trinityamps.com

Hi all
I've posted this question on a couple other forum sites so I apologize if you've seen it else where, I'm just seeking a range of opinions before I dive in to try and fix this.

A couple years back I built a very sweet S-III and love it! (Its really a great little amp) -- But recently it's developed this significant noise/buzz. It sounds like a ground issue to my amateur ears, maybe the jack on the first channel as it persists when I turn up that volume pot even without a guitar plugged in; the TMB channel seems fine when unplugged but when there is a guitar plugged in (in either channel) both channels have the buzz. I was wondering how exactly I should go about trouble shooting it. I made a video as an example of whats going on with it which explains maybe better then I am here.

http://www.youtube.com/watch?v=oeQtgFO-xVM

Someone over at 18w.com suggested it may also be a bad tube, but I'm not even sure how to go about checking that. They all seem to light up. Some people on this forum were a great help when I was building it so I thought I'd check back for advice on this.

Cheers
/m

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http://thepopmodule.com

It sounds like E M interference from the wiring in the new apartment or from a computer or florescent light etc. It comes from unshielded guitar cavity and in your case some un shielding in the amp as well on the normal channel. I noticed in the video that when you move the guitar around the hum would change (less or more) depending how the guitar was oriented. The amp should respond the same way. Try moving the amp around the room. Maybe turn the amp so that it is perpendicular to the wall (at a right angle) or move it to the center of the room and see if it reduces the hum. I get that same thing as well in different locations of my house. Touching the strings or bridge affects it as well as your body provides some grounding/shielding so as to reduce it somewhat. As far as the normal channel goes it seems that maybe the ground on the input or on the shielded cable from the input to first tube may have come loose.

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Les

http://www.soundclick.com/unimind

When you put it in a cabinet, did you shield the amp with aluminum sheet or aluminum tape on the bottom? This can make a big difference depending on where you are playing it. Also, try in in another room too.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

What is it like with the guitar unplugged BTW?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps