Hi WC, thank you for your notes on the Rowland M535 in stereo mode. I am not surprised that a single M535 chassis with its 250W per side might not be a best match for your demanding Martin Logan Neoliths… Similarly, a single M535 falls a little short of ideal for my Vienna Die Muzik… A sheer matter of power, regardless of the extensive break-in that I afforded the amp. As I may have mentioned, and also you observed, a single M535 does a good job at yielding a stage that spans the virtual space between the speakers (about 9.5 feet apart in my case), however the stage does not exceed the outer boundaries of our demanding speaker pairs, and image sizes seemed to me a little shy of ideal. Furthermore, while the stereo unit never struggles, its authority seems to approach its upper limit on Die Muzik… Different story with a bridged pair, where in my case the stage appears to exceed the 19.5 with of my listening space, and the virtual image of a grand piano has a size congruent with a living instrument. On the other end, the patient break-in of your single unit would at least reveal the kind of organic glow that the amp is able to generate… No, not three years…. But extending break-in for a few weeks would show you what the stereo amp amp is capable of exposing of the intimate structure of the music… Dry is hardly an attribute that I would ever associate with this device.
Yet, the stereo unit will always fall far short of the sheer magic of a bridged pair. As KLH has pointed out, my own assessment of M535 as a reference piece is not of a single stereo unit, but concerns a bridged pair enhanced by the slip-on caps, where 900W per side and a 30A power supply in each chassis make all limitations outline above disappear, and the performance does graze M925 territory. By contrast, a single M535 does not approach the performance of M925 monos, as much as some participant of this thread ardently hopes for. Thus I hope that you will be eventually able to reinsert M535 into your system, and obtain a second unit for bridged operations, and bring the pair to full bloom.
I confess that I have had in my system but a risible fraction of the number of amps that you have experimented with. On the other hand, my tonal reference might be slightly different from yours, in that it is not based on a particular class of operation, nor a particular brand or amplifier model. Rather, my reference is the sound of live unamplified instruments, the perception of the intentionality of the performers, their deliberate interpretation as well as their unintended flaws, not to ignore those residual extra-musical cues which hopefully a top system may allow to emerge. Besides the living performances I have attended on both sides of the Pond, my live models are those instruments which I have dabbled with at one time or another, or I am still fiddling with, such as piano, harpsichord, pipe organ, baroque recorders (piccolo, soprano, alto, and tenor), flute, Bb trumpet, short Bb cornet, Eb cornet, flugelhorn, and euphonium… Cello instead I do not play, just coached for some 12 years. So, my perspective, right or wrong that it might be, may be a little different from yours.
IMO, seeking a literal reproduction of live acoustic music may be a fruitless endeavor… What might be realistic instead is to achieve a form of augmented reality whose perspective is somehow congruent with the live experience, and yet different from it… No, I won’t expand further on this subject in this thread… This is WC’s sandbox after all.
I should point out though, that rather than “getting used” to certain amps, I have found that a very small number of amps, such as the Rowland M925 monos and the bridged M535, yield what I am looking for.
This does not imply that there are no other amps or brands which fit my model. Over the years, I have auditioned a handful of brands of amps at home or at RMAF which, using a variety of technologies, also yield exactly or almost exactly what I aim to... I never had to "get used" to them... It has always been love at first sight... Or, I should say, "first sound!"
The one which as delighted me most at RMAF, and which in fact has taken my breath away, is Soulution… They generate a musical environment that matches my tone concept 100%. I should add DartZeel and Luxman as reference-level SS brands which I have found almost as enchanting. Other SS amps, well… not so much.
Moving to tubes, every time I listened to ARC reference series tube amplifiers I also felt that they were matching closely my musical ideas, if perhaps a smidgeon less than Soulution… And equally delightful were the VTL Siegfried and 450 monos.
In the current class D domain, the Merrill Element 118 are IMO amps to watch closely… I had the honor of having a yet incomplete prototype pair in my own system – sadly only for a few days last year… Except for some slight excesses in the treble which were likely an artifact of incomplete break-in, they did create an incredible immersive experience, which was, like the examples cited above, an immersive hyperreality consistent with unamplified live music. Do not think for a moment that if you are familiar with the lovely Veritas you already have a significant idea of Element 118… The latter is a very different and much superior beast.
Regards, Guido
PS. Apologies for the long post.