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DIY Stompboxes => Building your own stompbox => Topic started by: kimelopidaer on October 06, 2010, 06:32:09 PM

Title: Russian Big Muff True Bypass...Loud hum and no sound unless you engage the pedal
Post by: kimelopidaer on October 06, 2010, 06:32:09 PM
Hi. I am handy with a soldering iron but less so with circuits and diagnosis. I would appreciate any suggestions here, and I hope i'm in the right forum.

I have a black russian big muff, and recently had it true bypassed.
The unit causes an unlawful hum either either bypassed or engaged.
It only allows signal when I engage the effect, and even then I can only hear the distortion below the hum.
When I bypass the effect, I lose all sound but this crazy hum.

I've opened her up, and I don't see anything visually suspect. The battery is fresh and the ground wire is screwed one of the feet on the back of the effect casing.

Is this likely a problem with the footswitch?
If a component on the board were blown, would there be sound at all?


If I plug the cables in backward, I get a standard bypass sound, until I engage the effect, and the pedal is muted.

alright,
I'll leave it with you all.
and
Thankyou


Title: Re: Russian Big Muff True Bypass...Loud hum and no sound unless you engage the pedal
Post by: ianmgull on October 06, 2010, 11:29:01 PM
You may have the switch wired wrong. What bypass scheme did you use? Can you post pics?
Title: Re: Russian Big Muff True Bypass...Loud hum and no sound unless you engage the pedal
Post by: kimelopidaer on October 07, 2010, 12:20:02 PM
The true bypassing was not done by me, however it had worked fine for the last while since I've had it again. I connected the pedal to my setup this morning, this time without battery. I get a very weak guitar signal, dominated by the much louder hum.

All the switch wires appear intact.

Thanks for taking a look.


(http://imgur.com/5rYf5.jpg) (http://imgur.com/5rYf5.jpg)