System feedback coming thru speakers.....help

Lloydelee21, as improbable as it seems that an amp in both channels would do this with any input but not without, I think this is the only obvious test.

Tbg,

I hear you...i'm no techie, so just trying eliminate variable's the 'simple man's way'.

PROBLEM SOLVED!!!!!!!
Well, I finally spoke with Ed at CJ earlier this week and we took off the cover of the amp together (as the fuses are internal on the Sonagraph SA400). Sure enough, 2 of the 4 fuses were blown. once replaced, all is well.

I want to personally thank each and every one of you for your input, advice and direction in helping me solve my issue. Your direction allowed me to go to Ed with pinpoint accuracy on where "we" collectively thought the issue might be.
There is nothing more satisfying now than sitting in front of my system and listening, feeling the stresses of the day wash away. I truly love being a lover of music, the arts.....as a product of them growing up, and even a music major in college (before switching to business and finding my career in healthcare sales/leadership), music has always been core and foundational in my life. It is good to be us!
Thank you again, fellow Audiogoners!

Sincerely,

Jason Dvorak

Fantastic!!! Very glad was able to help...he really is THE MAN! Enjoy!!!

ok, one more question. I've blown a few fuses now ont he amp.....wondering if there is "dirty" power, and/or do I need a line conditioner/filter of some sort. anyone have any knowledge/experience in this area?