I've been watching this thread with interest as I have been playing with the idea of another Class D amplifier build, but I have what might be considered a very basic query - but this is not really about the build, its more a about whether such a build is actually worth pursuing just now?
You see when my Line Magnetic tube amplifier went pop it had to go away for repair and I was left without any kind of amp in my main system. Just as a bit of fun (and after reading a few reviews) I ordered a Fosi V3 TPA3255 based little desktop amp with its counterpart P3 tube pre amp, I thought I would have a bit of fun whilst my main amp was away and then I would have a spare for maybe the bedroom when the big amp returned.
Anyway, to cut a long story short I was amazed at the amount of power (with 48v power brick) on tap, my speakers had never been so well controlled, plus the information retrieval was nothing short of eye opening for me, what a silly little amp to make such a grown up sound! I've been in this hobby for decades, many bits of kit have come and gone, some ridiculously expensive and some quite sensible, but I've never countenanced shoving a £99 amp on the end of a Lumin U1 Mini feeding a Denafrips Pontus II front end!
So of course as a complete hifi nut I soon thought much better could be achieved by a 'proper' Class D design, so keeping funds at a reasonable level (because one day the LM will no doubt arrive back!) I built an ICEPower 125asx2 kit, which dwarfed the Fosi and was duly placed in charge of music making at chez Tim!
After a couple of weeks I started to notice I was skipping tracks, unticking previous favourite albums and it came to me, maybe this ICEPower wasn't the bees knees I presumed it would be. So as an experiment I put back the Fosi combo and well, all my prejudices went out the window. Of course the Fosi could not quite match the power and speed of the ICEPower design, but compared to a wall of sometimes ear splitting data, the Fosi just seemed to separate the strands of the music much better. There was no loss of information at all, the tiniest snare tap, the slightest intake of breath were all apparent - they just sounded so much, well, nicer? More real? I even listened to a David Sylvian 'best of' all the way through, and it sounded great, even the distorted 80's synths!
So, my hifi rack is is looking a bit unbalanced, with big esoteric audiophile boxes on the bottom rungs and a set of toy town amps on the top

and I would love nothing more than to plonk another big black class D amplifier build up there...but seriously, if a factory built mass produced crowd pleasing bit of kit like the Fosi can sound so amazing, is there really a worthwhile improvement in sound quality from something like this latest 3255 design at three times the price?
Not trying to be a troll or anything, I am genuinely fascinated by class D now and for what we seem to be able to get for the money. I'm thinking the Line Magnetic, when it arrives back, could soon be looking for a new home - releasing funds for a very interesting build from one of Bruno's latest designs?!