets, what we wanted was a bigger version. Now the roles are reversed; what we want is a REF 160M but in a stereo chassis. Fortunately, that is on its way, and much is anticipated and expected from that upcoming stereo power amplifier.

The headline-grabbing part of the Audio Research REF 160M is those big, see-through VU meters, but you’ll note they barely got a look-in during the review. They are great to have and look wonderful when the music plays, but you quickly realise that the REF 160M is more than just a pair of meters; it’s a wonderful pair of power amplifiers in their own right. I’ve played with a number of Audio Research amps over the years, many of which have been some of the most memorable musical experiences I’ve had, but I can’t shake the notion that this is the best of them. It’s so musically faithful yet so musically entertaining and enjoyable, this takes the already high standards of Audio Research and raises them to new levels. It delivers grace, space, and no small dose of pace, too. This is a rare jewel; one of the best ever!

TECHNICAL SPECIFICATIONS

  • Type: mono valve power amplifier
  • Tubes Required: Two matched pair KT150 (Power output V1-4); Two 6H30 (Gain stage V5 and V6)
  • Power Output: 140 watts per channel
  • Power Bandwidth: (-3dB points) 5Hz to 70kHz
  • Frequency Response: (-3dB points at 1 watt) 0.5Hz to 110 kHz
  • Input Sensitivity: 2.4V RMS Balanced for rated output. (25.5 dB gain into 8 ohms.)
  • Input Impedance: 200K ohms Balanced
  • Output Taps: 4, 8, 16 ohms
  • Output Regulation: Approximately 0.6dB 16 ohm load to open circuit (Damping factor approximately 10)
  • Overall Negative Feedback: 14dB
  • Slew Rate: 13 volts/microsecond
  • Rise Time: 2.0 microseconds
  • Hum & Noise: Less than 0.2mV RMS – 110dB below rated output (IHF-A weighted, input shorted, 16 ohm output)
  • Power Supply Energy Storage: Approximately 900 joules
  • Power Requirements: 105–130VAC 60Hz/260-250VAC 50Hz. 400 watts at rated output, 700 watts maximum, 260 watts at ‘idle,’ 1 watt off
  • Dimensions (W×D×H):
    43.8 ×47 ×25.4 cm. Handles extend 5.1 cm forward
  • Weight: 25.5 kg ea
  • Finiosh: Natural or Black
  • Price: £28,998 per pair

Manufactured by: Audio Research

URL: audioresearch.com

Distributed in the UK by: Absolute Sounds

URL: absolutesounds.com

Tel: +44(0)208 971 3909

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Chartwell SUB3 subwoofer

It is a truth universally acknowledged, that a pair of LS3/5a loudspeakers in good condition, must be in want of a bit more bass. OK, so my days as Jane Austen’s stunt-writer are somewhat numbered, but you get the point. The LS3/5a (in all its guises, even including the LS3/5) is a little bit light in the bass, in that there is precious little content below about 100Hz. The usual way to boost this is with a subwoofer, and typically today that means a powered subwoofer. The Chartwell SUB3 by Graham Audio is the notable exception; it is a passive bass cabinet designed specifically for the classic BBC design, and adds a little bit more bottom end to the classic broadcast bookshelf. As Chartwell also makes both the LS3/5 and a version of the LS3/5a, it’s a logical add-on.

Like all Chartwell and Graham Audio designs, the SUB3 use the company’s own Volt-built design drive units, and is the work of Derek Hughes, son of Spencer and Dorothy Hughes (of Spendor fame), and one of the keepers of the BBC flame. The SUB3 is a small, bass-extension cabinet, effectively a sealed box upper chamber containing a 155mm Graham/Volt bass driver and a crossover, with the lower chamber containing a port constrained by a foam bung. There is no internal damping or wadding, and the thin-walled cabinet doesn’t even feature any bitumenised internal wall cabinet treatment. Connections amount to two pairs of speaker terminals; one from the amp to the SUB3, and one from the SUB3 to the LS3/5 or LS3/5a.

The front baffle (I’m not even sure if that’s the right word, given there is no front-firing bass driver) is sloping slightly, otherwise the SUB3 is a perfect cube, and sits on a quartet of spikes. Although sold in pairs, they are identical, and each is designed to sit between your amp and your loudspeaker, both electrically and physically. Ideally, the SUB3 should sit close to the wall behind each LS3/5 or LS3/5a, rather than next to it. This helps provide some boundary reinforcement, and – from a purely room acoustics point of view – the single worst place to put a bass loudspeaker of any description is the place where the loudspeakers typically sit in the room. So, having these bass speakers set back is a good thing; just make sure this isn’t an attempt to add small speakers into a massive room and have several metres between speaker and sub. As there is no phase control (no controls of any kind, in fact), setting the SUB3 far back in the room and having the main loudspeakers 3m or more into the room could put the bass slightly out of sorts with the sound from the BBC designs.

As the principle changes between the LS3/5 and LS3/5a involve the high-frequency driver and crossover, the SUB3 is designed to fit in with both, extending the bass of the speaker into the double-digit zone. Chartwell claim a response down to 35Hz, and while that might be the case, there’s not much going on at that bottom end of the bottom end. Instead, a real-world in-room response is going to be something nearer to about 50Hz. This is still a marked increase in bass compared to the 100Hz of the main loudspeaker.

This is a one-trick pony, but it’s a very good trick. The SUB3 is designed to only work with the BBC loudspeakers, and even matches the impedance of an LS3/5 or LS3/5a loudspeaker (although in fairness some of the more odd BBC-derived loads will work, but the impedance mis-match is not ideal), and Chartwell supplied a pair of LS3/5 (and a set of Something Solid stands designed specifically for that cabinet size). It uses a fourth-order bandpass crossover, meaning it has no interaction with the loudspeaker itself, and it just kicks in below the end-point of the LS3/5 or LS3/5a. As that design comes to a fairly abrupt stop around 100Hz, the SUB3 fills in the spot from 100Hz down to (theoretically) 35Hz. If you play the SUB3 without a loudspeaker connected, you hear just how effective that bandpass really is; the speaker has a sharp stop at 100Hz where almost no frequencies above that leak through. The character of the loudspeaker remains untouched through the SUB3… almost. If you don’t get the installation right, there is either slight bloom and exaggeration between bass and sub-bass, or the reverse happens: a very slight gap at the inflection point where SUB3 ends and LS3/5 begins, almost as if the two products were teenagers at a prom night, hugging the walls and afraid to dance with one another. Get it right, though, and it’s like someone put on the Barry White records (I’m showing my age here!). When it’s all done properly, the two interact seamlessly and the tonal balance is nigh on perfect.

 

It’s an easy product to discuss because this is an LS3/5a only with more bass. It doesn’t change the LS3/5 or LS3/5a for the better or for the worse, it just adds more bass to the proceedings, and that bass is in keeping and in character with the BBC design. It’s precise, accurate, and a little bit laid-back. It’s not the most dynamic subwoofer sound, but neither should it be if it is to retain what makes the LS3/5a an LS3/5a.

The bass extension isn’t enough to make the LS3/5a fill a bigger room, nor is it fast and deep enough to make the loudspeaker the first choice for drum ‘n’ bass, dubstep, or grime. But, I’d suggest that the LS3/5a probably isn’t your first port of call if you are playing back to back Stormzy cuts. On the other hand, if you chose the LS3/5 or LS3/5a and love what it does but would just like it to do a little more at the bottom end, then the SUB3 is the perfect choice. The SUB3 rounds down and rounds off the LS3/5 to modern ears, too; we are used to small loudspeakers packing more of a bass punch today, and while the SUB3 isn’t big on ‘punch’ it does bass extension and gives extra texture in those bottom octaves.

I am loathe to rely simply on classical music for this, in part because the association with the LS3/5a and classical music is almost a cliché, but the recording that best encapsulates what the SUB3 does best is Paul Galbraith’s interpretations of Bach Sonatas and Partitas for the violin [Delos], played on an eight string guitar held like a cello. This unique instrument has a sound akin to a Spanish guitar but has a richness of tone and depth of bass that is lost to the LS3/5a (it just sounds like a guitar), but with the SUB3 in place, those last two bass strings are more sonorous and resonant, and the difference between this and the instrument of Segovia shines through. A larger orchestral piece shows the LS3/5 or LS3/5a has more substance, some weight, and greater majesty to the sound.  But such things are relative, and anyone expecting a full-range sound from a small speaker are going to be disappointed. That being said, the LS3/5 and LS3/5a are small speakers for a small room, and in that small room context, I suspect the SUB3 might just be as much bass as the room can take.

Moving over to the rock end of the spectrum, the bass from the SUB3 is more ‘majestic’ than ‘fast.’ This works really well in adding some bottom end solidity to classic prog works from the likes of Pink Floyd. It’s worth noting, however, that while listening to Fragileby Yes [Atlantic], this showed where the SUB3 both worked very well and didn’t quite keep up. Tracks like ‘We Have Heaven’ and even the bass-oriented ‘South Side of the Sky’ were excellent and the SUB3 really filled in the bass perfectly, but the opening ‘Roundabout’ was a little too fast-paced, for both the LS3/5 and the SUB3. A bigger loudspeaker (if that fits your room) or a well-installed active subwoofer would give both the speed and depth needed to play this track with the kind of intensity it requires, but that would change the nature of the LS3/5 or LS3/5a in the process, thereby defeating the object of the exercise somewhat. I think many existing owners of the classic BBC speaker would happily go for a bass add-on that retains the loudspeaker’s agility than impose a new character.

The LS3/5 and LS3/5a are icons of classic British audio, and the SUB3 extends that icon further into the bass without tampering with what makes the LS3/5a so special in the first place. Those who have lusted after LS3/5 or LS3/5a designs – or those who already own a pair – will accept no substitute and brook no change to the design. For them, the SUB3 is a perfect solution to the ‘not a lot of bass’ problem inherent to that iconic loudspeaker. That classic BBC small monitor for small rooms need not sound quite so small now.

TECHNICAL SPECIFICATIONS

  • Type: passive subwoofer
  • Frequency response: 35Hz–100Hz
  • Nominal impedance: 8Ω
  • Sensitivity: 84dB SPL (2.83W, 1m)
  • Recommended amplifier power:
    30–80W programme (unclipped)
  • Crossover: 4th order bandpass
  • Finish: Real wood veneer
  • Dimensions (W×H×D): 30 ×30 ×34
  • Price: £1,995

Manufactured by: Chartwell

URL: grahamaudio.co.uk

Tel: +44(0)1626 361168

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Meet Your Maker: Xuanqian Wang of AURALiC

AURALiC hit the ground running a few years ago with its affordable range of digital audio products designed for audiophile and headphonista alike. That would be enough for most brands and we’d see nothing more from the company for a decade. Instead, AURALiC showed the world the G2 series, and the world took notice. It’s rare to find a product line that commands such universal respect anywhere in the audio business. Even what should be bitter rivals say surprisingly good things about AURALiC’s line-up.

A part of this comes down to AURALiC’s linchpin, Xuanqian Wang. He’s the real deal. Not only is he an extremely good audio designer, and something of an engineer’s engineer, he’s also a surprisingly disarming person to talk to, mercifully free from the Great And All-Powerful Ego that seems to come with the job for many leaders of audio companies. We spoke to Xuanqian Wang during the Munich High End show about the G2 series and the launch of the new GX Femto clock.

The G2 series was a radical departure from the original ARIES streamer and VEGA processor. What has changed in the ARIES G2?

