Buzzzzz problem

[jandl100]

I recently sold my Bel Canto PRe3 preamp to a nice seeming guy.

All was well until this morning when I got this message ....

I've swapped around some leads this morning, so that, for the first time I'm using the balanced input, which is working fine. As was the phono input when I used it before. The sound is fine. The problem that I'm now having is, with the xlr's connected, when I try to connect any of the phono ins, I'm getting a very loud buzzing on all of them. I've tried selecting the appropriate input on the display, and using various sources, but without anything affecting the resultant buzzing sound.

It worked fine for me.
Suggestions anyone? (I suspect a grounding issue in his system somewhere).

Ta. :)

Here's a pic of the rear connectivity ...

http://i.imgur.com/83poe6E.jpg

[Audio Al]

Is he trying to connect with things powered up :eek: That causes loud buzzing

[Barry]

Without doubt it's a grounding problem. I suspect there might be a ground loop formed with the now-used XLR input and the RCA inputs (and possibly with the mains earth connection). Would need to know the exact configuration of the system to be able to advise further.

[RothwellAudio]

He needs to give a much more detailed description of the problem to identify a likely cause.

[jandl100]

Thanks folks.

I don't think he is an AOS member, but I have sent him a link to this thread.
Maybe he will join in with some more info.

[jandl100]

Just to close this off, I received this msg this morning ...

Hi Jerry,
Just thought I'd drop you a quick line to let you know that I have resolved the mystery of the hum! I think it was an RF interference problem which was somehow caused by a petulant unshielded solid silver digital interconnect which, I remember now, had actually been slightly problematic in the past. Anyway - replaced it with an old Chorus 2 as a temporary measure and all unwanted noise was removed along with it without further ado. Sorry it's taken a while - I've been away for three weeks, or so.
Very much appreciate your help in trying to identify the cause of the problem.
With best wishes,

[vintage60]

Jerry

I have Bel Canto M300 mono blocks and once when I tried to connect RCA plugs to them whilst they still had the XLRs attached, there was a loud pop and thereafter a noticeable buzzing noise. I opened the case and it turned out to be a blown fuse.

Likewise, when I was swapping out speaker cables and rca cables and accidentally dropped a rca cable metal plug onto the banana plug at the end of the speaker cable, the fuse blew and there was some buzzing noise. A new fuse fixed it and all the buzzing went away.

So I've experienced buzzing on two occasions from two different reasons and each time it was the fuse.

If your buyer is reading this, he should check the fuse as it might be as simple needing to replace it.

Best,

[jandl100]

Thanks Thiha - but it's sorted now, see the post before yours!

[vintage60]

Yes, I see that now. Glad it got sorted without too much trouble for you. Phew!