Begin typing your search above and press return to search. Press Esc to cancel.

Manley Labs Stingray II integrated amplifier

As there are still no tube-friendly speakers chez Kennedy I hooked the Stingray II up to PMC twenty5.26i floorstanders, these aren’t particularly efficient at 87dB but have proved to be well suited to low powered amps like this in the past. That said I did stick with the Stingray II’s ultra-linear operation because the actual 18W isn’t quite enough, to get a good result with that sort of power you’d need a 90dB+ sensitivity speaker with an easy load. As it was I needed to pull the PMC’s away from the wall because the amplifier has less grip in the bass than the high powered solid state amp generally used. The sound remained softer and warmer but the bass was tuneful and adequately controlled, it will come as no surprise to hear that this isn’t really a headbanger’s amplifier, it’s primarily for music lovers looking for an effortless way to enjoy their tunes.

A job the Stingray II does with considerable charm and transparency where it counts, by which I mean the mids and highs which are the clear strongpoints and make everything played sound that little bit better than usual. Abdullah Ibrahim’s piano on Africa, Tears and Laughter [Enja] is full of character, the way that he strikes the keys is very distinctive and hard, making the instrument sound older than it is and the Manley makes this very clear. It also makes the harmonised saxophones sound glorious, their tonal radiance in full effect with none of the glare that many amps add to the mix. Timbre, the specific tonal character of each voice and instrument, is superbly rendered here and this brings out the feeling in every performance rather well. Lest that make it sound like it’s lush and rose-tinted it’s worth mentioning that small differences in recordings are easy to perceive, I played two versions of ‘Gimme Shelter’ [The Rolling Stones, Let It Bleed, Decca] each with a different sample rate, the 176kHz version proving to be more open and clean than the 88kHz, yet somehow the more grungy sound of the latter seemed more correct. I also found a few versions of the Small Faces’ ‘Tin Soldier’, the first of which [Small Faces, Weton-Wesgram] seemed thin and bright, while the Singles Collection [Essential] had forward cymbals but the voice was massive. The winner, however, was from There are but four Small Faces [Immediate], which is fatter and fuller with the keyboards more in evidence and Steve Marriott’s phenomenal voice in the left channel.

Whatever you play though there is a fluidity to the sound that makes it extremely compelling, the Stingray II makes a lot of amplifiers sound mechanical, as if they are having to go through more processes to deliver the music. The limited power means that dynamics are limited of course but any compression sounds entirely natural, the absence of hard clipping is a fundamental part of what makes tubes appealing. It even makes them sound more powerful than they are. Sticking on this technology’s natural partner, vinyl, was an absolute blast and anything with a groove made it very hard to sit still and impossible not to grin. What more can you ask of a piece of audio electronics than to enhance the joy of music in the home? I know that music is a serious affair for many but we’re in it for the emotional connection and this funky amp is rather good at that.

Meet Your Maker: Robert Koch of Robert Koda

Originally from South Africa, Robert Koch now lives in Japan and his amplifiers are both made in Japan and realise many of the best aspects of ultra-specialist Japanese audio electronics. Perhaps more importantly, however, high-performance audio has been a passion for Robert from a very young age. We spoke to him about how he created Robert Koda and where the company goes from here…


How did you start out in audio?

Our family home had two music rooms, both with decent kit. By the time I was 12 or so audio quality became important to me. With the interest in audio came an interest in electronics and radio. I became a licensed radio ham as soon as legally able at 16 years old. Through the club, I was able to get a hold of plenty of technical information but as it happened our city library had all the AES (Audio Engineering Society) journals. A golden find leaving me immersed for days on end, and building huge files stacked with photocopies.


What was your first big break?

As a youngster, I was approached by a chap who wanted me to build him an Audio Research M300. I turned his offer down, but he gave me an after-school and weekend job at his high-end audio store. I spent a decade or so at that store and we were always looking for the “Holy Grail”.

My other big break was to meet Kondo San (Kondo Hiroyasu of Audio Note fame, who died in early 2006) who was kind enough to take me under his wing. I remain incredibly thankful for the opportunity and care Kondo San – and later Ashizawa San – gave me.


What did you learn from working with Kondo San?

Perseverance and patience first. Materials and technique second. Then perseverance and patience again – Completing the task you set out upon without any loss of interest or focus.


Is this why your amplifiers use both valves and solid-state as a base?

As a teenager I learned how tubes work before learning about transistors. I have always loved tubes, but I have come to better understand their inherent limitations and fields of usefulness. On the other hand, I have learned how to better harness semi-conductors in such a way that mitigates their (mostly) soluble flaws. So, it’s a natural flow to follow what can lead to the desired result.


Your products are minimalist yet use balanced and single-ended inputs and outputs. Why?

A pre-amplifier needs to be useful in a number of settings. Some power amplifiers are best run with a single-ended input, others not. The same goes for source components. If there is no or at least very little sacrifice a pre-amplifier should be able to support all these conditions unless specified for a particular niche. In the case of K-15 there is no sacrifice but there is added cost since in our application at least the volume control becomes twice the monster…


Why are your preamplifiers low gain?

