[Hoots]

Do I need a power conditioner?  Any suggestions?

I Get a quick audio drop out when the thermostat on my A.C. turns on or off.  I don't get this when listening to my CD or DVD player. 

I have an external USB drive to a P4 PC with soundcard to pre/pro/dac.

[WGH]

Do you have a surge protector with battery backup on the PC? There is probably enough of a voltage drop to cause a glitch. Look for models that have automatic voltage regulation (AVR). AVR instantly adjusts both low and high voltages to safe levels.

Wayne