amp builders: mixed mode lm3886??

[dschwartz]

hi all:
i´m toying with the idea of designing a power amp with a lm3886, but i´d like it to have a damping control..
for that, i´m not sure if you can make a mixed mode or current feedback with one of those chips..
any idea if it is feasible?

[brett]

Hi
the application note is quite extensive.  Anything in there?
I assume that you don't want to work from the tail end right back to the head, due to phase and gain problems, etc?
cheers

[Johan]

I asked pretty much the same question a few years back and got some good responces here.. http://www.diystompboxes.com/smfforum/index.php?topic=38331.0
..I never did run with it even though there are a few ideas I want to explore...look at Marshall Valvestate poweramps ( 8040 and 8004 for the slightly bigger chipamps) and the way the feedback is set up, for ideas..
johan

[R.G.]

Yeah, you can do current feedback, within reason.

It's that "within reason" you're going to worry about next, right? 

If you're just trying to raise the output impedance up to tube-amp-ish levels, it should work fine. Trying to compensate for oddities like crossover impedance, wire resistance, etc. can get you into oscillation problems.