madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: sgmezei on January 21, 2012, 09:13:53 PM

Title: Working on a Big Muff (Green Russian)
Post by: sgmezei on January 21, 2012, 09:13:53 PM
Alrighty, so a buddy gave me his Green Russian BMP to replace the broken battery snap. No problem I say. I want to put in a dc jack on the back for our usual wall wart setup.

I know there are a ton of versions and I came across a thread stating some of them were Positive Ground. I am frustrated going through a million threads so hopefully I can get some help from my Comrades here.

Is this a positive ground effect? It is made in Russia and has the massive green enclosure. I measured the positive and negative on the board and it reads normal to me. I put red probe on red battery snap wire and black on black. Even the PCB has + where the red wire is and - where the black is.

I just don't want to mess it up. It is a good buddy's.
Title: Re: Working on a Big Muff (Green Russian)
Post by: jkokura on January 21, 2012, 09:46:13 PM
Positive ground? Not likely. Perhaps PNP instead of NPN, but not positive ground. At least I've never read that. Got a link?

Jacob
Title: Re: Working on a Big Muff (Green Russian)
Post by: sgmezei on January 22, 2012, 12:50:27 PM
Okay now I cannot find the article which states it is Positive Ground.

So I am going to go ahead and wire it with the normal madbean wiring method.

Anybody see any issues with this? Jacob?
Title: Re: Working on a Big Muff (Green Russian)
Post by: jkokura on January 22, 2012, 05:41:36 PM
nope.

Jacob
Title: Re: Working on a Big Muff (Green Russian)
Post by: sgmezei on January 22, 2012, 10:55:03 PM
All is well. Worked like a charm and was totally normal. Thanks for the input Jacob.
Title: Re: Working on a Big Muff (Green Russian)
Post by: Scruffie on January 22, 2012, 11:10:49 PM
There was one model of the Big Muff that was positive ground, wasn't a Sovtek though.

The positive thing probably comes from the fact the old phono DC jack sockets they used were wired for positive tip, not ground.