Relocating power transformer in PS Audio GCPH


I just recently completed a project to relocate (or actually disable) the torodial power transformer in my PS Audio GCPH phono pre-amp.

I built a separate outboard power supply with a similar torodial transformer (so I could leave the stock one installed but disconnected) that has 132,000 mfd of capacitance. I run the V+ , V- and Gnd busses up to the GCPH and feed them through the chassis using an Amphenol connector, and run wiring from the connector to a molex style three pin that matches the connector on the original GCPH transformer. I removed the IEC AC connector (and associated circuit board) and mounted the Amphenol connector to a blind off plate that mounts in place of the IEC.

After the modification, the hum (60/120/240 Hz) noise component is completely gone. Much quieter on the 60 dB and 66 dB gain settings. I can also use more of the volume control than before.

This setup allows me to go back to stock if desired, as I did not disturb the position of the PS Audio power transformer (which is critical). But I doubt if I will go back beacuse the new noise performance is so much better.
dhl93449

Showing 1 response by rogerstaton

Is it possible to let me have copies of your photos of your GCPH mods please? My email is rogerstaton@yahoo.co.uk.

I have 2 GCPH phono stages and thought of the possibility of using the power supply in one to power the other? Would just removing the molex style three pin connections from each then extending one and connecting it to the other work?