The ARIESG2 is a complete evolution of the original award-winning ARIES. We have introduced many new features. It’s quite an extensive list! – our new proprietary Tesla G2 platform incorporates a 1.2GHz quad-core processor, 2Ghz of memory and 8 Gigabytes of data storage, dual galvanic isolation, improved Femto clock, dual Pure-Power internal linear power supply and optional internal 2.5 inch SSD or HDD storage with no capacity limitation so our customers can potentially store an entire collection of music within theARIESG2 for the ultimate convenience and speed. We build all of this technology in to a precision made, CNC-machined ‘uniti chassis’ hewn from a solid billet of aluminium fitted with custom made isolation supports. We paid a good deal of attention to the experience of using the product so we use a beautiful 3.97 inch Retina-resolution colour display and metal control buttons, which enable full music library access and product set up on screen. 

What has changed in the VEGA G2?

Our original VEGAwas a pure digital to analogue convertor which attracted many customers largely due to its very natural, fatigue free sound quality. VEGA, together with the original ARIES, accelerated the growth of our company in quite a short space of time. In VEGAG2 we wanted to implement our latest technologies, many as featured in our ARIESG2 with the addition of our own resistive ladder fully analogue volume control and dedicated analogue input which enables users to achieve tremendous performance from analogue sources, such as a top-flight turntable and phono stage. Furthermore, we developed our own proprietary ‘Lightning Link’ interface to connect G series products together to facilitate multi-product operation which is important in order to incorporate our ARIESG2 and LEOGX Reference Clock. Last, but not least, we have implemented streaming functions in to VEGAG2 for customers who require the simplicity of one unit that can simply be connected to a pair of active loudspeakers or stereo power amplifier. 

The original line included the ALTAIR wireless streaming DAC and the POLARIS wireless streaming integrated amplifier. Why are they missing from the G2 Series?

The G series is a big change and progression for our product range – it not only has a different style, but also uses different technologies which are higher in cost. POLARISand ALTAIRstill offer great performance and value for money.

 

The LEOGX is your first Reference Master Clock. What makes it stand out against its rivals?

LEO GX is a breakthrough in digital audio system clocking — the first master clock ever that can work with a DAC directly taking control of the VEGAG2 clock. Instead of merely synchronizing with the LEO GX, the VEGA G2 actually uses the exceptionally high frequency incoming clock from the LEO GX directly as its own working signal. In other words, the LEO GX bypasses the internal VEGA G2 clock circuit entirely and drives waveform creation directly with its signal. No more PLL (phase-locked loop), and no more limitations.

The LEO GX clock is so precise that existing benchmarks aren’t detailed enough to accurately represent what it can do. Instead, we use Allan deviation to describe the resolution of the LEO GX, which is like looking at phase noise closely enough to detect shifts of +/-1Hz or even +/-0.1Hz. The Allan deviation of the LEO GX Reference Master Clock comes in at 2E-12 (at 1 second), which is equal to a 10MHz rubidium atomic clock with phase noise of +/-1Hz at -110dBc/Hz, or an amazing 500 times less jitter than an 82fs Femto clock oscillator.

Why ‘LEOGX’ as opposed to ‘LEOG2’?

LEO takes the “X” designation however because its clocking duties will be globally applicable to future G Series systems as well. So if we offer next-generation models down the road, LEO GX will remain compatible with any updated G series DACs.

Describe the steps for someone building a G2-Series digital system. Is there a universal progression as you go from one box to the complete system?

G2 series is designed to be very flexible with products to suit different applications. For instance, ARIESG2 is perfect for those wanting to add top performance streaming to a system, with the option of internal storage, which already has a DAC because the unit is designed with digital out on S/PDIF and USB — I think that’s why the original ARIESwas so popular finding its way in to many high-end separates systems. The VEGAG2 will further improve the performance when connected with ‘Lightning Link’ to anARIESG2 if a pre-amplifier is required. That said, VEGAG2 will operate as a stand-alone streaming DAC in its own right if the requirement is for a one box solution. Optimum performance is achieved when using the LEOGX with the VEGAG2, ARIESG2, and ‘Lightning Link’ connected. Performance is extraordinary and pushes the performance of what is achievable from streamed digital audio sources. 

Which product in the G2-Series surprised you by being hardest to design, and why? 

VEGA G2 has such a unique structure that the design process has taken a considerable period of time. VEGA G2 is virtually a ‘digital recorder’ that records all incoming digital signals to our Tesla platform for precision buffering and processing – this methodology of design is an example of the numerous technologies we employ in striving for authentic, natural sound. Hardware and software design is challenging and complex, but I really enjoy the process and it’s immensely rewarding. 

Which G2-Series product surprised you by its performance, and why?

That’s a tricky question. I can’t single out one product. During long-term design and research, we’ve reached the conclusion that it is hard to build up a solid basis for development by solely relying on either instrument testing or attentive listening. Only with the discovery of the link between scientific data and auditory sense can we succeed in seeking reliable criteria of evaluation during the R&D process. As a result, we set up mathematical models between our subjective listening experiences and objective measurements at the very beginning of the development process. We’ve expanded all of our R&D work based on these mathematical models. With this methodical approach, we really feel all products we produce don’t have surprises, but a thoroughly ‘designed’ level of performance and are real value for money. 

Is the ‘computer and DAC’ dead in high-end, high-resolution audio?

Yes, the original reason that people listened to music through their computer was because it was the only way to manage a music library and play high resolution music. Right now, we have all kinds of different music streamers on the the market; most streamers use the Linux system with USB audio outputs and support all PCM and DSD sampling rates. There is no reason to keep a noisy computer in the listening room anymore. We’re also starting to see many customers move away from storing their music, toward streaming from high resolution services such as Qobuz at up to 24-bit 192Khz. The indicators are that more and more people like to access all their favorite music they may have purchased on CD together with new music in great quality from a high quality streaming service – its like visiting a record store to browse for new and interesting music anytime you like. Fewer people store their music now in large parts of the EU. 

How important is flexibility in app control today? Do you prefer people adopting a rigid set of apps, or like people to experiment? Why?