It’s all in the pursuit of ‘the purest signal path’! I tried passive pre-amps and found that even though greater voltage gain was not required to achieve a desirable listening volume, there was a definite collapse in sound quality as compared to a decent active pre-amp. Our pre-amps are built with sufficient gain (x2.5) to reach suitable volume even on older digital mastering, and our pre-amps offer loads of power gain. For example, the K-15 might consume 80µW from the source while delivering 27,000µW into a load.


What is the secret to your amplifiers’ absence of sonic signature?

“Dynamic simplicity” is a strong theme and key word in our designs. Music is in a constant state of flux and in order not to displace this delicate time and amplitude relationship we need inherently stable electronics that does not introduce additional moving parameters. Every aspect of the design needs to be ‘sorted.’ For example, a Class A/B output stage would place a music/loudspeaker related shifting load on the power supply and if the power supply was imperfect, time shifted voltage fluctuations could influence other parts of the amplifier resulting in a corrupted outcome… Quite the opposite of our vision of “Dynamic simplicity”.


Robert Koda K-15 EX review

Back to Home


Robert Koda K-15 EX line preamplifier

What do these demands mean in real-world terms (although at this level of audio, the ‘real-world’ is a long way down)? They mean a potential complete re-think of both your system and how you listen to it, and potentially even the music itself. That last could seem worrying, like creating a filter that only plays some music and renders a lot of sounds functionally unlistenable, but actually, it’s more about the volume levels you are used to playing. Often, even the best systems trade dynamic range for headroom, and we have become used to that trade-off. And when faced with one of the rare designs that go in the other direction, it means you might not want to end up playing music at ear-splitting levels, enjoying the scale of music rather than simply its intensity. If that sounds like a compromise too far, it won’t once you hear what the K-15 EX is capable of in terms of that scale reproduction.

A big function in this preamplifier’s uncompromised stance toward equipment selection is its gain structure. This is not a high-gain preamplifier. In fact, it is closer to a passive preamplifier that brought just enough gain along to wake up sensitive amplifiers and drive reasonable cable lengths. As Robert Koch says, it delivers lots of power gain, but that dictates the choice of the power amplifier; less ‘brute force’ more ‘high-performance lower power’.

Robert Koda K-15 EX
This is the sum total of control surfaces on the K-15 EX. It’s all you need!

Perhaps a mark of its importance, the K-15 EX is one of those rare products where there was something of a clamouring of writers wanting to get hold of this. Once it was announced, a steady stream of requests to review the product arrived, sadly at about the same time as I had already finished up with the listening. While I’m not one to play the ‘rank has its privileges’ card too often, this was something I just could not turn down! But this is almost a once-in-a-lifetime offer given the rarity of the K-15 EX. That rarity is not just because of its cost, but because Robert Koda’s production capabilities are extremely limited and the products are basically built to order. And the K-15 EX is perhaps the easiest for Robert Koda to produce; the MC-One is a much longer build and K-160 is even more labour-intensive. Just a handful of preamps will be built each year along with two or three pairs of power amps. While, “so, get in line” seems inappropriate in the context of a £60,000 preamplifier… get in line!

Those few of us fortunate enough to experience the preamplifier quickly realise that it is just that… the preamplifier. Other designs might be excellent signal attenuators, superb and exciting musical creators or profound examples of the electronic engineer’s art. But they aren’t the preamplifier the way the K-15 EX exhibits from the first musical bar.

There are two reviewer’s traps in describing the K-15 EX. The first is to say the phrase, “Zen-like” because it’s so tempting: the Koda comes from Japan and its stillness and mastery over music replay makes you think of those artisan swordsmiths, ceramists, painters and calligraphers. But it’s the wrong thing to do. Zen Buddhism is inherently inward-focused, and those masters were trying to get past their personhood through perfection of a craft, and the craft was almost secondary to that contemplative position. Zen isn’t just Hokusai, it’s staring at a wall for a couple of decades. The parallel and shared experience here is ‘focus’, but where Zen focuses inwards, the Robert Koda is the result of focus on making the best damn preamplifier it’s possible to make by making what’s important as simple and as good as it’s possible to get, and ignoring the rest. If you are looking for a philosophical construct to describe the K-15 EX, try Aristotle: “Nature operates in the shortest way possible.”

That second trap is to try to pin the sound down in musical terms, using pieces of music to highlight specific aspects of the sonic performance. In other words, the big reviewer trap is to try to do your job and describe ‘how it sounds’. The problem with this is yet more philosophical noodling; it quickly becomes too reductionist. You quickly realise when trying to pin down precisely what the Koda does that you are one of those blind men describing an elephant. The focus you bring to the Robert Koda is your own. If your musical trigger is ‘detail’, you’ll be impressed at the level of detail in your music. If it’s ‘soundstaging’, you’ll start using terms like ‘holographic’. If ‘rhythm’ floats your boat, you’ll be taken by its right, tidy sense of a beat. If you crave a musical presentation that has both space and tranquillity, you’ll start using words like ‘limpid’. And so on.

In fact, what you realise is that any such audio descriptions are pointing at other things. You find yourself describing the performance of the source, the power amplifier, the speaker, the cables, the medium, the recording engineer, even the skills of the guitar tech or the piano tuner long before you latch onto the sonic autograph of the K-15 EX. You also find that those preamplifiers that are supposedly ones that sonically ‘disappear’ often rarely actually live up to expectations. The closest ‘real-world’ parallel is probably a well-produced passive preamplifier, in particular, the current generation of passives that are more than just ‘a pot in a box’. The absence of gain stages do give such devices a taste of what an unsullied audio signal can sound like, but the absence of gain stages also detracts from the tonal and timbral ‘structure’ of the music, which you can only experience when you hear a product that manages to bring along just enough gain to provide musical excellence, but not so much as to swamp that sound. In other words, the K-15 EX.

