Once again I am rebuilding another amplifer this time with a TDA7394 Power Amplifier board. I picked up theis fried amplifier at a Hmfest from a friend for like $10 for the poweer transformer. I tested the output transistors and all but one were shorted. So I decided to rebuild it with a dual TDA7394 amplifier board for $22 on eBay. The power transformer is 60 VCT so the rectified power is + and - 42 volts DC. That is a little high for the IC but within its specs. It should deliver 100 watts per channel into 8 ohms without any problems.
Here is the old circuit board. The preamp seemed OK so I decided to try to save it.
So I cut the old circuit board in half with a hand saw.
This is the new power amplifier board, it is a lot smaller than what it replaced.
Here is the finished amplifier. All it is missing is the power on LED and a shielded audio cable from the preamp output to the RCA jacks on the back panel. The preamp had a slight buzz in it, I don't know why. Perhaps better shielded audio cables would help.
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