The control interface of a music streamer is so important and can make a product a success or failure. The convenience of usage is the first priority when we design the control application. We developed our app for IOS on iPad and iPhone, but third-party apps for IOS and Android also work. I have seen so many people make decision to buy an AURALiC streamer just because of our app. Lightning DS is, again, our own proprietary design and something we’re very proud of. The interface is highly intuitive and engaging – the layout of text, artist & album information, crisp album artwork, suggestions for further listening all contribute to an enjoyable user experience. We believe it’s absolutely the best way to browse and enjoy listening to music. 

What do you think will be the next big innovation in digital?

Digital signal processing will be the next big thing in digital audio. We have been actively developing a variety of real high-end quality signal processing algorithms for a long time. Taking upsampling as an example, we have developed an algorithm that can upsample all incoming signals to DSD512 format with quality beyond measurement. To run this algorithm in real time, we have to use an FPGA chip thant cost about £10,000 five years ago, but we have recently successfully made it run on a £2,000 processing platform since the processors are today lower cost and more powerful. I believe we will be able to make this upsampling technology available in the next few years.

Hegel Music Systems H590 integrated amplifier

Here is the big one: Hegel’s top of the tree. The H590 from Hegel Music Systems is not only the biggest integrated amplifier the company has ever produced, but it’s also the most connected, the most forward-thinking, and – in outright performance terms – probably its best yet. Granted there are a couple of pre/power combinations in the line-up that might have something to say about that (especially the 1,100W H30 mono brutes), but I’m holding to that statement.

The H590 is the synthesis of the best of the latest line of integrated amplifiers (such as the innate flexibility of the Hegel Röst and later designs), coupled with the most up-to-date versions of all the amplifier technologies Hegel has incorporated into its amplifiers for the longest time. Now mix in the kind of ‘best in show’ components and technology so new it gets its first outing here and you have an unbeatable combination.

The Hegel H590 adds more power to the likes of the Röst, H90, and H190, and it brings more power and connectivity to the H360. With its strangely precise 301W per channel, you could be mistaken for thinking the H590 occupies the top slot of Hegel’s integrated amp line-up simply by virtue of power delivery. If you need a bigger amplifier and the H360 won’t cut it, then the H590 is all you need. While true on the surface, this is too simplistic a reading of the situation. Interestingly, the price of the HD30 flagship DAC from the company and the H360 is not that dissimilar to the full-up H590, and until this model shipped, this was probably the best Hegel set-up you could buy. The H590 effectively obsoletes that combination, as you won’t buy both when the H590 performs this well.

Like the other integrated models in Hegel’s line-up, the H590 features an extensive onboard digital audio section and analogue inputs. Unlike those other integrated models, however, the H590 does not place limits on either in order to fit on the back panel. So, you get a trio of stereo RCA line inputs, and two sets of XLR balanced line inputs (as well as fixed and variable RCA stereo outputs) on the analogue side, and two coaxial (one of which uses BNC), three optical, USB, and Ethernet digital inputs, and even a BNC coaxial output.

That is an exceptionally comprehensive line-up for an integrated amplifier, reflecting the does-it-all nature of the Hegel H590. There are a couple of obvious omissions, however; no phono stage and no headphone socket. The first is perhaps more understandable than the latter, as Hegel has long eschewed turntable as one of its regular sources, preferring instead to allow the end user to specify their own analogue front-end. While those seeking an all-Hegel electronics solution that includes turntable replay might want a standalone phono stage from the brand, the onboard equaliser in an amplifier is now a rarity.

The absence of a headphone socket is more odd, as Hegel makes an extremely good headphone amplifier circuit in its own right on all the other integrated models in the line-up. Hegel is extremely adept at reading the demands of its customers, however, and I suspect the absence of a headphone amplifier is no accident.

Hegel’s design criteria is reduced to a series of pithy names that aptly describe aspects of the technology, including the localised feed-forward amplifier circuit called SoundEngine, DualAmp (which separates out the voltage and current gain stages) and the related DualPower (which provides specific power supply feeds for those separated parts of the amplifier circuit), and finally OrganicSound that requires careful voicing of the amplifier against a known reference of acoustic instruments and vocalists not known for their love of AutoTune. There are a similar group of names for the digital audio side of things, including SynchroDAC (synchronised – as opposed to asynchronous – upsampling) that goes with the company’s LineDriver technology (high-frequency filtration), a similarly synchronous USB technology, all controlled by pico-second accurate MasterClock. All of the technologies underlying these names have been improved in the process of developing the H590, and you can hear this.

 

Stepping out of HegelWorld for the moment, the nuts and bolts of the H590 are extremely impressive. That power amplifier stage delivers its 301Watts in Class AB, but it’s a high-bias Class AB making it run in Class A for longer. The power amp’s output is achieved by using 12 output devices per channel, and a huge power supply transformer (which accounts for the height of the amp). On the digital side, this is the first domestic product in the audio world to sport the latest AKM chipset and this meant a lot of coding performed by Hegel’s team itself. The benefit of this is it brings the second-generation of MQA processing to the table, alongside PCM to 32-bit /384kHz and DSD 256 (on USB).

The coding part is really clever because it allows the user to very simply utilise Tidal’s services and leverage MQA extremely easily. It allows true second-generation MQA unfold internally, which means you tell Tidal (via your phone or tablet) to send an authenticated MQA file directly from a router to full decode inside the H590, with no intermediary unpacks or handshakes. Making Hegel’s H590 the Steve Austin/Six Million Dollar Man version of MQA decoding: better, stronger, faster (although without the Bionic Eye and Power Arm).

Setting up the digital side is extremely easy now. The amp has its own Network Configuration page and if connected to a wired router, press and hold a button a couple of times and up pops the name and IP address of the H590. Type that into a browser on a computer and you can update the firmware, reassign the name and IP address for a more complex multiroom system, or play dating agency between the H590 (acting as media renderer) and a UPnP/DNLA compatible media player. Similarly, it’s easy to hook the H590 to AirPlay or Spotify Connect by adding an Ethernet cable to the appropriate wireless router. Both AirPlay and Spotify ‘see’ the H590 as a compatible/available device, and you simply connect your iDevice or similar to the H590 and away you play. This is one of those installation concerns that is more complex to describe in detail than it is to do in reality (rather like making toast – imagine describing the process in minute detail and it appears mindbendingly difficult).