Everyone in high-end will tell you good preamplifiers are a rare thing. Great preamps can be counted on the fingers of one hand (and, if we’re being really picky, it’s a hand that came off worse in a fight with a threshing machine). Those great preamps balance between a sound that can be ‘lovely’, ‘lively’ or ‘liquid’… picture those three elements like a Venn diagram. Most preamps only hit one of those three targets, or at best focus on one aspect and pay lip service to the others. A few manage to nail two out of three at best. In fairness, many will be comfortable with a sound that delivers a ‘two out of three ain’t bad’ sound because it both fits their system and their requirements. And many of these preamplifiers are truly world-class.

But then there’s the Robert Koda K-15 EX. If you think of that Venn diagram, the K-15 EX’s performance is about as smack in the middle as it’s possible to get right now.

The odd thing about the K-15 EX’s performance is the effect it has on you when you go back to whatever you were used to listening to, more or less irrespective of how good that product was. You can respect its performance and what it is designed to do, but suddenly the shine went off what came before. You hear it in terms of a kind of electronic-y sound or just a little too much warmth maybe it just tries too hard and makes things that bit too legato. The K-15 EX doesn’t do any of those things, and it might take some sonic re-evaluation to get overhearing that fundamentally correct sound.

If listening to the K-15 EX seems to expand to your audio brain in a manner that a steady diet of Beethoven does to your musical brain, or reading a lot of Aristotle and Kant seems to do for your reasoning, the process is reversible; the removal and continued absence of the K-15 EX doesn’t just come with a profound sense of loss; the effect is compounded by something close to a loss of a sense. Your musical ‘proprioception’ is reduced by not having the K-15 EX and listening to music takes a big hit as a result. We unconsciously identify sonic performance into ‘live’, ‘good sound’, and ‘clock radio’ grades (with some considerable amount of overlap between the last two). The K-15 EX simply provides more granularity between ‘live’ and ‘good sound’ and the insight that creates is ‘difficult’ to achieve elsewhere (which is the polite way of saying “I’ve not heard anything that gets this close to the real deal since I spent some time with the Audio Note Ongaku back in 1991”). And it’s taking that step closer to the real sound that is both so heady and so difficult to give up.

Shunyata Research Omega QR-s power cord and DF-SS cable elevators

This also comes with a marked increase in soundstage size and solidity. Instruments have their own three-dimensional space marked out in many systems, and often that comes with a sense of being rooted to the floor, but here that doesn’t just take on a three-dimensionality; it gains a visceral, physical presence that’s almost unnerving. Playing Mozart: Piano Concerto No 23 in A [Momo Kodama, Seiji Ozawa, Mito Chamber Orchestra, ECM] and the spacing and the spaces around the orchestra are perfectly portrayed, and the piano is both beautifully rendered and sits in its own rooted position in space more ably than with other cables. It adds to a sense of focus both in audio and musical terms that is sublime.

I expected quiet backgrounds (it’s a Shunyata thing) but they fall away still further than anticipated with Omega QR-s. It’s like even the quietest electronics have more to give, and even the quietest power feed has noise to be removed. Omega QR-s does that brilliantly. Actually, ‘brilliantly’ is not the right word, as there is no additional ‘brilliance’ to the sound. The tonality of the system remains unchanged… Omega QR-s just brings out the best in the kit you have, whatever kit you have.

Shunyata Research DF-SS cable riser

The trio of DF-SS ‘Dark Field Suspension System’ cable elevators act like a little suspension bridge for your Omega QR-s, with the cable resting on a stretchy black polymer between the two towers of each riser. The riser itself is made of a hard black polymer, is mass loaded (you can hear the contents move if you shake it) and has a little set of adhesive feet to stop it from sliding around on a hard floor. The idea is the cable never touches the floor, thereby keeping ground-based vibrational energy at bay. Given the proximity of power cords and speaker cables to loudspeakers and the vibrations loudspeakers can put into the floor around them, this sounds like a sensible idea. And DF-SS is one of those “I kind of wish they didn’t work to keep me sounding credible” devices that damn well ends up doing good. I mean, by the standards of the ‘self-appointed keepers of the hard science’ end of audio, the idea that power cords make a justifiable difference is nonsense, so placing said power cord on cable risers is about as close as it gets to literal nonsense on stilts. I guess me saying they further focus that already focused sound of QR-5 enough to justify their inclusion probably makes me the Mad Hatter. More tea, anyone?

Although there are those who insist on the top of the tree no matter what, in reality, Omega QR-s is the top of the Shunyata tree for everything except Class AB power amps delivering more than about 200 watts per channel. If you are bringing some really heavy amplifier firepower to your listening room, then Omega QR has the extra fortitude you might need. For everything else, QR-s is probably your best bet.


