CH Precision L10 Preamplifier and M10 Power Amplifier

by Marc Mickelson | February 6, 2023

© www.theaudiobeat.com

CH Precision is a brand that almost seems to have been conjured from thin air. One day it was relatively unknown, and the next it was everywhere -- on magazine covers, in reviewers' systems, in dealer demo rooms and show systems. Such omnipresence may seem unusual until you know a bit about the company and especially the people behind it. Florian Cossy and Thierry Heeb -- the C and H in the company's name -- began their audio careers at Goldmund, the Swiss full-line audio manufacturer -- source components to speakers -- that was dominant in the 1980s and 1990s. Goldmund's reputation in the US was built almost completely on reviews in The Absolute Sound, the company's Reference and Studio turntables becoming high points in what was then the upper crust of analog playback.

Florian Cossy went on to found Anagram Technologies, a B2B company whose digital technology was used in various high-end products, and Orpheus Labs, a manufacturer of digital processors and players that used Anagram technology. I first met him at a CES around 2000, and he immediately struck me as a young guy who would have a long career in high-end audio if he wanted it. In those days, young guys with technology backgrounds could easily find lucrative work in the computer and consumer-electronics industries, but Cossy was committed to audio engineering, and here he is, twenty-plus years after that CES heading a company that's a red-hot audiophile commodity.

I first heard a CH Precision product in my own system by happenstance. A few years ago, one of the company's P1 phono stages ($31,000), with an X1 power supply ($17,000), was making the dealer and show rounds here in the US. Knowing that it needed new shipping boxes (the existing ones were battered and had grown an outer shell of packing tape), Roy Gregory suggested to the people at CH Precision that having it spend time at my house while new boxes were dispatched was a good idea. I was completely floored by the P1's sound -- or, should I say, by its lack of a sound. Forget transparency -- the P1 gave the impression of being an extension of the phono cartridge itself. I was very sorry to pack it and the X1 in the new boxes when they arrived. I was sure I had only scratched the surface during my week plus of listening.

Because of that all-too-short exposure, I was extremely enthusiastic to hear and write about CH Precision's L10 and M10, this time in more leisurely circumstances -- more on this below. These are CH Precision's most exacting and expensive preamp and amp, and they mark the company's tenth anniversary.

The L10 and M10 are two-box affairs, the L10 arriving as two separate units that can become four, with the addition of a mono line stage and its accompanying power supply. The L10 is large and heavy -- two chassis each measuring 17 3/8" x 17 3/8" x 4 3/4" and weighing 44 and 51 pounds -- but the M10 is massive and massively heavy: two 17 3/8" x 19 5/8" x 10 3/4" chassis that weigh 117 and 172 pounds. For both products, certain circuit boards can be added, subtracted or moved, depending on system requirements, lowering overall cost in some instances. The preamp and amps arrived strapped to pallets in well-designed, heavy cardboard boxes, accompanied a few days later by Kevin Wolff, CH Precision's head of international sales. While I was safely able to unpack and place almost everything, I waited for Kevin's help in tackling the M10's power supply. Even with two sets of hands, the power supply is a grunting weight. It's just big enough that one-person movement is a possible threat to the mover and the item itself.

Roy Gregory has written about CH Precision's manufacturing methods -- the products' "card-cage construction," which is more computer than audio industry -- but what sets the company apart from nearly all of the audio crowd is its reliance on another aspect of computers: software. CH Precision products, especially the preamps and power amps, allow adjustment of operational parameters that is, as far as I know, not equaled by any other products made today, and it's all accomplished via software, essentially each product's operating system. This gives each the ability to fit into any system, no matter the owner's requirements -- "100% of what exists on this planet," as Florian Cossy put it to me. I'm not just talking about ergonomics but performance, with any source or speakers. This is the technological high ground that the Mark Levinson brand, under Madrigal's direction, once staked out, although not to the same degree as CH Precision does now.

Kevin Wolff referred to the M10's channels as "rails," a concession to the fact that the M10 can be configured in multiple ways. It is most readily a traditional stereo amp with both RCA and XLR inputs, in which case it outputs 300Wpc. It can also be a mono amp that outputs 600W or, if both channels are bridged, 1100W. It can additionally be used in what CH Precision calls, active or passive biamp mode. The difference is that in active, only one input is required and in passive two are required. That's five different fundamental ways to use the M10, all selectable from the unit's operating menu.  A peek at the M10's back panel was reminiscent of an airplane cockpit, but all of the connectors made sense once I knew a bit about the amp. As a nod to user friendliness, the connections are color-coded, making hook up much easier.