I have a bit of a problem with ‘flagships’. Sometimes, they have an alarming habit of going for the impressive so much that they undermine what was so good about the more attainably-priced models. It’s a belt-and-braces approach that makes for a bigger amplifier, but not necessarily a better one. It’s a problem in reverse, too; the company that started out at the top of Mount Olympus often fails to make the less expensive models live up to expectation. So, there was a bit of a concern that Hegel might go a bit ‘flashy’ in making The Big One.

I needn’t have worried. Given its northerly latitude (shared with Disenchantment Bay in Alaska), it’s probably not that difficult to retain a cool head in Oslo, and cooler intellects than mine made the H590 retain the advantages of the smaller Hegels, with just the right amount of extra heft and all-important resolution to more than justify its position at the head of the family. Just give it an hour to warm through.

There are a few electronics companies that gain a lot of support and followers among loudspeaker designers because these brand’s amplifiers ‘do no wrong’; in other words, they make a great neutral platform for the loudspeaker designer to weave their own product, and a perfect demonstration product for the company to showcase their new loudspeakers, knowing the amplifier will handle everything thrown at it. These are ‘…just add loudspeakers!’ designs that dealers love, too. Hegel is one such company and the H590 extends that ‘…just add loudspeakers!’ ethos to some very demanding partners and spaces. From the perspective of an audio reviewer, there is nothing better than an amplifier that I know will satisfy the majority of prospective buyers regardless of their tastes in music, the loudspeakers they currently use, or the loudspeakers they might intend to buy next time around. And, while Hegel gets demonstrated a lot of the time with Nordost cable and KEF, you could partner the H590 with practically everything and it would make friends and make everything talk to everything else. It’s like the Rosetta Stone of amplifiers.

That makes describing the H590’s sonic performance easy. It gives the music and the loudspeakers what they want. And it does it better than many by doing less, rather than more. The old canard of ‘sins of commission and omission’ is apt here. In all its designs, Hegel doesn’t ‘do’ commission: if you are looking for an amplifier that pretties up the sound of your music, or adds a bit of thickening bottom end to fill in the gaps in your loudspeaker, look elsewhere, The Hegel’s sing honest and true. But, the smaller models do some small amount of omission if you are looking for a big amp to drive a big speaker. Yes, they punch above their weight (the inherent honesty of the design makes the H90 a surprisingly great partner for the Wilson Duette Series 2) but there is still a limit to this, and that’s where the H590 comes in. It doesn’t do ‘limits’ either.

The H590 doesn’t sound obviously or overtly powerful… until you need those power reserves. Then they are subtly introduced. Nothing showy or flashy, you just realise that the amplifier is doing all you want from an amplifier and driving a pair of loudspeakers absolutely correctly. You then flip between musical genres, taking in everything from fey girl with guitar sounds (I went with the now somewhat rusty sounding ‘Mushaboom’ by Feist from her Let It Diealbum on Interscope records, and her diction and articulation was nigh on perfect, and the handclappy percussion was deftly separated) right up to full-thickness orchestral works [Mahler’s Eighth Symphony, Solti and the Chicago SO, Decca] and at no time did the H590 give away its size, its limits, or did it ever give up gripping those loudspeakers. Basically, unless you are using the Apogee Divas from the 1980s, there isn’t a loudspeaker in Christendom that the H590 can’t drive.

It’s not just about brute force. The amplifier has subtlety, dynamic range, texture, resolution, rhythm, and outstanding soundstaging properties. None of which are drawn to your attention; you just like the sound. If there is a character to Hegel’s sound – common to the breed – it’s a very slight forwardness that gives a little bit of a zing to the upper-mids. This is not an excessively bright and over-energetic sound, but just a tiny bit of pep in the Hegel’s step.

 

The DAC is a resolution monster. There is more detail on offer here than many good standalone DACs. In fact, it’s good enough to make you wonder whether the company’s own HD30 is worth the investment! I’m MQA-agnostic (when it sounds good, it sounds great… other great-sounding formats are available) but I couldn’t help but be enthralled by the sound of the best in MQA. There is ‘some’ inverted snobbery in the audio industry, but the MQA version of Beyoncé’s ‘Sandcastles’ and the intro to ‘Daddy Lessons’ [both from Lemonade, Columbia] are outstanding pieces of work. The combination of effortless ease and the excellent sound make the H590 something of an MQA ambassador.

All up, the Hegel H590 ultimately asks some difficult questions of the audio amp world. This is the ‘straight wire with gain’ for the high-end world. More (in most cases) buys you a shinier case, a greater number of boxes and some extra hoops to jump through. Unless you need that kilowatt power amplifier to drive your difficult loudspeakers to PA levels, the Hegel H590 might just be all you will ever need.

TECHNICAL SPECIFICATIONS

Type: Integrated amplifier with network connected DAC

Power output: 2 ×301 W into 8 Ohms

Minimum load: 2 Ohms

Analogue inputs: 2 ×balanced (XLR), 3 ×unbalanced (RCA)

Digital inputs: 1x BNC 75Ω S/PDIF, 2 ×coaxial S/PDIF, 3×optical S/PDIF, 1 × USB, 1 ×RJ45 Ethernet

Line level output: 2 ×unbalanced variable (RCA)

Diigital outputs: 1x BNC 75Ω S/PDIF

Frequency response: 5 Hz–100 kHz

Signal-to-noise ratio: More than 100 dB

Crosstalk: Less than -100 dB

Distortion: Less than 0.01% @ 50 W 8 Ohms 1kHz

Intermodulation: Less than 0.01% (19 kHz + 20 kHz)

Damping factor: More than 4000 (main power output stage)

Dimensions (H×W×D): 17.1 ×43cm ×44.5cm

Weight: 22kg

Price: £9,000

Manufactured by: Hegel Music Systems

URL: hegel.com

Tel: +44(0)7917 685759

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Simaudio Moon 600I V2 Evolution Series integrated amplifier

