I've been building and designing amps for several decades, on and off. Initially I was enamoured of getting the lowest distortion numbers but given the current arms race towards -140dB distortion levels (check out ASR's reviews of recent headamps) its become very expensive to verify such a level of performance. I have no desire to invest in a TOTL AP analyser, my aim is rather to satisfaction from music, something very subjective. What I am curious about is - is there any commonality between what I find subjectively satisfying and what others do? This question might be answered by having a very affordable amp which others can build themselves or obtain without major financial hardship then I'll be able to collect feedback from disparate sets of ears.
How to begin an amp project such as this? There are a couple of options - buy an amp 'off-the-shelf' so to speak or create one from scratch. The former path is the one I've chosen here and the 'off-the-shelf' amp is called a 'chipamp'. These days the fashionable chipamps are pretty much all classD, classAB chipamp designs all date back ten or more years. In the past I've had some fun with classAB chipamps (LM3886, TDA7294, TDA8566 to name just a few) but I wanted to try the latest tech and at the time there was huge buzz around TPA3116. A board with one of these on costs low single digit dollars so there isn't much to lose in trying it out.
Thanks for your interest - how it sounds is rather tricky to describe. The aim is to have an amp which is analogous to a clear window, how to 'see' a clear window? The clearest amp is one that maximizes the differences between recordings - it needs to minimize any of its own characteristic being added.