Power problem causing drop-out in surround sound

I recently moved into an old house (78 years old) and had 4 dedicated 20 amp circuits for audio - home theater system installed by a licensed electrician. My Sherwood Newcastle AVP9080 surround sound processor now drops out for a period of 1-3 seconds anytime anything is turned on or off throughout the entire house. The house does have updated electrical service. I have tried to isolate the problem down to an individual circuit by turning each circuit off individually to see if the problem still occurs with no luck. I did not experience this problem at my previous house (even older). I have had my voltage coming into the house checked by the power company and it falls within acceptable range (123V) and I have tried to using a multimeter to measure what happens when something is turned on and off with no indication of any problems. Can anyone tell me what to do at this point as far as things to look for, what other kinds of test equipment to use, etc. This drop-out only happens on digital inputs. On analog inputs, there is no problem. Also, my DAC for my two channel system does not experience any drop-outs.


I had the same problem a few years back. I found a couple of solutions to work. The best solution is to use a good quality isolation transformer in from of your a/v system. I build my own using a Plitron 3000 watt medical grade transformer.

Next method is to track down all the culprits in the house. Place a bypass capacitor across the load at the location of the problem. This method worked good for me on certain situations (lighting).

Forget the suggestion of power conditioners. I tried everyone from API to Tice to PS Audio and everyone in between. The only thing that helped was the isolation transformer. A balanced (60/60) would also solve the problem. Bpt makes some very good units for the price.

Hope this helps...
Alan Maher
Off the top of my head, sounds like there may be low voltage arcing SOMEWHERE in your wiring system; affects digital, computers, etc., more than resistive or motor loads so its hard to pin down, i.e. a light plugged into the offending outlet might not dim down enough to notice a problem.

A good place to start is to check that the phase conductors in your panel are tight with no insulation on the lugs. You have to be able to see a little copper underneath.

Also, check the new wiring - some electricians do not strip back new wires far enough; they push them down to expose the copper, install them, and then the plastic jacket pushes up and dislodges the copper connection if they aren't tight. Check those on the new circuits, especially the neutrals (white). Also, take your multimeter and check the voltage drop across the breakers (careful!!). Good luck, these problems are a royal pain.
Thanks for your responses!