Price and Contact details

Price: £7,500 (C15/C19 socket)


Manufactured by: Shunyata Research



Distributed in the UK by: the Shunyata Distribution company

Tel: +44(0) 330 223 3769


Back to Reviews

Innuos PhoenixNet network switch

What you do see are gold plated tracks, Mundorf caps in the two linear power supplies, Nichicon caps for the switch chip and an OCXO clock right next to it. OCXO clocks are found on a lot of high end DACs because they are among the most accurate available. Also on show are isolating transformers and heavy shielding around the four ports because these ports are prone to sharing any EMI that gets into them. Apparently the sturdy ethernet sockets were selected to work with the substantial plugs found on CAT7 cables which are a lot less flimsy than the plasticky ones on most ethernet.

As the Ansuz X-TC switch that I reviewed last month was in the system when the PhoenixNet arrived it seemed an idea to contrast the two, a contrast that did not do the Innuos any favours to be honest. So I left it in the system for a week and found the results to be increasingly engaging and revealing, when Nuno explained that it takes several days for OCXO clocks to become thermally stable the penny dropped and I went back to comparing it with the Ansuz. This time things were very different, now these two switches were very hard to separate in terms of the sound quality they allowed the rest of the system to deliver. That system consists of a BT router, Airport Express access point, Innuos Zenith SE server, AURALiC ARIES G2.1 streamer and Metronome Le DAC converter. When you add in the fact that I need to connect my PC to the network via the switch you’ll realise that four ports were never going to be enough. In the end I used a Cisco 2960 switch for the router, PC and access point connections and hooked it up to the input on the PhoenixNet.

Innuos PhoenixNet interior
Unlike many network switches, the PhoenixNet uses a power transformer

When I put the Ansuz next to the Innuos a week later things had changed quite markedly, now it was difficult to say which was the more neutral and transparent of the two. They sound different with the Ansuz giving a slightly more three dimensional account of the music albeit one that can seem a little pumped up next to the calmer presentation of the PhoenixNet. The result seems to be the same regardless of where the signal originates, be it from the local server or Qobuz you get the same small variation. It’s the sort of thing that could be tweaked with different feet under the box and made me wonder whether the Ansuz didn’t like the glass shelves of my rack, it has much harder aluminium feet than the well damped ones on the Innuos.

Either way it’s safe to say that the PhoenixNet is a first class network switch, one that allows oodles of detail through and delivers it with a very light touch. I love the way it reveals the quiet notes on Van Morrison’s beautiful ‘You Don’t Pull No Punches, but You Don’t Push The River’ [Veedon Fleece, Warner Bros]. this delicate detail is what makes a good piece of music reach out and touch you. If there is too much noise in the system it gets blurred and some of the magic goes with it, the result with the Innuos in the system is very close to good vinyl replay and with the prices being asked for this album today about as close as I’ll get to enjoying it. Equally critical is the sense of calm that this switch brings to proceedings, this is another result of noise being significantly reduced and takes away an awful lot of the subtle glare that afflicts digital audio. There are plenty of components that soften this by smoothing it out using EQ and other means but that tends to rob the music of its energy and impetus, this switch does it without compromising timing or the definition of leading and trailing edges.

AURALiC Launches Amazon Music Unlimited on All Products

Beaverton, Dec. 17, 2021 – AURALiC Inc., today announced that it will now offer the capability to stream Amazon Music Unlimited on all of its streaming products.

Owners of AURALiC products may now control and play Amazon Music from within Lightning DS, a feature-rich and intuitive control app designed in-house by the AURALiC engineering team. With Amazon Music Unlimited, subscribers can stream more than 75 million lossless, High Definition (HD) songs, with a bit-depth of 16 bits and a sample rate of at least 44.1 kHz (CD quality). Customers can also stream more than 7 million songs in Ultra HD (better than CD quality), with a bit-depth of 24 bits and a sample rate up to 192 kHz, which reveals even more nuances that were once lost in files compressed for digital streaming.



The team at AURALiC continually seeks out new, high-quality music subscription services to integrate with their award-winning product range as part of an ongoing effort to provide customers with as many options as possible when streaming music at the highest levels of quality.

About AURALiC Founded in 2009, AURALiC designs innovative, high-performance audio products focused on getting the most out of your music. Whether stored on a hard drive at home, or streamed to you from an online service, AURALiC products will bring all your music to life.

Contact:EU/UK: Richard Bates, [email protected] 

Russ Andrews RANS-1 Network Switch

My sample came pre-used through the review circuit (we’re not the first to review the RANS-1, and the box it came in free from instructions and was more ad hoc than we’ve come to expect from Russ Andrews), so there was no need for running in and the box was good from the get-go. I used it to connect the Linn Klimax DSM tested in this issue, both to the outside world and to a range of servers (Naim and Melco) during the test. I also compared it with the Melco S100 switch and a baseline Netgear eight-porter. Finally, I compared it to the Network Acoustics ENO filter and used that in and out of the digital chain.

The RANS-1 fared extremely well in all settings, demonstrating a quieter, more controlled sound throughout. Naturally, its biggest differences were heard comparing this to the Netgear baseline switch. This budget device seemed to give the sound a nasality and unsatisfying forward-brightness to the sound that might seem initially ‘clean’ but was ultimately ‘grating’. This applied whether streaming locally or online. Swapping that Netgear box out for the Russ Andrews
RANS-1 switch (with no other changes) was a subtle shift in the right direction, making music more approachable and listenable. It replaced that fake ‘clean’ sound with a sense of balance and musical order.

