CH Precision L10 line-stage preamplifier and M10 twin-chassis power amplifier
You might well think we’re getting pretty good at this hi-fi thing. After all, we’ve been at it a while and, reading the press, you could easily conclude that, as the parade of ‘latest, greatest’ products continues to pass, we must be on an inexorable upward trajectory. Surely perfection awaits – just beyond the next rise. Yet perfection – just like tomorrow – seems to be always a day away. With pages to fill and audible differences to report, the distinction between different and better all too often gets blurred. But occasionally – just occasionally – a product arrives that resets your expectations, redefines possibilities and represents a fundamental step-change in performance, that forces a reassessment of our capability and the status quo. You can wait years for such a product: On average I reckon to hear two or three a decade. But then, like London buses used to, you’ll have three roll up at once.
In the last year I’ve been fortunate enough to live with and review the Wadax Atlantis Reference DAC and the PureLow LO sub-woofer, which have completely redefined expectations at opposite ends of the system. Now the CH 10 Series amplification has arrived – and it is everything I hoped and more. If the Wadax and the PureLow have substantially extended my expectations, these new flagship electronics from CH Precision have forced me to completely revise my approach to reviewing, reconsider my methodology and reach for an entirely new descriptive lexicon. They deliver an entirely new level of access and connection to familiar recordings. But beyond their impressive fit and finish, their physical and musical presence and authority, for all their remarkable sonic abilities and musical attributes, what they really provide is just more: more music, more of the time; more involvement across a wider expressive range; more of what hi-fi is supposed to be about. Sometimes products really are simply better – a lot better. This is one of those times.
You could also be forgiven – at least at first glance – for wondering what all the fuss is about. Despite coming in above the established 1 Series and at significantly higher prices, the new amps don’t look that different and, thanks to the modular, multi-configurable, multi-box approach that defines CH’s existing product line, you’re probably used to seeing stacks of near identical boxes in that particular shade of blue-grey. The company has chosen to retain the essential footprint, finish and layout of their existing products – a move that will certainly endear them to 1 Series owners looking to upgrade. If the straight bevel that cuts across the fascia in place of the previous, characteristic curve is enough to differentiate the 10 Series from the existing products, at least for those in the know, the addition of both darker, graphite grey and champagne gold finishes definitely break the mould. Owners even have the ability to mix and match the finishes within a single unit – allowing you to mix a gold front-panel with a graphite chassis. This is hardly an aesthetic free-for-all or the dazzling range of options offered by some manufacturers, but for a company that has spent 10-years relentlessly getting to a point where everything it makes is exactly the same colour, this is definitely letting their hair down! Operationally too, this is a story of evolution rather than revolution. When your existing products already set the standard for user configurable versatility, why change a winning formula? Instead, CH has refined those facilities still further, not in operational terms, but adding significantly to the user’s ability to tune performance to their system and their musical preferences.
Both the L10 and the M10 use essentially the same topology as the equivalent 1 Series units, but circuit boards have been relayed to reduce interference and induced noise, with every component in their fully discrete, balanced and complementary circuit paths re-examined and, wherever possible, upgraded. The L10 (£65,000) is now a two-box design, with a massive, dedicated power supply, stuffed with those proprietary red caps and optimized specifically for its functionality and circuit topology. The same dual-concentric control drives operations, but users now get to select whether the unit operates with or without global feedback – a decision that is both programme and system dependent. The M10 (£83,600) is also a two-box design. That’s right – those two boxes make up a single stereo amp – albeit one that can be reconfigured for various bi-amp or mono output topologies. The separate power supply weighs in at 78kg. Lift the lid and it looks like something out of Chernobyl – although thankfully it’s considerably more stable! The amplifier adds another 53kg (hence the practical necessity to split the boxes), an entirely new input topology and half as much power again as the M1.1 to go with the twice the capacity power supply.
Underlining the evolutionary nature of the 10 Series’ development, the user selectable feedback ratio in the M10 is available in 1% as opposed to the previous 10% steps, a change that offers a really significant increase in the ability to match amp-to-speaker-to-room in any given situation. In the same vein, the unit’s coupling/stacking system has also evolved. Beautifully executed, the new system really works, delivering the expected drop in noise floor with its attendant increases in dynamic range, focus and instrumental colour and harmonics that come with any effective coupling system. But the best thing about both products, at least from this reviewer’s point of view, is that the substantial invoice that arrived with the products didn’t have to be paid! There’s expensive, seriously expensive and then you reach eye-wateringly, pip-squeezingly unaffordable – at least for most of us. Safe in the knowledge that if you can contemplate one M10, then the second probably isn’t that great a stretch, CH even took the opportunity to underline the product’s versatility by including a second amp.