Of course, some other amps can function in multiple ways, but the M10 goes a couple of steps further toward universality with gain and feedback adjustments. Gain is adjustable in 0.5dB increments, from 18-24dB in stereo, mono and biamp modes, and 24-30dB in bridged mode. Global feedback is adjustable in 1% increments from 0-100%. Both of these allow tailoring the amp to the speaker system in use. You can adjust the gain to dial in the balance between a speaker and passive subwoofers, and do the same with feedback, all from the listening seat.

When you see photos of the insides, you see work that is easy to attribute to Swiss precision -- and this segment of high-end-audio extremism. The M10 has enormous filter capacitors in each chassis, each the size of a liter can of water or juice, and they are split between the chassis, so certain ones can be close to the output transistors. CH Precision places great emphasis on each product's power supply. "It is the key," Florian Cossy told me. The L10 and M10 were two years in research, design and development. Cossy: "We design based on the numbers, then measure, measure, measure, and then listen." Each M10 has over 3000 components and requires a day and a half to build.

All of this tech talk doesn't touch on the sheer elegance of the L10 and M10, both physically and in use. Nothing about them was left unconsidered. The user interface is easy to navigate, whether by tablet or from the product itself. The screen on each product is large enough for easy viewing but not so large as to take over the front panel. One of the most intelligent touches is also the one that essentially no audio company considers. The spiked titanium feet are attached to long Delrin rods that screw into place from the top of each product instead of requiring placement underneath and the fumbling that ensues. Given this arrangement, there is an advantage to stacking the products, as the spike-tipped rods create a single path for energy dissipation from top to bottom, terminating in whatever is underneath the bottom chassis. CH Precision supplies Delrin discs that fit into the wells that expose the top of the rods, protecting the chassis. There's simply nothing like this configuration in all of high-end audio.

Last but not least. CH Precision provides terrific documentation that explains all of the ins and outs of the L10 and M10, both in written and pictorial form. So an owner can get up and running quickly and then experiment with the products and their many features as time allows. Having written technical manuals, I commend CH Precision on making sure its documentation is concise, descriptive and complete, not a glaring weak point for products that are made with extreme care and attention to detail.

I used the L10 and M10s -- two of the amps -- with an especially wide array of electronics and speakers, a months-long exercise that helped me understand the capabilities of these endlessly capable electronics. They arrived while I still had the Wilson XVX speakers and Subsonic subwoofers -- altogether about a ton and a half of highest-fi audio gear. After the Wilson speakers and subs departed, I used the CH Precision electronics with a disparate group of other speakers, including Stenheim Ultime 2s, JMlab Utopias, MartinLogan Odysseys, and Klipsch La Scalas. Each of these revealed much about the electronics, even while their intrinsic sound was utterly different. The Wilson system's extreme bandwidth, tonal density and bass depth were all on full display with the L10 and M10s; then, in contrast, were the immediacy, bass detail and airy soundstaging of the Stenheim Ultime 2s. No one would purchase the CH Precision electronics to use with either the MartinLogan Odysseys -- $6500 per pair, circa 2001 -- or Klipsch La Scalas -- my pair manufactured in 1985 -- but both revealed facets of the preamp's and amps' performance. The MartinLogan's received a shot of adrenaline from the CH Precision electronics, especially with the pair of amps for biamping. They sounded faster and far punchier than they have with other electronics I had on hand. The Klipsch La Scalas, which are a project I may write about, are 105dB sensitive and therefore extremely revealing -- even unforgiving -- of any noise from the equipment in front of them. I knew from listening that the CH Precision L10 and M10 were quiet, but only when driving the La Scalas did I know how quiet: as silent as a tomb in deep space, even fronting speakers that can play blisteringly loud with a single watt of power. Not even the faintest hint of hum, hiss or buzz came from the tweeter or any of the drivers, a feat not matched in all my time as an audiophile.

I also shuffled other preamps and amps into the system to use with the L10 and M10s, so I could discern the sonic signature of each. While it was certainly possible to change the sound of the system with other electronics, more than with any other preamp-amp pairing I've heard, I would not use the L10 and M10 with other products and thus alter all that the duo does so well -- all that CH Precision designed the products to achieve. This is certainly a conclusion born of maintaining a consistency of sound from source to speakers; however, even more so, it is a matter of good practice where this preamp and amp are concerned. I've never heard audio electronics sound quite like these -- not even the reference equipment I own and know very, very well. For that reason, it just makes no sense to "remaster" what's significant and unique about the CH Precision preamp and amps by mixing it with some other palette of shades just to create a different, and not better, sonic picture. This may explain why we so often see stacks of CH Precision equipment: in design and execution, from their almost interlocking spikes to their utter noiselessness, all of the company's products are meant to be used together. Because of analog's special needs (all that gain required), there is one CH Precision product that I can envision adding to a system of other companies' components, the P1 phono stage. But be forewarned: the P1 could lead to the situation with certain chocolate candies: one is not enough.

