Having experienced life with the QuintEssence Amplifiers, and having been the owner of potentially nearly every variety of amplifiers, including Solid State Class A, Class B, Class D, as well as Push Pull Tubes, SET, and lastly my OTL Amplifiers (of which I've explored various models), I can say that my understanding and appreciation of these devices have greatly expanded.
Undoubtedly, these have been the finest amplifiers I've ever owned. Interestingly, it's the only amplifier whose sound I can't categorize as either Solid State or Tube Amplifier - it possesses an uncanny blend of both, yet doesn't distinctly sound like either. Harmonically its spot on, it's robust yet nimble, dynamic with finesse and control.
I haven't yet tested the amplifier with heavy-load speakers that dip into the 2-ohm ranges, but so far, it has performed with various speakers (all reasonably easy to drive).
In my opinion, if you're seeking a musically rich and emotionally magical experience devoid of any typical amplifier shortcomings, these represent the zenith of amplifier design.
Being a Class A amplifier with 60 watts at 8 ohms or 100 watts at 4 ohms, it's compatible with most speakers.
My experimentation revealed that it controlled four 12-inch bass drivers more effectively than the Class D Hypex Amplifiers.
It appears to exhibit the same level of transparency as my OTL Amplifiers, but with an added touch of finesse and a richer resonance in the midrange. Moreover, it exerts greater authority and control over the lower frequencies. I've observed that it doesn't compromise on transparency, yet it manages to blend the entire musical picture into a cohesive whole. The details are clearly presented, but they're never forced upon you