Given the popular belief in the law of diminishing returns, given the fact that the 1 Series have already established themselves as benchmark performers and given the outward similarities between the 10 Series and the more affordable 1 Series (please note the qualifier – I’m not sure anybody would describe the 1 Series as affordable!) I insisted on having the L1/X1 and M1.1 on hand for direct comparison. Such is CH’s confidence in the 10 Series that I also received not just the L1 and M1.1 but the full four-box line-stage and a pair of power amps. On the downside, that’s a lot of boxes and an awful lot of comparative listening. On the upside, it brings a whole new meaning to the phrase “ten tons of fun!”
So, was CH Precision’s confidence in the 10 Series well-founded? Sit the 1 Series alongside the new flagships, take a listen and it will take barely a note to appreciate not just the scale of the difference, but its musical significance too. There are two ways of looking at this: you can simply compare equivalent 1 and 10 Series set-ups – or, you can work up to the 10 Series, one product at a time. For owners of 1 Series, it’s probably those incremental steps that matter, so let’s start there and the obvious place is the L10. Dropping the flagship pre-amp into a system comprising the L1/X1 and a pair of M1.1s quickly demonstrated why CH sent me the four-box L1. The gulf in performance between the two-box 10 Series unit and its 1 Series equivalent was huge, with the sense of clarity, flow, transparency and human agency dramatically more apparent with the L10. Even stepping up to the four-box L1 only narrowed (rather than closed) the gap, the quartet of 1 Series boxes delivering their trademark solid stability, but unable to match the lucid articulation, transparency, ultra low noise floor and fluid musical expression of the L10. Using the Kertesz/VPO New World (Decca) as a benchmark, the L10 delivered a more musically emphatic performance, with more drama, more effective pacing and greater momentum. It wasn’t just that the orchestra sounded more energised, and their instruments were more vivid and natural. They simply sound more here, the sense of purpose and overall direction, the influence of the conductor on the shape and pace of the music far more obvious. Switching scale and genre, with Jackson Browne’s ‘The Road’ (Running On Empty) the L10 demonstrated more natural tonality and diction on vocals, a more expressive and intimate performance. The difference in height between the fiddle and the guitar was more obvious, but also made more sense, adding to the intimacy and putting you inside that hotel room. The mid-track shift to the concert venue extended the acoustic space out beyond the confines of the listening room. Despite the efforts of the engineer to fade from one location to the other, the actual switch was far more clearly defined, adding another layer of insight into the process itself, without pulling the track apart.
Putting that in perspective, in Issue 175 Alan Sircom described the four-box L1 as “one of the finest pre-amps ever made” – and he wasn’t wrong. Not only that, but the four-box L1 actually costs more than a single, two-box L10. Yet in direct comparison, the L10 still succeeds in making the L1 in its ultimate form sound processed and constrained, gated and slightly clumsy! That isn’t to belittle the four-box L1, which remains one of the finest pre-amps we’ve heard. It’s just indicative of how far the L10 has raised the bar. Once you factor the M10 into the equation, the performance gap becomes a yawning chasm. The loudspeakers I used for this review were the Stenheim Alumine 5 Signature and Göbel Divin Noblesse, with and without the PureLow LO sub-woofers. You can bi-amp both speakers, an approach that makes the most of the CH Precision power amps’ configurable in and output topology. That means that, when comparing a pair of M1.1s to a single M10, the 1 Series amps should enjoy a significant advantage, being able to bi-amp as opposed to simply bi-wire the speakers. But despite that, the performance of the single M10 still trumps the pair of M1.1s, delivering greater separation and dimensionality, timbral and textural definition, fluid rhythmic expression and more positive dynamics, all set against a ghostly quiet, jet-black background. Instrumental identities in the opening bars of the New World were far more clearly defined and recognisable, the pacing more explicit, the steps on the staircase leading to the first big crescendo wider and far more clearly delineated in terms of dynamic range and density. The complex patterns and staccato rhythms of Kopatchinskaja/Gabetta’s Les Plaisirs Illuminés are more ordered and intelligible, the instruments more vibrant and the playing more incisive. Add the second M10 and you start to wonder how on earth you were so impressed with the M1.1s? Swap directly from the four-box L1 and a pair of M1.1s to the L10 and M10s and the difference is frankly astonishing. Raising the bar? This is like Sergei Bubka turning up to the 1924 Olympics. And therein lies the challenge. The L1 and M1.1 didn’t stop being great products overnight just because the L10 and M10 appeared. They are still great products. Appreciating the true extent of that performance gap depends on direct, side-by-side comparison – meaning that if you leave the 1 Series alone for a bit and then come back to it, you’ll find it’s recovered its composure – or you’ve forgotten its discomfort. But that doesn’t change the reality that in very real terms, the 10 Series represent a step-change in the performance envelope – a step change that becomes apparent as soon as you listen to them. They have forced me to reconsider the way I think about amplifiers and the way that they work.
