Relocating power transformer in PS Audio GCPH

"But I doubt if I will go back beacuse the new noise performance is so much better."

How is the music performance?

Dhl, This is a really intriguing mod. We talked about our experiences with the GCPH on the earlier thread a couple weeks back. My own stock unit is sounding really good right now after getting the rest of my front end dialed in just right. I'd like to learn more and ask a few questions. Can you pm me at jswanson at hotmail dot com?

Thanks! Swanny

Sorry, correct pm is jswanson76109 at hotmail.

Rrog:

I can't comment yet as I am still putting my turntable/arm/cart together. I would not expect it to be worse than stock, however. The noise was such a big issue for me that I felt I needed to deal with it if I was going to continue consideration of the GCPH.

Swanny:

I'll email you further details. Too bad we cannot post pics on Agon. I can take some for you if you wish.

Thanks and yes, I'd love to see the pics.

I'd love to see pics too. Maybe another location for pics...
I have an Underwood modded GCPH and have no hum issues. Maybe the ERS around the PS section accomplishes some of the isolation that relocating the transformer accomplishes?
132,000uF!!!! That's a lot of capacitance for a little phono amp. BTW, I'm using it with a Bob's SUT, Denon 103R and Pass X0.2 pre.

Swanny:

I sent an email to your address. Did you get it?

For pics maybe I can post something on vinyl engine, if you guys subsrcibe to that forum.

M297904:

Yes, the outboard capacitance is about 2.75x the stock level of 48,000 mfd (which is also quite a lot for a pre-amp).

Re the Underwood mods, I could not really see what "input resistors" they were replacing, as all the passive components (except the power supply caps, diodes, and voltage regulators) on the input stages are all surface mount and you cannot replace surface mount resistors with leaded components. That is practically impossible. Unless they are going inside the GC modules themselves? There are four smaller electrolytic caps that act as bypassing caps for the IC pre-amp that I understand they may also be replacing.

Certainly any mu metal/mag shielding placed between that transformer and the circuit board will help reduce hum levels. But relocating the transformer will do more than any shielding can IMHO, as distance is your friend where field strength is concerned.

It's no coincidence that remotely packaging the power supply is practiced by a number of phono pre-amp manufacturers, including Byston and others. It's too bad that PS does not follow the same practice, but I understand their concern for cost (the Bryston is many times the cost of the PS Audio).

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?