The results were less clear cut between the Melco and the RANS-1, with the Melco going more for the sheer detail of performance and the Russ Andrews going for a more sonorous and relaxed approach. Both were extremely musical sounding, just musical in different directions. Finally, in the ‘compare and contrast’ part, the ENO filter levelled the playing field somewhat, making all three options less marked in performance boosts. Nevertheless, the combination of ENO+RANS-1 works extremely well… and sounds like a German experimental album title from the 1970s.

Russ Andrews RANS-1
A Kimber Kable joins the two sections of the switch

Taken on its own, the Russ Andrews RANS-1 really does demonstrate just why the audiophile network switch is a viable product in today’s audio. It’s a subtle performer, gently and quietly improving the lot of streamed audio by making it sound more ‘human’. Backgrounds are distinctly quieter, the treble is more refined and less harsh and forced sounding. There’s a sweetness and ease to the sound, but it’s one with a gently-focused sense of rhythm too. In a medium that is often accused of being loud and shouty at times, the RANS-1 shows it’s possible to be deft and delicate, without being ‘flaky’ sounding.

In truth, I’ve been sort of avoiding the whole audiophile switch due to my own digital preconceptions. Packetised data should be unfazed by its transfer through a network, but the RANS-1 makes a convincing argument that there’s more to the topic than it first appears. This is a true eye-opener.



  • Type: Network Switch with external power supply
  • Ports: 8 RJ45 gigabit ethernet ports with additional shielding and damping
  • Clock: internal re-clocking with custom made Trichord unit
  • Internal wiring: Kimber Kable
    Russ Andrews 0.3m DC link cable made with Kimber PBJ and locking connectors
    4mm grounding socket
  • Casing: Custom, matching ABS cases
  • Dimensions (W×H×D): 187 × 47 × 130mm per unit
  • Price: £956.50

Manufacturer: Russ Andrews


Tel: +44(0)1539 797300

Back to reviews

REL Serie T/7x subwoofer

Set-up remains the same for audio purposes; use the Speakon cable and high-level input, with the cables connected to the left and right positive and a single negative terminal of your power amplifier. Now use a vocal recording and dial the subwoofer down until it is just past audibility. Then confirm with a record with good bass; you can combine the two if you use ‘Ballad of the Runaway Horse’ by Rob Wasserman and Jennifer Warnes [Duets, Universal]. Now come back a week later and turn it down a notch, then make a cup of tea or coffee, sit back down to your system, and be a bit amazed!

So far, so REL. What the T/7x does is introduce some extra speed and weight to the bass, the sort of performance normally expected from more upmarket models in the line. Weight here is a difficult subject because the Serie T/7x does not make a small speaker seem ‘weightier’, just ‘bigger’ and more importantly ‘better’ across the midrange. I used this in particular with the Rogers LS3/5A SE tested in this issue and this proved to be both an ideal test subject and an ideal candidate for the Serie T/7x. The REL added depth to the sound, but not in the way that it changed the tonality of this well-known speaker system; more that it filled in the bottom end in the same way the SE version fills in the midrange over the original; thoroughly, but paradoxically almost imperceptibly.. The REL was fast enough to pass the Trentemøller test [‘Chameleon’, The Last Resort, Poker Flat] and provided enough reinforcement to make out a few more left-hand piano notes on the Liszt B-minor Piano Sonata played by Martha Argerich’s during her Début Recital {DG], but more importantly on this recording, it also gave that recording the sense of space and gravitas needed to make it something truly outstanding. Switch the sub off and seemingly not a lot happens to the sound, but the sound also collapses and becomes insubstantial. Put it back in and the bass is not overt or oppressive, in fact, it’s almost not there, but the way the T/7x delivers that ‘almost not there’ bass makes all the difference. And, if you compare that bass delivery to previous REL designs under about £1,500, the new T/7x has both more substance and form and less intrusion into the sound of the speakers.

REL Serie T/7x rear panel
The REL controls are easy to navigate

The speed of the Serie T/7x is an outstanding feature. Few do bass depth and bass speed like this subwoofer at anything like the same price, and for that alone it deserves very high praise because that means the REL sub can keep up with fast musical transients played through equally fast and reactive loudspeakers. Couple that with the sort of depth to fill out floorstanders in this category and it’s an exciting addition to the audio canon.

While we aren’t geared up for home cinema here, it must be noted that the REL Serie T/7x is not just for us music lovers. When used as a bass channel instead of bass reinforcement, it has the sharp transient response and directness that makes it so good for two-channel, but with more of an oomph needed to resolve what home cinema does so well. In fact, I’d argue that where previous REL subs at this price point were hi-fi subs that could be used in cinema, the Serie T/7x straddles the divide almost perfectly; home cinema enthusiasts will view this as a powerful sub that can also do two-channel music, where two-channel enthusiasts see this as the audiophile’s friend that can also speak cinema.

In audio settings, a good subwoofer should be seen and not heard like a Victorian schoolchild. REL has consistently been one of the few subwoofer brands to achieve that goal, and the REL Serie T/7x does it better than before. No, it’s not going to out-do a No. 25 or the big 212/SX from the brand, but it does draw heavily from the S/510. While in absolute terms, the S/510 is a better sub all round, the gap has closed significantly. The Serie T/7x at £999 throws down a gauntlet to other subwoofers. It’s the one to beat right now.