Many moons ago (yeah, I know), I was given the opportunity to review a compact little integrated amplifier from the Canadian manufacturer SimAudio. It was called the Moon i-3. Outwardly it was a completely no-frills design, beautifully constructed, with a large volume control and a very reasonable price tag. As ever, competition at its price point was fierce. I fired it up… and thought it sounded rather thin and lightweight. Discussing this with the then-editor we came to the decision that it was promising enough to take time over so we kicked the review back a couple of issues. It went into an upstairs bedroom playing on endless repeat for several weeks. When re-installed I had one of those moments in audio that has stayed with me. I was never going to get caught out like that again. To say that it was unrecognisable would be an understatement. It had unfolded and evolved musically to such an extent that it became a truly captivating little thing. It had speed, decent power, lovely tonality, and an unflustered refinement that belied its humble cost (if memory serves, it was under £1,500 at the time). But the name Moon became synonymous, to me, with very lengthy run-in times and I believe I am not alone among reviewers in that view.

So, given the opportunity to audition a new Moon integrated amplifier, I was very keen to hear how things had developed. The lengthy preamble here is merely to give a bit of a background flavour to the history of my relationship with Moon products and the 600i V2 has proved to me that all of those core values of their sound and performance are still there in abundance. I should add here that I have no experience with the V1 version of this amplifier that was in production for around eight years. The source components and speakers I am using are different and very much improved, but Moon and its clear musical focus are still making gimmick-free amplifiers like the 600i V2, which is a very good and reassuring thing. The hereditary line from that little i-3 all those years ago to the very chunky integrated currently sitting across the room is evident every time it opens its mouth.

But, the 600i V2 actually sounded very decent to me, straight from the sealed box. A little ‘green’ perhaps, but essentially all there, so I just left it in the main system doing its stuff and heard it putting on weight, colour, and substance while growing sharper and faster over the weeks. The system I used was purposely chosen to stretch it. A dCS Vivaldi with CD transport and DAC and a full Roon/Tidal streaming capability feeds it while Nordost cabling connects it to a pair of the quite superb Wilson Duette Seires-2 loudspeakers. With such high-end potential, I would usually advocate the sort of amplifier that would cost considerably more. This is conventional advice really for such a system, but I have to say that the Moon has been putting in such a performance that I can only admire the musical completeness of its design and the way that Simaudio have crafted and voiced this little gem. There was certainly a slight thin astringency to horns and a pinched, raw-edged flavour to the attack of cymbals initially but, as the hours and days passed, this vanished without becoming over-smooth or ignoring the instrumental characteristics that should be there.

It is an extremely solidly built, purposeful-looking integrated amplifier. I find the design really nice too. The slope shouldered front panel looks great. The review sample was in black but, personally, I would opt for the two-tone version with the aluminium-edge features. There are no built-in DACs or digital interfaces of any kind on the 600i V2. Its impressive weight is due to a pair of huge toroidal transformers powering each side of the dual mono design. The chassis, power switch and mains socket are the only parts shared by the two channels. It is designated as a NFN or ‘no overall feedback’ amplifier that runs in Class A for the first five watts of its considerable output (125 watts into 8 ohms) But its ‘straightforward’ design features more depth than might initially be apparent. For a start, there is the onboard software that enables you to independently name each of the five line inputs and assign a maximum volume level to each one and create an ‘offset’ level from -10dB to +10dB or even to bypass the control altogether, freeing the amplifier to be controlled by an onboard version on a source component, effectively leaving the 600i V2 as a power amplifier. In a way it’s a shame to do that because the Moon’s volume control is a joy to use. Simaudio have always been good with volume controls. The large knob, with its buttery smooth action is connected to a precision optical encoder where metal-film resistors do the gain work. Moon have obviously taken considerable care with this as it can provide no less than 530 settings. Few will need such precision in practice but the rate of increase or retardation is governed by the speed with which you operate the control. Do it slowly and the increments will be as little as 0.1dB per step. Approach it more robustly and this becomes a single dB. It is therefore easy to make volume changes precisely and indeed minutely. Moon claim that this design has eliminated any unwanted side-effects usually found with potentiometer circuits and I have little doubt that it makes a significant contribution to how clean and precise the amplifier sounds. The onboard software is remarkably comprehensive and way too complex to fully describe here but the amplifier’s custom integration within the system is very much enhanced by its incorporation into the design.

 

If you like a clear display on your amplifier then this Moon will not disappoint. It’s among the best out there and easily visible from across the room. It can be scrolled through brightness levels or switched off altogether, illuminating only when in use. The remote is excellent in use though I would have liked a slightly better angle of acceptance; then again I always seem to say that. But that volume control is such a tactile joy to use that I seldom used the remote.

As I mentioned, the 600 V2 sounded pretty impressive straight out of the box, voiding the need for a couple of weeks upstairs while running in. Moon itself suggests a run-in period of 400 hours, which seems lengthy but realistic, but you’ll certainly enjoy the amplifier a lot while it’s getting there.

There is something about high quality integrated audio components like amplifiers and CD players. The best of them have a sense of musical togetherness and perhaps unsurprisingly, integrity that is hard to describe, but within quality designs like this Moon, it’s there alright. I have often heard stereo power amplifiers compared to their mono brothers and while the twin-box designs usually boast better separation, tighter bass, and cleaner power delivery, they often don’t sound quite as musically ‘together’ as their single-boxed siblings. Despite the fact that this is essentially a pair of mono amplifiers in a single chassis. This is something that the Moon achieves supremely well. It’s as if its musical focus is able to employ its 125 watts with precision but sounds remarkably focussed and explicit across its whole bandwidth.

After a few weeks, the amplifier had really come together musically and I think it may well continue to refine its delivery further as the months pass. It seems entirely at home within the system and is quite exceptional in many areas. Its sense of the stereo mix is striking. The way that different amplifiers project the music into the room through the speakers has always fascinated me. The Moon has a tall, wide, and deep take on matters, with emphasis on the ‘wide’.

