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).
