2. amps-preamps
  3. 1069258983

Please advise - volume-variable buzz in spkrs

Introduced a new (used) tubed preamp into the system yesterday. Having had tubes before, I was prepared for a tube hiss, but what I got was a buzz that increases with volume. It is in both speakers and seems to be about the same level in each. It definitely gets in the way of the music and during a late-nite session could be heard even farther away than the listening position.
Nothing else in the system has changed. I use Chris VH power cords on the cdp, amp and preamp. I tried lifting the ground on the pre and amp (separately); tried a cheap 2-prong cable; no change. The HT comes through this system, so I disconnected that including the cable tv. No change. The only thing I haven't tried, I think, is changing tubes, and that's because I don't have replacements on hand.
Any ideas? I've been thru the forums here and on AA (but not fully; my DSL chose this morning to crap out as well!).
kck

Showing 2 responses by kck

kck OP
184 posts
 
Did a lot of experimenting, and found that I could eliminate 75% of the buzz by rerouting cables. There was a set of ICs touching and partly intersecting the path of a power cable. Lifting it in my hand reduced it quite a bit. As the rat's nest did not allow for too much tweaking there, I just moved components around.
There is still that 25% or so left. I will try more fiddling tonight.
Try that, Clydemetz!
kck OP
184 posts
 
Phild, that is interesting. I have the exact same symptoms, and in fact I did have an SS pre that had no hiss. What was the guilty item and how did you find it? Of course my amp would be different from yours but it is worth a try.
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