Yup. If the SINAD is no better worse than -40 dB, and the loudest the amp can drive speakers is 75 dBA, then distortion products will be down in ambient noise. But there are many dirt cheap products that can do that. Of course, distortion in this amp at rated power was more like -20 dB--it crossed the 1% threshold at 900 milliwatts. So, distortion products will be at 65 dBA if the peaks are amplified to 85 dBA, and I think even I could hear that.As @Blumlein 88 mentioned for $2.00 you can put a 4 ohm resistor in series with the speakers and get 90% of the SET effect. Distortion is over rated in my experience as it is hard to hear with actual music playing below very high levels.
I recall a speech by J. Gordon Holt where he challenged the assembled attendees at a S'phile anniversary dinner to continually strive for life-like reproduction. He said that we can hear a bit of live music from four blocks away (or something like that) and immediately know that it is live music and not reproduction. Whatever the reason for that, an amp like this is not a response to that challenge, notwithstanding the vacuous claims by the makers.
Rick "amplification has one purpose: to make the music realistically loud with as little damage as possible" Denney