In the past, reviewers have always tended to describe amps in terms of what they do: amplifier A has a massive soundstage, amplifier B has incredible detail, but amplifier C – just wait ‘til you hear its bass. It’s almost as if the amps are bringing out or extending attributes in the system’s performance. With the 10 Series, that gets turned on its head. Instead of marvelling at what they do, you suddenly realise what they don’t. Or to put it another way, you realise just how obvious the sticky fingerprints that other electronics smear across the signal really are. What makes the 10 Series special is that absence – the intrusion, the distortion, the compression, the additive colouration and the etching or thickening that they don’t impose on the signal or superimpose on the performance. The 1 Series has always been noted for its uncanny ability to offer low colouration without resorting to the sort of clipped sterility that so often passes for neutrality. But in terms of musical and operational invisibility, the 10 Series is simply in another league – which is exactly what you hear when you place them side-by-side.
If you want to assess an amplifier or system’s ability to stand aside, the acid test is comparing different performances of the same piece. After all, it’s hard to confuse Isaac Stern and Lisa Batiashvili – musically or visually. But in audio terms you can take it a step further still, comparing different pressings or masterings of the same recording. Time and again, the musical distinctions between different pressings of the same, often familiar recording were laid bare: Du Pré’s Elgar Cello concerto in its original CD issue, the SACD, the UHQCD and the live performance on Testament; original and UHQCD issues of Coltrane’s My Favorite Things; Kleiber’s Beethoven 7th on DGG as opposed to his live performance on Orfeo. The list goes on, with one example of superior musical or recording integrity after another – with differences that varied between the interesting but academic and the shocking but exciting.
Mozart’s Sinfonia Concertante K.364 is perhaps the perfect choice for this exercise. Not only does it play heavily on the tonal contrast between violin and viola, but enduringly popular it has been recorded across the years by multiple artists in an almost dizzying range of styles. Of the early stereo recordings, Decca’s 1963 impression, featuring the brother’s Oistrakh is deservedly highly regarded – leading to the almost inevitable slew of supposedly superior re-issues. I don’t have the original LP, but amongst my collection you’ll find a Universal/Decca gold CD and an FIM XRCD. Listening to these two on the 10 Series amps, it’s hard to credit that it’s the same recording. The gold CD sounds thin, pinched and gutless in comparison to the warmth, dimensionality, full-bodied swagger and instrumental interplay of the FIM disc. The instrumental conversation at the heart of the performance, the character of the key instruments and the way their exchanges lead you through the piece is far more convincing. This is a musical as opposed to a sonic distinction.
Now add the Pentatone SACD to the mix and things get really interesting. The 2007 recording features Julia Fischer in her pomp and highlights the dramatic change in musical style and recording technology that occurred over the intervening four decades. The playing is more precise, angular and incisive, matched by the recording’s clarity and increased focus on the individual instruments. The agility and poise of Fischer’s bowing will be strikingly familiar to anybody who heard her playing at this time, that intense combination of power and technique. But at the same time, while she rises to the challenge of the exposed, spot-lit presentation created by the recording, one wonders whether the lyrical sweep, graceful symmetry and innate communicative qualities of the Oistrakh’s performance doesn’t strike a better balance. Fischer’s brilliance does overshadow her partnering soloist and raises the question as to which set of artistic decisions you prefer. Whilst there’s no escaping the slightly incongruous nature of the heavily upholstered Moscow orchestration, smaller, more agile ensembles present their own challenges. It’s a fascinating musical and artistic conundrum and, if the contrast between recordings like the 1958 Philips Felix Ayo/I Musici recording of The Four Seasons and Amandine Beyer’s performance with the seven members of Gli Incogniti is way less equivocal, this level of insight is exactly what makes music so fascinating – and exactly the level of insight high-end audio should be providing.
