I agree with Atmasphere. Many designs are nothing to write home about, made to a price point very similar to each other. Other designs use better parts caps, resistors, custom transformers, etc. Measurements mean nothing to me as I cannot hear the differences (general statement). I recently made a Pass labs clone using better parts and it sounded really, really good, we were surprised how good it came out. Some designers are exceptional and go the extra mile. Making something cheap and real good is a challenge if you use custom parts though IMO. I have yet to hear a SS amp sound like tubes depending on the design IMO. I heard a FM Acoustic power amp and that was the closest SS amp that I really liked. Very expensive. No special parts so we figured that they matched up the parts very closely, but I don't really know. In designing products, I can basically tell you how something will sound by the design, the parts used, etc. I listen so much for changes, etc., that I really never hear the music for enjoyment now a days. So far in my limited listening to class D designs, I can hear the sound and while I can enjoy it, it is really not what I prefer to listen to. Not saying that I have heard enough but knowing that design I can hear what I do not like in that design. But what I prefer may be different than what you prefer and its all good! That is all I got! Happy Listening.
