Sugden PowerSupply problems.

I have been having some issues with my Sugden A21a Int amp recently that have made listening to it practically impossible.

My problem is that whenever there is a voltage drop of 1 volt or more in the house (appliance turning on) the Power Supply makes a clicking sound and the Amp shuts off for about 10 seconds.

I have checked the house wiring and it all seems to be within spec. The local PoCo considers anything up to an 8 volt drop within spec.

I have spoken to a couple of electrical engineers who suggest the problem could be a marginal power supply in the amp. Their recommendation was to hookup a scope to the Power Rail and watch for ripple. They suspect it is a bad Filter Capacitor.

Just wondering if anyone here has run into anything similar or has any ideas before I take it in and start spending lots of money getting it repaired. I have already taken it in once and they could find nothing wrong with it, however I doubt that this is something they checked and they have very stable power at the repair shop.

Thanks for any input,

I'm now guessing that the ripple is probably dipping below the clip level of the regulator, thus causing the power to clip. I will be taking it in soon I hope, but if anyone has any other ideas let me know!