Uses for car stereo amp

[darryl]

Agreed about class D amps. I don't know if the amps I'm looking at are class D or not- but car amps never used to be class D. They were AB all the way.

My take on the design of an amp leads me to using a class D to supply voltage to the output transistors in a fairly standard amp, the common emitter type of design. Start with say 10 volts to the collectors, then maintain a fairly steady voltage across the output transistors as they swing up and down to supply the speaker signal. Class D could do this efficiently, while the amp runs in pure analog fashion. You could get away with using 50 volt output devices if you did it right.

[The Metal Butcher]

In a liquidation store the other day where they have several car stereo amps for sale. 450 watts stated power- no other descriptions that I could read. $15 each. They are new, in original box. I'm trying to think of any alternative uses for such a thing. Any ideas?

$15.

Buying things you don't need just because they are cheap is a logical fallacy. Not to say I never fall victim to that, but this is pound foolish.

[J Tiers]

The reasons I suspect it to be class-D include the following:

They seem to be new, or recent (per your description), and most recent stuff is, and has been for the last 10years or so. And you mentioned the very small heatsinks.

Class-D is actually cheaper now than analog.

The efficiency of class-D allows for a smaller and cheaper power supply, since the energy wasted by analog amps has to be supplied by something, and then rejected by expensive heatsinks. Which is another way in which it is cheaper.