Attempt at an amp with a few watts

[akis]

I am thinking of making something like the below as an audio amplifier. I have done this circuit for headphones and it works OK (without the parallel transistors and without independent power supplies).

So as the circuit shows I am thinking of parallelising as many transistors as needed to keep Ic low and hFE linear. Then I will provide a separate PSU to those transistors. The driver stage will work of another, may be regulated, PSU.

As it is shown it is class AB but I could make it class A for a laugh.

What do you think?

[gaetan8888]

Hello

Look at this thread for a very good headphone amp;

Aspen Headphone Amp

Bye

Gaetan

[akis]

Hi, thanks fot the link. However I am not (thinking of) building a headphone amp, instead I am thinking of building a power amp. Perhaps a few watts to start with and later perhaps bigger.

What I was saying above is that I have tried this design as a headphone amp and it seems to be working well. There is no (global) feedback, there is no transistor swinging from rail to rail unbounded (I think this is called VAS transistor), there is no regulating the power supply one way or the other, ie no current mirrors or other active components. Instead the idea is to use separate power supplies (all the way back to separate transformers) for the current amplification stage and the voltage amplification stage. I have not tried that and was wondering if someone would immediately spot problems.

The premise is to be extrememly simple, no differential pairs, no feedback, no voltage regulating transistors. See how many watts I can get out of it.