Wharfedale Pro PM 600 ±15 V Power Supply Rebuild

Essentially, all I had was the mixer panel, the case, transformer, and three heatsinks. I decided to remove the burnt PCB and build a new power supply for the mixer panel only. After building the power supply, I tested the mixer, and it worked fine. I fed the output from the mixer to my surround sound amplifier, and the sound quality was very good.

Here is the ±15 V power supply circuit that I built.

I was able to recycle the sockets from the original circuit, hence the wires from the transformer plugs directly to these. In this circuit, the voltage regulators are very good quality. The LM7915CT is a -15 V regulator by National Semiconductor, and it can supply up to 1.2 A. The LM340T15 is a +15 V regulator by Motorola. It can supply up to 1 A. This board also has power supply for the cooling fan, consisting of a small dedicated bridge rectifier and electrolytic capacitor.

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