Marty, you need speakers that are bi-amp-able, then use one M10 with feedback for the bass and one M10 without feedback for the restHere’s a two week update on the CH M10s. The issue is which M10 to report on. In its purest form, without the addition of any global feedback, the M10 is in many ways, and this is key-only on some material, perhaps the finest amplifier I have heard. The definition, musicality, sound staging, and tonal rightness are all superb and easily among the best available. The amplifier has a natural sound quality that is neither yin or yang but is rather, beautifully balanced. This is most welcome particularly on classical music where the timbre of individual instruments is often simply ravishing. The same is true for female vocals. But there’s a catch. All is not without some serious remorse. The amp’s Achilles heel is low frequency material, particularly below 80 Hz. Here, without the addition of some modest global feedback, bass performance is surprisingly below average at best. For the life of me I do not understand how anyone can think this a good bass amplifier (forget about great). It is not. To compare its performance in the bass range (again, an important qualifier) to the Parasound JC1+ is frankly an embarrassment. The JC1+ is so vastly superior (it is the best bass amplifier I have ever heard, and that includes the esteemed Soulution 701) that this sort of comparison is a sonic equivalent of “the king has no clothes” when describing the M10. The bass, again, without global feedback, leaves me thinking “can’t everyone plainly see (or in this case, hear) the king is naked”? Even on classical music, the lower bass register, whether it is the piano left hand, male basso or baritone, or the almighty lower brass are just, well, wrong. There is no sense of high definition and impact to the low frequencies on a “zero global feedback” M10. The bass frequencies are softer than they are in real life and are therefore unimpressive. It’s not an issue of balance or weight or extension, but rather an issue of definition and hence dynamic impact, as I hear it. But the rest of the range? Very impressive and even wonderous. (While no two amps sound the same, my limited audio memory brings to mind that the M10 resembles the sort of sound Jeff Rowland’s amps are known for; eminently musical and rewarding, but even more so).
So knowing that this liability in the bass is something that is a concern, is there a path forward for me with the M10. Well, yes, but it’s sort of cheating in a way and brings me to discuss the “other” M10- the one with global feedback applied. Recall that I am running the Alexx V full range and supplementing with the JL Gotham subs using a second pair of preamp outputs. I’m now able to crossover the subs at about 28Hz (rather than 25Hz) and although this doesn’t seem like much, it now allows for a blended system sound whereby the liabilities of the CH 10 in the 20-40 Hz range are now effectively masked by the sub’s contribution. It’s sort of a parlor trick if you will, but a discerning listener tell there is something to be desired in the remaining bass range up through 40-80Hz as the sub contribution is nominal in that range. What to do? The answer is obvious. Turn up the global feedback and try to improve the overall bass performance so that it is not only tolerable, but use a low enough amount of global feedback so that it does not impair the magic of the M10 in the rest of the audio range. Have I been successful? In a word, yes, more or less. I’m certainly glad that CH allows for adjustment of global feedback in 1% increments. Without it, this exercise would be impossible, as small differences translate quickly into easily heard satisfactory and unsatisfactory value settings. For me, I have settled on 14%. In doing so, I can live with the bass combo provided by the Alexx V and the JL Gothams. But more importantly, the rest of the range, which not quite at the level of “incredible” that the M10 provides without global feedback, is still pretty damn fine. Here, it should be said, the JC1+ is not its equal, even with some modest global feedback applied to the M10.
Taken together, the Alexx V, the JL subs set to ~28Hz, and a global feedback setting of 14% provided some of the most exquisite listening I have yet to hear from my system. I was listening to one of my “go-to” piano recordings, the incredible dual piano Salzberg album by Martha Argerich and Nelson Freire and was simply mesmerized by the pianos, not only sounding more authentic than I have ever heard them before, but with spatial localization of the two pianos and their individual registers that was not previously realized.
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This highlights but one aspect of what the M10 is capable of doing. Although it was sonically not quite the equal (particularly for the upper registers) as to using zero global feedback, my settings nonetheless afforded a genuinely satisfying result for the overall blended Alexx V/Gotham system. This may be a comment out of left field but through the M10, the tonal density of the piano as well as many other instruments including voice is very reminiscent to that which I hear as a hallmark of the Zanden 1200Mk3 phono stage (which for me, is high praise indeed).
Equally important, is that the sound of the system when playing big music, especially rock, world or music with deep bass rich transients, is also now very satisfactory, although there will always be a part of me that understands that a small bass range between what the Gothams’ cover and what the M10’s provide on the Alexx V, will always be bettered by the JC1+. It is why an adage such as “perfect is the enemy of good” is as relevant now as ever. I will always wish that the M10 had bass that was able to shine when the global feedback was set at 8%, which is where I think it becomes darned close to sounding like no global feedback at all. But that just isn’t going to happen so for now 14% is where it needs to be for best overall sound, which honestly, ain’t too shabby.
What you just read is a more lengthy explanation for describing what Mad Floyd (Ian) said far more concisely in an earlier post. The M10 is really 2 amplifiers. Turn off global feedback and its tube like qualities will surely impress. Add global feedback, and the potential to sound more like a SS amp, occurs with better bass at the slight expense of the rest of the range. The trick is to reach a balance in one’s system that enables their use in the manner best suited for a particular listener and their system. Will my current configuration and their results ultimately translate into satisfactory long term listening? I certainly hope so. But for the first time since I’ve received them two weeks ago and largely broken in, I think so.
I guess I’ll find out. Stay tuned….!
Problem solved