I am having a problem that is driving me crazy. It began when I hooked up a 15" driver to my left main channel to run some test tones (building DIY subwoofer). I realized I had a pronounced hum. I put my front speaker (10 plus year old B&W 2004) back on - realized there was a hum there also.
So I researched ground loop hums - possible culprits include cable TV, wrong polarity of plug, etc. After confirming the polarity of my outlets with my polarity tester, I proceeded to disconnect cable, etc.
In the end, I was left with my receiver (old Sony STR-D1090) and only my speakers. I removed all other connections to my receiver - EVERYTHING. With the volume at listening levels, there is an audible hum a few to several feet away from all speakers, although not very loud. I hook up the 15' driver - slightly louder hum. Even my rear QS8s have a hum from a few feet away. The receiver is grounded to a grounded outlet, but still there is a hum.
Note, no other funky appliances (like a bank of flourescent lights) are on in the house. The house is only 12 years old and the wiring is solid.
Is it just that my receiver a piece of crap? (yes is the default answer, but is that the problem?)
Or is this normal?
When nothing is being played through the receiver, should any hum be heard from speakers?
Any aid for my sanity will be greatly appreciated.
Pete
