Who tried Class D only to return to S/S or Tube



And what were the reason you did a backflip back to S/S or tube.
As there are a few pro Class D threads being hammered at the moment, I thought I'd put this up, to get some perspective.

Cheers George
128x128georgehifi
Ait, I understand that choke helps storing and releasing energy, but it won't affect charging of capacitors that has to happen in very short time.
I showed the current waveforms through the first PS Capacitor in each case. It's clear that in one case there are sharp spikes through the cap, in the other there are not. 
The rectifier is not directly charging the cap, it's charging the inductor, which stores the energy in its magnetic field, then the inductor output charges the cap. Filter topology is LCLC.
Your link shows a cap input supply, by the way. Put a choke between the rectifier and cap and you get a choke input supply.
Ait, I think it is possible to place very large coil in front of capacitors in order to obtain constant charging current in form of sinewave.  The problem I can see with this scheme is size of the coil (huge inductance with low resistance) and the fact that voltage on the capacitor will depend on the load.  Voltage with load should be roughly 2/3 of peak voltage, but without any load it could climb up to 100% (peak value). I guess it should be possible in class AB amps to provide minimum load with additional resistor (if necessary).   Interesting concept, but I suspect seldom used because of the cost and size.  On the other hand high end audio is never practical.  Thanks for the info - I will find some articles to read on this subject.
[quote]Atmasphere made no big logical mistake - his assumption is valid, though the result of the technological evolution is by no means guaranteed. In other words, class D amps might get a little better and then exhaust their potential, or they might keep improving more and more with no end in sight.[/quote]

Exactly.

One can assume that since there is a 3rd gen out there, that there will be a 4th gen sometime too. This thread and others like it exist as proof that class D is still not a mature technology as the improvements that have appeared in just the last few years are made out on those threads and this one to be pretty profound. If the technology were mature, the improvements would be incremental, possibly taking a decade or more before the improvements accrued really meant something important.