This is a good place to begin the discussion of the L10 and M10's sound, as much as I can discuss their sound, which is defined as much by what's missing as by what's present. The bedrock is that lack of noise of any kind. This is not some kind of audiophile party trick; it has significant musical consequences. The L10 and M10 have the purest and most direct presentation I've heard from audio electronics, like water turned into sound. This isn't a byproduct of some canny combination of pleasing colorations, but instead a complete lack of them. Once the noise is absent, the signal is all that's left, and that quality is easy to hear and admire, especially if you've been around the audiophile block with other electronics. The Tone Poet series of jazz reissues has one inherent flaw: there are so many of them, and they are released so rapidly, that it's difficult to keep up with all that's available. The recent mono version of Blue Train [Blue Note/Tone Poet B0035203-01] was released along with the expanded two-LP stereo version [Blue Note/Tone Poet B0035204-01]. Both are wonderful listening, even if you have multiple other digital and analog copies, as I do. The quietness of the vinyl enhances the overall resolution of both recordings, but there is a special magic with the mono, a purity and directness that the L10 and M10 revel in. When Coltrane enters on "Blue Train," locked in air between the speakers, time melts away.

We audiophiles are conditioned to be skeptical of unusual differences from product to product. They're more about listener preference than true sonic improvement, so the explanation goes. Not here, even though what I describe is not as overt and showy as, for instance, subterranean bass or midrange fullness. However, it is more musically significant, because it affects all music from top to bottom, making it at once sound more vivid and precise and at the same time more natural, even relaxed. Resolution is as high as it gets, but that's resolution of the music alone, not the music with self-noise from the electronics. The various Lamm products that I've reviewed come most readily to mind when I use the word natural, but it applies even more so to the CH Precision L10 and M10, because of their unique presentation of music devoid of amusical noise.

The spectral balance -- the perceived evenness of tone from top to bottom -- of these electronics is as ideal as I've heard, neutrality and transparency as absolutes. Again, I've cited Lamm products as exemplars here, but there is no doubt that they sound somewhat darker than the CH Precision L10 and M10. But the CH Precision take on neutrality is not the lean, gray, antiseptic kind of other so-called neutral electronics. The L10 and M10 are supremely balanced, never tipping one way or the other in pursuit of their neutrality. I've written in the past about the information gleaned from listening to different versions of the same recording. The equipment will or will not reveal the differences in the mastering and source materials, and they will make the recordings sound more alike or more different. The L10 and M10 were the very best at this that I've encountered, while never turning the music into an over-analyzed mess. And with the best versions of a particular recording, like the MasterSound SBM gold CD of Kind of Blue [Columbia Legacy CK 52861], it was easy to become involved in the music and forget about analysis. Again, the L10 and M10 come by this deep insight honestly, through purist means, and it has purely musical ends.

The bandwidth and dynamics of the CH Precision pairing are thrilling with all kinds of music. I actually pulled out a couple of British Decca LPs -- Romantic Russia [Decca SXL 6263] and Nights in the Gardens of Spain [Decca SXL 2091] --  that I have owned for a while but never played, just to hear them with the CH Precision electronics and Wilson speakers and subs, before all of the hardware was gone. I have owned these for a while, part of a record collection I bought from a guy who cleans out houses, and I immediately understood why these LPs are so prized. The natural rendering of the instruments and the space in which they were recorded was stunning in its acute ratio of presence to air. The only recordings I've heard that do the same thing are those that Mark Levinson, the man himself, made in the 1970s, like The Six Schubler Chorales [Mark Levinson MAL-1]. But its portrayal of the instrument -- the H. Frank Bozyan Memorial Organ in Dwight Memorial Chapel on the campus of Yale University -- is gentler and the space of the venue more pronounced. Harry Pearson labeled the Levinson LPs as having "Musically natural sound, as opposed to spectacular per se," and he was correct, that lack of hi-fi showiness being showy in a different way.

For a change, the bass-drum whacks on Telarc's "Fanfare for the Common Man" from the SACD of Copland and Hindemith compositions [Telarc SACD-60648] were huge percussive whomps -- sharp and powerful, a punch to the sternum -- but the tam-tam crashes were even more impressive: quick, steely bangs followed by seconds-long decay. But in keeping with everything else the L10 and M10 achieve, all of the fireworks were integrated into the presentation. With the Wilson XVXes and Subsonics or the Stenheim Ultime 2s, the CH Precision electronics produced true reference sound and would just as readily impress tube lovers as listeners who lean toward solid state.