At any level, the 600i V2 sounds precise but never clinical and has power in abundance. It can swing a bass transient into the Duettes with huge impact and great recovery but it is extremely tonally refined, too. It never grows flustered or stressed, regardless of how much pressure the music puts it under. It walks that line between smoothness and excitement extremely well, due in no small way to its exceptional tonal balance. It’s a chameleon of an amplifier that can sound broad, lush, and tonally rich at one moment and then become a punching, clenched fist, capable of driving the music with great power, tightness and tension the next. This is just one of the things that make it such a great all-rounder.

 

This single-box Moon integrated is a very fine amplifier indeed that can punch way above its weight. When I look at the alternatives, many costing considerably more, I am very impressed with its potential and can imagine it being entirely suitable in systems that may well be conventionally considered a step too far up the performance ladder. After having lived with it for a while I know that to be wrong. It’s hardly cheap but it offers seriously involving performance, comparable with amplifiers costing twice as much. Check out a fully run-in example and I think you’ll agree. The Moon 600i V2 is a great, exceptionally capable integrated amplifier.

TECHNICAL SPECIFICATIONS

  • Type: Integrated amplifier
  • Configuration: Fully balanced, dual mono
  • Inputs: 4 pairs (RCA) Each fully configurable
  • Power: 125 watts – 8 ohms
    250 watts – 4 ohms
  • Input impedance: 23,700 ohms
  • Input sensitivity: 490mv–6v RMS
  • Gain: 37 dB
  • Freq. response: 10Hz–100kHz
  • Gain control: M-eVol2
  • Remote control: All aluminium full-function
  • Display: 8 character dot matrix led
  • Dimensions: 4.0 ×18.75 ×18.1cm (H×W×D)
  • Weight: 21 kg – shipping
  • Price: £7,300

Manufacturer: Simaudio

URL: simaudio.com

Distributed by: Renaissance Audio

URL: renaissanceaudio.co.uk

Tel: +44(0)131 555 3922

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Monitor Audio Studio stand-mount loudspeaker

Studio, by Monitor Audio, is a one-off design by the company, one of the last to spring from the pen (well, the pen on the tablet of the CAD/CAM computer) of Dean Hartley, who stood down as technical grand fromage of the company earlier this year. The Studio is not intended to be a part of a range, nor is it intended to replace any of the company’s Bronze, Silver, Gold, or Platinum models; it’s a purely standalone project, although one that has more than a little bit of flagship PL500-II loudspeaker in its DNA.

The name ‘Studio’ itself harks back to a long-discontinued top of the Monitor Audio tree, although about the only things this loudspeaker has in common with that old range-topper is the name and the use of metal as a diaphragm material in all its drive units. The Studio, 2018-style is a far more down-to-earth model, set in a classic D’Appolito or MTM (mid-treble-mid) design, in line with the central section of the present PL500-II flagship. Of course, that is a cost-no-object, heavyweight multi-driver tower design, and the Studio is a slimline stand-mount that gets you change from a grand.

Most importantly, what it takes from the PL500-II (and, in fact, all of the Platinum range) is what it calls an MPD or Micro Pleated Diaphragm high-frequency transducer (tweeter). This tweeter uses a pleated aluminium film diaphragm bonded to Kapton. This aluminium is then etched away leaving a resistive trace (akin to those on a PCB), which effectively acts as a voice coil. This diaphragm is then held in place by steel plates, and when an electrical signal passes through the traces, the resultant force makes the diaphragm’s pleats squeeze laterally in a manner akin to an accordion (only much, much smaller). By now, keen-eyed audio enthusiasts will be jumping up and down saying ‘It’s an AMT!’, but they are only part right; the MPD variant made by Monitor Audio uses larger rolls than typical Air Motion Transformer designs, to eliminate frequency nulls up in the 30kHz-40kHz region, and phase shift issues in the audio band. Monitor Audio gives credit to Oskar Heil for the original AMT design but thinks its MPD variant improves upon the original.

Coupled with that Platinum Series driver are a pair of 100mm RDT II mid-bass units, bolted to the rear panel. These are also taken directly from the centre of the flagship PL500-II.  First seen in 2016, this hybrid diaphragm features a C-CAM aluminium/magnesium cone front skin bonded to a central core of Nomex, finally with a rear skin of carbon fibre. This sandwich construction is – according to Monitor Audio – ‘just like a perfect piston’ in that it is very light, yet very rigid and very strong. Monitor Audio has been developing hybrid cones for many years, and this is perhaps the company’s lowest distortion model to date.

Even the cabinet has elements of the PL500-II central section in its design, with its curved, elongated figure-of-eight front baffle section, although this is a far cry from the more complex raised and scooped shape of the flagship’s centre section. The cabinet itself is a relatively standard, if tall, rectangular box, albeit finished in satin black, white, or grey to give it that studio appeal. It also features twin HiVe II flow-tuned ports, top and bottom, to give the symmetrical layout of the loudspeakers an equally symmetrical port output. In between these two letterbox ports is a single set of beefy, custom-made rhodium plated terminals, designed to accept spades, 4mm plugs, and bare wires. A matching pair of stands are available and – because the Studio’s footprint is relatively narrow compared to most stands – are recommended. Even at £350.

 

The difficulty a comparatively new Monitor Audio product has to face – especially one that sits outside of the standard ranges – is inertia. People over the years have come to love what the standard ranges do, and often look to more of the same, so when something comes along that does the same things differently, the reactions are mixed. And the Studio lives up to the name – it’s a very resolving studio monitor-style loudspeaker that would not look or sound out of place sitting atop a mixing desk. If you view your speakers to add that little bit of warmth, smoothness, or richness, look elsewhere. The Studio is all about speed, detail retrieval, precision, and focus. It also has surprisingly good bass given the size of the cabinet and the drive units.

