interesting amp concept (soon to be reality)

So in a class I'm taking now I have a design requirement which is in groups and my group has taken it upon ourselves to build an amplifier. What kindof amplifier you say?

Well.......

The idea is that of an X-like amp....kindof....but with modulated power rails (input signal feeding class D amps whose output are these rails with a DC shift) so that we're never dissipating excessive heat in the output stage and can build a very powerful amp.

So basically a traditional diff pair as an input stage and to act as a converter to balanced for unbalanced inputs (will offer both), followed by another diff pair with supersymmetry through to a folded cascode and a complementary push-pull output stage with the modulated rails

Oh, its also going to be integrated, so relay switched inputs and relay switched ladder attenuator too.



Yes, we are crazy to attempt this (have 3 more weeks and its still at a very loose schematic stage)......there are 3 of us......


Any comments?
 
Congratulations!!!
....... you've reinvented the basic concept of Carver's up/down coverter used in his Sunfire, etc... amps, and by others.

If you want to bootstrap the power rails off the audio signal, why are you attempting to do it with class D amps, rather than the analog amp itself? If you're building a class D amp, why do you want to complicate is with a complementry output stage? Worst of all possible worlds?
Its not going to sound any better that the class D amp.
 
The idea was that the class D amp would not have to be very good at all as "in theory" any distortion in it would not get through to the output.

Are you suggesting taking the output of the complementary stage and using it to form the rails?? (I'm tired and thinking how this could be possible.........)

Wouldn't you need seperate analog amps which would again be horribly inefficient for the rails?

But thankyou very much for your reply......I look forward to hearing more :)
 
so bashaudio is basically what we were trying to do before......

I VERY much like this idea of bootstrapping the rails to the output of the analog amp though.

I can just use the amp output to shift the ground point of the rails up and down....... (can't believe I never thought of this before)......

Anyway, thanks!

This is going to be an interesting exercise.......
 
argh, no I can't......I was being retarded, obviously then I'm just going to shift the dissipation to another area......the only way to truly make this efficient is to control the rails through some form of switching amp.

The distortion of that stage won't, however, get through into the output......this should work pretty well.