In use, these amps provide a string of similar experiences, examples of the effortless access they deliver. From the dramatic contrast between the instrument Sol Gabetta plays for the Elgar Cello Concerto and her usual instrument, used for the Martinu Concerto on the same Sony disc to the contrasting styles of great pianists: the delicacy and poised phrasing of Mitsuko Uchida, the explosive dynamism and positivity of Jan Lisiecki or the lucid articulation of Clifford Curzon. The character and significance of each is effortlessly revealed by the 10 Series amps, just as the voices, characters and different venues are laid bare on Heartworn Highways or Jim Wight’s sardonic and pointedly twisted vocals penetrate deep beneath the surface veneer of US social norms. But in the long term it’s the expressive and communicative subtleties that are even more important. That might be the astonishing depth that Uchida brings to Beethoven’s Fourth Piano Concerto or the stark difference in musical subtlety and insight between the first and later CD release of Benedetti Michelangeli’s Beethoven Concertos and the SHM SACD version. This is as far from the musically muscle bound delivery of most ‘super-amps’ as you can get. It’s all about the finest musical nuance, the weight of a note and the space between it and the next, the natural sense of pace and time, the lowest and least intrusive noise floor – all backed up by the kind of stick that only 300 seriously quick Watts can provide. What the 10 Series rams home in no uncertain terms is just how much of a performer’s expressive range and technique is smeared, air-brushed or simply obscured by other amps. It’s not just the utter clarity that’s impressive, it’s the unforced ease with which it is achieved, the fact that you just don’t notice them working.
They say it is difficult to prove a negative, to demonstrate when something doesn’t happen. Well, it’s not hard to hear it! When it comes to system sound, the 10 Series are simply not part of the equation. Stirling Trayle talks about “quieting” a system – where noise is considered anything that doesn’t happen in the right way, in the right place and at the right time. Wadax talks about “eliminating error”. Both are useful concepts in understanding not just what the 10 series achieves, but how it does it and, along the way, why it defeats the law of diminishing returns. I already said that what’s important about these amps is what they don’t do, but let me explain that further. Let’s just suppose that a system properly reproduces 99% of the recorded information. You might think that doesn’t leave much room for improvement, but look at it through the other end of the telescope. If you can improve that percentage by half a point, you’ve reduced the system error by 50% – and that matters! Just as your eyes fasten not on the snow blanketed vista but the line of footprints that stretch across it, because your ears are your primary defence mechanism, your auditory system pays more – much more – attention to what shouldn’t be there than what should. Listening to the 10 Series that construct makes perfect sense, as well as explaining why apparently small quantitative differences can have such a profound impact on musical performance. The earth doesn’t actually have to move in order for the earth to move – and post 10 Series my earth has most definitely moved.
The CH Precision 10 Series has fundamentally changed my expectation of just how little an amplifier – any amplifier – can do. Transcending the traditional categories of tube or solid-state, high or low power, it has redefined musical performance, irrespective of partnering equipment or system context and it’s done it by doing less: doing less damage, imposing less compression, adding less noise and confusion. In doing so it gives each recording and each performer their own distinctive voice. In doing so it brings those voices to life. It’s contribution is so essential to convincing musical performance that although a single 10 Series component will significantly improve a system, you’ll find that two of them together are going to deliver more like four times the benefit!
This stuff doesn’t happen very often (the last product to perform the exponential improvement trick was the Lyra Connoisseur phono and line stage – almost 20 years ago) so I’ll say it again: sometimes things really are just better – and this is one of those times. Very few of us will ever be fortunate enough to own CH Precision’s 10 Series components but before you dismiss this as another hagiography dedicated to absurdly expensive kit, pause to appreciate the benefits. The 10 Series has already generated trickle down benefits to the 1 Series, with more undoubtedly to come. But the real benefit lies in the gauntlet they throw down to the competition, the impetus they’ll add to the market in general. First exposure to a product like this can be as disturbing as it is exciting, but as a wise woman once sang, “It’s a new dawn, it’s a new day, it’s a new life for me, and I’m feelin’ good!”
Type: Dual chassis, line-stage preamplifier
Inputs: 8x Line-level (4pr XLR, 2 pr RCA, 2pr BNC)
Outputs: 2pr XLR, 1pr RCA, 1pr BNC
Dimensions (W×H×D): 440 × 133 × 440mm each
Weight: kg (PSU) kg (Amplifier)
Type: Dual chassis, user configurable, solid-state amplifier
Inputs: 1pr XLR, 1pr RCA, 1pr BNC
Outputs: 2 prs 5-way binding posts/channel
1 pr XLR (pass-through)
Rated Output: 2× 300W/Ch (8 Ohms),
2× 550W/Ch (4 Ohms)
1100W/Ch (8 Ohms bridged)
Dimensions (W×H×D): 440 × 285 × 510mm each
Weight: 78kg (PSU) 53kg (Amplifier)
Finishes: Grey, Anthracite, Champagne Gold
Prices: L10 stereo – £65,000
L10 four-box dual-mono – £111,400
M10 stereo – £83,600
M10 pair, mono, single-input card – £157,800
Manufacturer: CH Precision
Sàrl, Préverenges, Switzerland
10 Series: ch-precision.com/ch-cat/series/10-series/
CH Precision distributors and dealers near you: ch-precision.com/where-to-experience/
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