  • Type: Front-firing active woofer, down-firing passive radiator
  • Inputs: Hi Level Neutrik Speakon, Lo Level single phono, LFE phono
  • Active drive unit: FibreAlloy™, 200mm long-throw, inverted alloy dust cap, steel chassis
  • Passive radiator unit: 254mm long-throw, inverted dust cap
  • Power output: 200w (RMS)
  • Lower frequency response: 31Hz at -6dB
  • Gain control range: 80dB
  • Dimensions (W×H×D): 36 × 32  ×36cm
  • Weight: 17.5kg
  • Price: £999


Manufactured by: REL Acoustics


Tel: +44(0)1656 768777

Back to Reviews

Enleum AMP-23R integrated amplifier

The odd arrangement of feet on this amp was arrived at by calculating the exact centre of mass of the amplifier by weighing every component and the chassis so that it’s supported in a balanced fashion. The feet themselves have a loose base that’s designed to provide isolation, these metal bases are very slippery however and Enleum provides silicone discs to put between amp and support surface to stop it sliding. Not that this is likely to be an issue unless you put heavy cables in the back, operation is largely achieved with a compact remote handset that provides a few other features such as mute.

The obvious drawback with a 25 Watt amplifier is that you really need high sensitivity loudspeakers to play music at entertaining levels, 90dB at the full 1w/1m (rather than the misleading 2.83V/1m) is about minimum unless you sit very close or listen at low levels. I don’t actually have such a speaker in my usual armoury but took advantage of some JBL HDI-3800s that were in for review, these are substantial beasts with three 8 inch bass drivers and a compression driver tweeter but they offer a 92dB (2.83V/1m) four Ohm load, which is equivalent to 89dB at eight Ohms, so that’s how listening commenced.

Enleum AMP-23R internals
Small, but beautifully formed, the internal architecture of the AMP-23R is complex.

Actually, I tell a lie, as I had PMC’s mighty (and mighty hard to move) Fenestria loudspeakers in the system when the Enleum dropped I thought what the heck and hooked it up. Given the phenomenal resolution of these speakers and the relatively low sensitivity of transmission lines, the results were remarkably good with excellent delicacy through the midband and decent weight and body to bass guitar. Not Bryston 4B3 (300W) weight and body but enough to really enjoy the poise of Carla Bley’s Life Goes On [ECM] where the playing from bass, piano and sax came across in nimble and charming fashion. I also tried a dem favourite in London Grammar’s ‘Hey Now’ [If You Wait, Metal & Dust], here it was the vocal that really shone alongside the precise nature of the effects used to make it work so well. Even the low end on this was respectable, not floor-shaking but muscular. It reveals that 25W can do a lot more than expected when backed by a decent power supply.

I managed to move the Fenestria in the end and brought things down to a more sensible level with the aforementioned JBLs. These probably need an amplifier with more grip than the Enleum but produced some delicious low end with a number of tracks. The emphasis however is more on timing, texture and the many qualities of musical composition, this amp proved to be exceptionally good at revealing what makes a piece of music appealing. There is a tendency when reviewing to play the first two or three minutes of reference tracks and move on, here that proved almost impossible because the music was so captivating that I had to let it run to the end and often onto the next piece. It’s hard to say exactly how this amplifier achieves this but it clearly has a degree of musicality and charm that eludes a lot of the competition. Low power may have something to do with it and the fact that similarly equipped valve amplifiers can sometimes do the same trick would back this up, but that’s not all. I suspect that the simplicity of circuit and short signal paths are important, that and the fact that it runs so hot, those optional $500/£500 feet aren’t tall for style points, they allow plenty of air to circulate around a box that uses its small case alone to dissipate heat. In fact, the primary goal of the feet is as a vibration and resonance control device, but help as an additional heatsink or heat dissipation device.

I decided to try the AMP-23R with something closer to its own size in the form of PMC twenty5.21 stand-mounts, these aren’t particularly efficient but have a relatively easy load. This combination proved to be addictive, both components have a degree of coherence that’s astonishing and makes the music totally immersive, not to say emotionally overwhelming at times. I tried an old (usually vinyl) favourite in Crosby, Stills and Nash’s ‘Helplessly Hoping’ [Crosby, Stills and Nash, Atlantic] on the Melco N50 and iFi Pro DSD and was blown away by the beauty of the harmonies. Digital transfers of analogue rarely achieve a connection that’s this powerful, and all from a system that would fit in a suitcase. Haydn string quartets were wonderfully spirited, full of refined energy and verve while Radiohead’s oft monochrome ‘Decks Dark’ (A Moon Shaped Pool, XL) revealed tonal colours that are rarely glimpsed. Even Kendrick Lamarr’s ‘How Much a Dollar Cost’ [To Pimp a Butterfly, Interscope)]proved unputdownable thanks to a level of lyrical intelligibility that allows the message behind the song to come across so clearly.

Lindemann Musicbook Source II and Power II

From the Lindemann press release

Following the recently announced Musicbook POWER II, the Musicbook SOURCE is now available from LINDEMANN in its second generation as well. Both models have been carefully revised and now, as a team, offer even more musical information together with an amazing sense for timing and interplay. Sound quality at the limits of technical feasibility! 

Important to know: despite considerable bottlenecks of the electronics market LINDEMANN continues to manufacture the musicbooks in series. The production is secured for the upcoming years! This works not least owing to 100% made in Germany. 