An exercise I've gone through for other products I've reviewed is choosing a recording whose sonic characteristics are similar to those of the product itself, as a way of summing up the product's sound. A recording that summed up the L10 and M10 for me is an oldie but goodie, R.L. Burnside's First Recordings [Mobile Fidelity UDSACD 2026]. Putting aside that it's a set of demo recordings in mono, its combination of immediacy -- "spooky" is what I've called it several times in the past -- and presence put it in a rare category of the most real-sounding recordings I've ever heard. It would draw attention played on a boom box, but the CH Precision electronics seemed made for it, their purity and expert balance matching the recording step for step. I've mentioned First Recordings in other equipment reviews, but the impression it made with the CH Precision L10 and M10s was something very special -- reproduction that is unlike any I've heard, anywhere and at any time. I will continue to listen to it for the music, but I won't forget the otherworldly sound with the L10 and M10s.

I had an unusually long listening period with the CH Precision L10 and M10s, with an unusually large group of components, and in every case, with every recording, I always thought that I was not just hearing the music, but hearing right into the recording. Such is the sense of having a line back to the microphone that these products create. They produce fidelity at its very highest level, their design addressing the fundamentals of audio engineering to the utmost in order to maximize the purity of the musical signal. The L10 has enough inputs and outputs to be usable with the M10 and its various operating modes, which makes the two of them compatible with any ancillaries and speakers. And even with their added complexity, both products are user-friendly in the extreme. You can set them and forget them, or tweak to your heart's content, and the user interface makes both approaches feasible.

My one-time colleague Paul Bolin sometimes used an oddly artful phrase, "Something other than else." It sounds like Yoda, but Paul attributed it to Monty Python. It popped into my head as I thought about my experience with the CH Precision L10 and M10. These are extreme electronics from which one might expect a more extreme version of what other electronics achieve: bigger dynamics, deeper bass, greater drive, solid-state sound at its absolute apex. I could argue that all of this is true, but what sets the L10 and M10 apart from the rest of the market -- and I do mean every preamp and amp I've heard -- is the way they defy the usual, creating a new paradigm for reproduced music in the process. There is a purity to their sound that really must be heard to be comprehended, a directness that gets to the heart of every recording without coloration or flavor. Their sound is unadulterated, an accurate and musically consonant version of whatever flows through them. An analogy I can give from previous experience is what certain SET amps driving certain high-sensitivity speakers achieve with the right recordings, but here it was with high-tech, high-power solid-state electronics, a variety of speakers, and anything I cared to play.

I'm going to suggest something I never have in all my years of writing about audiophile equipment: other designers should hear the L10 and M10, not so much because they will change minds (designers of audio equipment are an intractable bunch), but because they so clearly and forcefully illustrate what is possible in both the design of audio electronics and their sound (or lack of it).

Prices: L10, $76,000 in silver finish; M10, $104,000 in silver finish.
Warranty: One year parts and labor.

CH Precision Sàrl
ZI Le Trési 6D
CH-1028 Preverenges
Switzerland
www.ch-precision.com

Associated Equipment

Analog: TW-Acustic Raven AC and Grand Prix Audio Parabolica turntables; Graham B-44 Phantom Series II Supreme, Kuzma 4Point and Tri-Planar U2-SE tonearms; Denon DL-S1, Denon DL-305 and Dynavector XV-1s Mono cartridges; Lamm Industries LP2.1 phono stage; Meridian 562 analog-to-digital converter with Meridian 515 MC phono stage; Wadia 17 analog-to-digital converter.

Digital: Ayre Acoustics DX-5 DSD "A/V Engine"; dCS Rossini 2.0 digital playback system; dCS Rossini Apex DAC; CEC TL1 CD transport; Conrad-Johnson Premier 9 and Timbre Technology TT-1 digital-to-analog converters; Genesis Digital Lens data buffer; Audio Alchemy DTI Pro 32 jitter attenuator; Wadia 17 analog-to-digital converter.

Preamplifiers: Convergent Audio Technology SL1 Legend Extreme, VTL TL-7.5 Series III Reference.

Amplifiers: Convergent Audio Technology JL5 Limited Edition stereo amp, Krell Showcase 7 multichannel amplifier, Lamm M1.2 Reference monoblocks, Mark Levinson No.434 monoblocks.

Loudspeakers: JMlab Utopia and Mezzo Utopia, Klipsch La Scala (modified), Stenheim Reference Ultime Two, Wilson Audio XVX with Subsonic subwoofers and ActivXO crossover.