whotat,
You say you "burnt out" the power supply module in your Penta speaker by which I assume you mean PCB1 (8002915) which contains part of the amplifier and the power supply.
When you say "burnt out" do you mean it went up in smoke and now there is nothing left of the board or do you mean it has an electronic fault which you may have caused ?
If the problem is in the power supply, then as it is quite a basic circuit it should be fixable.