I've been an audio enthusiast for many decades now, and have listened to and evaluated all sorts of audio equipment, some of it pretty high end. This amplifier presents a bit of a paradox to me. It does some things very well, and almost amazingly well for the price, while other things kind of rule it out as a an amplifier that would satisfy an audiophile.
First, a quick comment: This didn't come with a power supply, and it won't work without one. You have to provide your own 19VDC power supply, and I knew that. Fortunately, I had a number of them on hand, but you may not. In order to achieve the claimed 100 Watts per channel output, you'd presumably need a power supply that put out over 200 Watts total. Mine put out about 65 Watts, so I undoubtedly did not achieve the rated output.
First the good stuff. This amplifier is (1) amazingly quiet, (2), tiny, (3) cheap, (4) powerful, and (5) ... please read on. I want to describe the sound quality. It is virtually distortion free, clean, extended, detailed, with flawless imaging and the ability to hear deep into the recording and pick out things you probably never heard before. It reproduces (with good speakers) a nearly 3-D holographic space between two stereo speakers, and allows you to feel like you've stepped into the recording soundstage. These are qualities that many amplifiers don't always achieve, and qualities virtually unheard of with an amplifier this inexpensive.
But I hear a fatal flaw.
This is difficult to describe, but, as best as i can tell, this amplifier completely compresses the leading transients and microdynamics in a recording. While it certainly plays LOUD, what I hear is a major, fundamental, almost puzzling "what the?" kind of overall sound that significantly reduces the "you are there" kind of presence in a good recording. A sudden hard hit on the drums, the leading bite of a guitar chord, the sizzle of a close-miked brass instrument ... all mostly gone, replaced by a sort of homogeneous, lifeless, flattened sound dynamic. If I had to guess -- and this is truly just a guess -- the lack of any sort of power buffer in this amplifier, and the "just in time" switching nature of its technology, causes it to constantly lag (in terms of power) behind the leading edge of all musical transients.
This flaw, at least to me, eliminates this amp from any sort of serious contention as a piece of genuine hifi audio equipment. But that's still high praise for the design of the Tripath IC used in this amplifier, which enables it to perform well enough to even be considered in this sort of comparison. For casual listening to MP3 or Bluetooth audio (which is often highly compressed anyway), perhaps on a computer desktop, or in a kitchen or garage, or for just playing around with, you can't beat this amp. I'm keeping mine for sure.