In its current version, the Musicbook POWER II has become some kind of hybrid amplifier: The voltage amplification is largely provided by an ultra quality analogue J-FET gain stage; the adaptation to the speakers is handled by proven N-Core circuit technology which is used as a power buffer. The result is impressive: sparkling verve and a wealth of detail, combined with total control over the loudspeaker. 

Prices: Musicbook POWER II 500 = EUR 2,690.– / Musicbook POWER II 1000 = 3,590.– 


Likewise, the Musicbook SOURCE II has been systematically developed further – with a focus on the analogue preamp. The headphone output sounds even better now and can also drive 16-ohm headphones. 

Even more effort was put by LINDEMANN into the further development of the firmware where initial bug fixes and patches have finally turned into a completely new stack. The most important novelties are the implementation of Spotify Connect and TIDAL Connect. Moreover, there are minor and major new features such as the elimination of the lipsync problem when connecting a TV set, network standby, fixed-level line output with analogue volume control bypass, dB-linear volume control in 80 incremental steps, sampling rate display for the digital inputs, Spotify selection via remote control without using the app and many others. 

Lindemann Musicbook Source II
Lindemann’s latest preamplifier in the Musicbook line: Source II

Owing to 1-bit re-sampling, the great-sounding AKM converter modules and the upgraded preamp, the new Musicbook SOURCE II once again raises the sound benchmark for the best streaming DACs. By the way: despite worldwide supply shortages LINDEMANN will also in the future relies on the probably best converter modules from AKM and the already legendary 1-bit re-sampling process for the SOURCE II! 

Prices: Musicbook SOURCE II = EUR 3,590.– / Musicbook SOURCE II CD = 3,890.— 


As you may well expect from LINDEMANN, “ancient“ models – as far as possible – can always be kept up to date. Since early November existing users of the Limetree BRIDGE, Limetree NETWORK and Musicbook SOURCE I models can also enjoy almost all features of the SOURCE II with a general and, as usual, free firmware update (if not already present)! 

For more information see 


Back to News

Rogers LS3/5A SE stand-mount loudspeakers

To maximise benefit without ending up with a loudspeaker that costs significantly more than the base model, only the front baffle of the LS3/5A SE is made from Panzerholtz. This also facilitated an investigation into what benefits the last half century of electronic engineering might have on the crossover network, and the R1 and R2 resistors in the crossover are of a higher grade (but the same values) than the BBC circuit specifies. Such is Rogers commitment to the LS3/5A, however, that everything else remains identical to the specifications laid down more than half a century ago. And if you want absolutely identical to the original – right down to recreating something close to the original Gold Badge of mid-70s Rogers speakers – you can get that too.

The SE invites a bit of a musical conundrum though. The Keepers of the Flame will likely reject the SE version without ever listening to it. Those who want a LS3/5A because they have heard it can sound good will –hands down – prefer the SE in a straight comparison. It does everything the LS3/5A does, but with a little more pep in its step. Dynamic range is wider, soundstaging is deeper and more open, the sound is lither and music flows effortlessly, and the overall sound has a bit more of a rhythm to it. Those who think the piano tone of a LS3/5A is sweeter than the real thing will find the SE is more like an actual piano. And yet, all of these changes do not undermine the basic LS3/5A presentation; speech is still world-class, and that more accurate piano sound just sounds more like it gave up artificial sweeteners.

One of the big changes sonically is in terms of soundstage size and the ability for the loudspeaker to ‘disappear’ in the room. Typically, the smaller a loudspeaker gets, the closer it gets to a point source, making for superior soundstage properties. The LS3/5A has long had that advantage so it’s soundstaging was never less than ‘excellent’, but the SE version makes that soundstage both wider and deeper, and present a more focused ball of sound between and in front of the loudspeakers. This is most telling in the trail off from ‘I Capuleti e i Montecchi’, Act 2: “Tu sola, o mia Giulietta… Deh! tu, bell’anima” from the Stella Di Napoli album by Joyce DiDonato, [Erato]. Gradually the orchestra fades to just her voice and a beautiful bit of French horn playing, and the two ‘instruments’ sit perfectly in a three-dimensional space that just makes the sound that bit more enticing.

Perhaps just as importantly, the SE version makes the LS3/5A start and stop faster. Often typical LS3/5A music programming doesn’t really challenge a loudspeaker’s transient delivery, as a lot of speech and classical music is quite legato in reality. So for this test, it’s best to really push the Rogers loudspeaker to the edge of its comfort zone… ‘Becoming Insane’ from Infected Mushroom’s Vicious Delicious album [World Club Music]. When the fast back-beat kicks in, the speed and precision of the SE responds accordingly. Original LS3/5A models tend to be slightly behind the beat, but because that Panzerholtz front baffle is so inert, the pace of the sound is markedly improved.

The SE doesn’t radically change the LS3/5A. It doesn’t add octaves to the bass, doesn’t make a low-sensitivity design with relatively limited amplifier headroom suddenly become a party loudspeaker… but if it changed these things, it wouldn’t be an LS3/5A, and I’m both aware and conscious that this name game is sailing close to philosophical noodling. The point is, just that relatively simple change to a Panzerholtz front baffle makes the LS3/5A SE a better loudspeaker without undermining what makes the LS3/5A a great speaker to begin with. While that will fall on deaf ears to some, I suspect many will feel this the right balance between ‘preservation’ and ‘performance’.

