VAC Preamp: Is my Phono stage failing?

My system is on two 20amp dedicated lines and all components are fed power from a AC regenerator that completely isolates the system from the wall power. I also have a hot tub in the back yard on its own separate 20a circuit.

I don't quite understand this. Do you have one AC regenerator or two? If it is only one, and all components are powered through it, how is the second dedicated line being used, if at all?

Regards,
-- Al

Sorry Al, I should have clarified. My two channel analogue music system is my first priority. The PurePower regenerator is on this system plugged into the first dedicated line.

The other dedicated line is feeding the home theatre system which I keep completely separate. Although they are the same room, when I'm listening to vinyl, all power to the digital HT system is off. I use two Panamax power conditioners on this system.

When I'm in critical listening mode, i even turn off the refridgerator, which is quite loud in our open-plan home. Now, if I could only remember to turn the fridge back on, I would get fewer of those looks from my wife!

Alonski, FWIW, I have a dedicated line and a power conditioner and have found that the sound is improved (opened up) on my VAC integrated amp if I go straight into the wall with the amp. I have seen a number of threads that back up the assertion that amplification performance is better going straight to the wall. I know it is a bit of a risk but I take precaution to unplug during storms or if I am away for extended periods. Also, as a last resort, I guess my homeowners insurance will cover me if there is a sudden and accidental surge that wipes out my VAC.

What remains a mystery is how this hum got into the signal path... Any ideas?

Yes, that does seem counter-intuitive and mysterious. The only thought that occurs to me is along the lines of what you were speculating, that the safety grounds for the two circuits are not completely separate (both physically and electrically) all the way back to the point where the safety grounds and AC neutral lines come together at the service panel. Conceivably that could result in low-level leakage currents that can be expected to occur between the tub's AC supply and safety ground to couple onto the safety ground wiring to the audio system, which would put it on the chassis of the components, from whence it might couple onto the signal path. The MC stage, of course, figures to be more susceptible to that than any other point in the system, due to the low signal levels and high gain that are involved.

Regards,
-- Al

Maineiac, Thanks, I tried having my Phi 200 amp direct to the wall and it sounded great. Then I tried plugging it into a Panamax power conditioner and it sounded like someone threw a wet blanket over the sound. Then i bought the Purepower AC regenerator and plugged the amp into it... WOW, it blew away anything I've heard from this amp. Surge protection of the highest order, clean power, lots of AC headroom for even more attack and a blacker background. A significant improvement from direct into the wall. But, to be fair, I'll A/B it again next time I move the 400 lb. armoire that's in front of the wall plug.

Al, I agree with your speculation on the pathway this rogue hum snuck through. I hope to have an answer on Monday when the electrician comes back.

Thank you both for your insights and help.
Alon