It’s not just about the bedroom DJ or home studio market – although the Studio does fit these markets almost unfeasibly well – it’s about those who want to hear the bare-faced truth about their music, in a way that one doesn’t usually expect at anything near this price. That might be something of a double-edged sword (the electronics the Studio is likely to partner and the musical material it is expected to be fed is unlikely to be carefully massaged audiophile-grade stuff, and the Studio will lay those limitations bare). But coming from the high-end on down, many will see the Studio as an inherently ‘right’ – if uncompromising – transducer in the Magico vein. Which means that those wanting a pair of Magicos that have neither the room nor the depth of wallet to own them now have something with a broadly similar sonic performance at an affordable price. It’s strange, but this is more likely to attract new customers/listeners than those from the existing Monitor Audio market.

That’s missing the point; the Studio is all about detail retrieval. If a guitarist uses a phaser pedal and they meant to use a flanger (one of the differences between the sound of Jimi Hendrix’ and David Gilmore’s FX-laden sounds) you will hear the mistake effortlessly.  If a singer needs a spot of AutoTune, you’ll quickly learn to recognise its processing engine’s sonic signature, even at subtle levels. Want to know if that was an alto sax playing low or tenor sax playing high? The Studio will let you into the mix. This is standard fare for more high-end designs, but something of a rarity in the £1,000 price range. Normally, at this point, you either get something effortlessly musical, but not very revealing, or a loudspeaker that equates ‘detail’ with ‘high-frequency energy’ and the Monitor Audio Studio is one of the rare exceptions to both. It does the detail thing well, without falling into the brightness trap, but it doesn’t fall into the other great pitfall of trying to sound a little bit too ‘nice’ in the process. The Studio is meant to be revealing.

The surprising part of the Studio’s sound is the depth of it. There shouldn’t be this much bass coming out of this small a loudspeaker. I played some nasty old school dub through the Studio – the title track from King Tubby Meets Rockers Uptown[Clocktower] – and OK, while it didn’t have the teeth-loosening bass I once heard from a sound system at the Notting Hill Carnival a few years back, but the level and precision of bass coming out of these, that deep bass-line wasn’t lost in depth, weight, or intensity. Full-range it is not, but it is still deeper and more honest in the bass than a speaker this small has any right to be. The speed of the Studio was also clear from those rim-shots and the detail let you hear the truly dreadful quality of the echo (which paradoxically kind of makes the track). This is the kind of track that needs the loudspeaker to start and stop almost instantly because there is so much being fed through the reverb and echo, and these need to be very clearly delineated, and the Studio does this exceptionally well, making most loudspeakers sound sluggish by comparison.

This is more than the speed of attack, though; the Studio also preserves the harmonic structure of that sound. In fact, it’s a lot better at unveiling the harmonic structure of more sensitively recorded music (dub is great but was never recorded for its audiophile qualities). And you don’t get much more harmonic than Cannonball Adderley on his legendary Somethin’ Else album [Blue Note]. Here, the richness of his playing (especially through a CD made before the late Rudy Van Gelder took to remastering his own recordings in his twilight years) comes through well, with the sax soaring away into the upper registers, the underpinning of the piano, and the overall focus of the sound extremely beguiling. Add to that a very precise image, with instruments easy to place and position within a surprisingly large soundstage, and it’s clear the Studio punches above its weight. But most of all, it’s that midrange clarity that is most seductive; the speaker simply draws you into the mix, unobtrusively and uninterrupted. It’s a very transparent presentation that befits the name. And similarly befitting the name, it’s more about detail retrieval than dynamic range. The dynamics are ‘good’ (especially the micro-dynamics and that way of resolving small musical details in the midst of lots of musical ‘goings on’) but don’t expect musical fireworks to be overstated. This is not an over-refinement, but a part of the Studio ethos, because dynamics are often something to be tamed in the studio.

The downside to the Studios is they are demanding of installation and equipment partners. The comprehensively-languaged manual limits the instructions to three feet from the side walls, eight-to-eighteen inches from the rear wall, and six to ten feet apart, with a proviso about experimenting with toe-in, and a hundred-hour run-in. It makes almost no recommendations about electronics and speaker cables. That will get you a sound that is detailed and – if you get them the right distance from the rear wall – with good bass, but musically soulless and undynamic. Throw some good electronics at them (this doesn’t need to be a power-house, I used the Sugden Sapphire pre/power amp combination tested in issue 158), some really good cable (The Chord Company is your friend here!), and approached the installation with the kind of OCD intensity. In return, the Studio eventually unveiled the more dynamic, more expressive, and more passionate performer inside the boxes.

 

The Monitor Audio Studio doesn’t re-write the rulebook, it doesn’t change the laws of physics (Cap’n), and it doesn’t spell the death-knell for the rest of the Monitor Audio range. Instead, it’s a worthwhile addition to that portfolio, more than living up to its name with an incredibly detailed performance in the near-field that is hugely reminiscent of the sound of the control room. It might not be for everyone, but if more recordings were mastered through these loudspeakers, we’d have better recordings!

A studio speaker rarely needs to be dynamic (dynamic range is never an issue that close to the original instrument) and the Studio reflects that up to a point, but careful installation and partnering can expand the perceived dynamic envelope considerably. If you look to loudspeakers as providing a window on the recording, the Monitor Audio Studio is one of the cleanest windows you can get for the money.

TECHNICAL SPECIFICATIONS

Type: Two-way, rear ported stand-mount loudspeaker

Drive unit complement: 1×MPD high-frequency transducer, 2×100mm RDT II midbass driver

Frequency response: 48Hz–60kHz

Crossover frequencies: 2.7kHz

Sensitivity: 86dB SPL (2.83V/1m)

Nominal Impedance: 4Ω

Minimum Impedance: 2.9Ω at 3.5kHz

Maximum SPL: 110dBA (pair)

Amplifier power handling:40–100W

Finish: Satin White, Satin Black, Satin Grey

Dimensions (H×W×D): 34 ×15.6 ×36cm

Weight: 7.58kg each

Price: £999 per pair (stands £350)

Manufactured by: Monitor Audio

URL: monitoraudio.com

Tel: +44(0)1268 740580

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