WT300 buzz / hum issue

[bthrem]

I purchased a used WT300 last month and am experiencing a buzz / hum issue. I put a new Ruby tube in it hoping that would cure the issue but it hasn't. Basically the problem is this:

When I turn the unit I can hear an electronic hum sound, like transformer hum. That sound, along with a slight buzz, can be heard on every output of the amp (tuner, DI, loop send, headphone, speaker). Obviously it is most noticeable on the headphone and speaker out. This sound can be heard on the headphone and speaker output even with the volume control all the way down - in fact it really doesn't get louder when turn the amp up.

It seems like a weird grounding problem or something to me. Any ideas out there? I'm OK with electronic troubleshooting if guided towards items to check.

The amp sounds fantastic otherwise!

 

[slareman]

I have a similar problem and posted here about it a few months back...very helpful responses, but basically I'm going to have to take it to a good tech to get things straightened out.

 

[bthrem]

Looked at that post. I'd say I have the exact same issue as you. I take it you haven't had it repaired yet?

 

[bthrem]

I found the source of my issue to be the green ground wire that comes off the effects loop / DI / etc connector on the preamp board. As I moved it around within the amp, the buzz in the output signal would become intense to nearly non-existent. It seems this wire is very susceptible to various electric fields generated within the amp. I found an optimal location and taped it in place. All is well now.