Finally, there are two parts to this story. The Panzerholtz stands designed for the SE are expensive but are a worthwhile upgrade to any existing LS3/5A. Compared to a pair of old but trusty Kudos S50 stands that have regularly been pressed into service to support BBC loudspeakers, the improvement is astonishing, in a ‘Playtex’ kind of way (it lifts and separates the sound). Vocals – which are the original reason for the LS3/5A’s existence in the first place – are better projected into the room and are even more articulate. Listening to BBC (of course) Radio Four newsreaders and continuity announcers is an acid test of a loudspeaker because they are perhaps the best annunciators around and if you listen regularly, a known source. Even the mildest deviation from fidelity comes through as too much chestiness, slight emphasis on sibilants or even a mild ‘spitchiness’ to the midrange, and the loudspeaker stand ensures those elements are dealt with thoroughly. I think the stand is a mandatory ‘must include’ for LS3/5A owners, whether or not that loudspeaker has a SE suffix. It might also be a ‘must have’ for owners of post-LS3/5A designs like the Spendor Classic 4/5 or the Harbeth P3 ESR, but I didn’t have a pair of either to test.

Line Magnetic LM-512 CA preamp/LM-845 Premium integrated/power amp

The LM-845 Premium is a real gas guzzler of an amplifier built on two chassis, with the main one alone weighing 40 kilos and the ‘smaller’ unit coming it at over 20kg. The latter houses the output transformers, which gives you an idea of the manufacturer’s ambitions and how little the company is prepared to compromise. As you might be able to tell from the array of controls on the front panel, the LM-845 operates as both an integrated amplifier or as a power amp, and there are four line inputs (one on XLR) plus a preamplifier input and a control to choose between operational modes. There’s even a remote handset for volume. The array of knobs and meters on the front would suggest that it’s a measurement device for good reason as it can also measure the bias on the various tubes sprouting from the top.

There is also the option to adjust negative feedback between minimum and maximum. I listened in its full-on mode because that was how it arrived and would lend itself to less sensitive speakers than are generally chosen for 30 Watt amplifiers. However, I gave the minimum feedback option a try and got a more ethereal and soft sound that worked well with classical pieces but less so in situations where rhythm is crucial. The tube array consists of 12AX7 triodes in the input stage, pairs of 310A and 300B drivers, and the eponymous 845 triodes in single-ended mode, providing the loudspeakers’ power. The latter usually looks pretty significant, but on an amplifier of this scale, they don’t seem extreme in the least.The output transformers in the second, Premium, chassis connect to the amp with a pair of chunky umbilical cables, and speaker cabling connects to one of three impedance taps (4, 8 and 16 Ohms) on the back of this unit. Fit and finish are once again excellent, but the styling is more restrained than the main amplifier.

Listening commenced with the 845 Premium as an integrated driving Bowers & Wilkins 802 loudspeakers that are strong on sensitivity if not easy to drive. Still, the pairing worked well, unusually so for a single-ended triode. The critical tube quality of tonal colour was immediately apparent on Arve Henriksen’s trumpet and the atmospheric electronica that surrounds it. There was good depth to the soundstage too, and not too much midrange forwardness. The latter is all too common with SETs when they struggle with a heavy load, but there wasn’t much struggling going on here. I loved the depth of tone it pulled out of the basses on ‘Magnet Pulls Through’ [Tortoise, Thrill Jockey], and the weight behind the kick drum was round and deep. When the snare comes in, you can feel its snap and the pulse of the soundfield produced by the bass, which is tactile music reproduction with lots of nuances. Immediacy is a classic triode characteristic, one of the reasons for this ancient technology’s appeal, and you get plenty of it with the Line Magnetic, which brings Leonard Cohen and Herbie Hancock’s version of ‘The Jungle Line’ to life [River: The Joni Letters, Verve]. The amplifier enhances the gravelly-voiced description of Rousseau’s painting, making the imagery that much more vivid and lush.

Adding the LM-521 CA preamplifier to the system significantly enhanced all-round transparency; the low-level resolution was clearly increased, which meant that even simple pieces of music took on a far stronger sense of realism. One such being ‘Grandma’s Hands’ [Bill Withers, Just as I Am, Sussex], where the voice gains depth and shape as you might expect, but the rhythm section comes into full focus as well, now you can feel the groove as well as follow the tune. The preamplifier brings precision and definition of the quieter elements that, while it’s more revealing, is also beneficial to the musical flow. There often seems to be a trade-off between resolution and musicality, but this pairing brought a balance to these key qualities that were extremely rewarding. Allowing you to play jazz, classical, rock, you name it… and feel emotionally and intellectually involved with every piece.

Voices are a speciality, of course, each one offering up so much of its distinctive flavour when Van Morrison sings ‘Who was that Masked Man’ [Veedon Fleece, Warner Bros]in a falsetto, it strikes you to the core in a way that rarely happens. With more up to date recordings, the effect was equally provoking; the sheer presence of notes in the room giving the music a power to captivate that was inspiring. Out of interest, a pair of PMC twenty5.26i speakers were harnessed to this amplifier; these showed that the 845 Premium is no slouch when it comes to timing, letting the groove shine through on whatever was played.