Soviet Big Muff - New enclosure problems.

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narghile
Posts: 5
Joined: 06 Jul 2009, 15:50

Post by narghile »

Hello everyone,

I have a new model Soviet Big Muff that I transfered to a new case and now I can't get it to work again. If I plug the power cable in, the input jack cuts out. I get no sound in bypass or when it the effect is switched on. It's just like the input gets muted. The pots still change the sound of the resonant "hum", so I gotta have it almost right. If I unplug the power, bypass works as it should.

I loosedly followed this image:
Image

This is my build:
Image
Image
Image

When I plug it into different 9v wall worts I get different results. A 300ma kinda works but I get self oscillation. I've checked the connections and tried about everything I can think of. I posted here as a last resort. I just want my muff back.. :cry:

So can any of you effect gurus find the flaw in the circuit?

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azrael
Cap Cooler
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Post by azrael »

Are you sure you've cut the traces right?
Is anything from the power shorting to ground or to the enclosure somehow?

narghile
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Joined: 06 Jul 2009, 15:50

Post by narghile »

That's one of the things that is me throwing me off, I didn't have to cut the trace. This is a 'new' big muff with the trace already cut, hell it's not even there. This version already had true bypass when I started, and none of the diagrams out there have this updated configuration.

Does anyone out there have one of these new muffs that they can post a picture of?

I'll post the reverse side of the circuit later today.

dune2k
Breadboard Brother
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Post by dune2k »

Did you try the muff outside the enclosure? There are some spots where the PCB _might_ touch other components.
Also your output jack isn't properly grounded and there are a couple of soldered spots that don't look good (eg on the foot switch, brown wire).

Try building an audio probe (google helps). Maybe you'll find the error(s) with it. :)
JOHNO wrote:P.S Great pedal for playing 70's porn music.

narghile
Posts: 5
Joined: 06 Jul 2009, 15:50

Post by narghile »

Thanks for the reply, and yes I do have an audio probe. I guess i'll just have to spend more time poking at it. You know the main problem is that when you plug in the power the input jack cuts out, I guess this is where I should continue exploring.

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JRC4558D
Posts: 22
Joined: 03 Feb 2010, 11:47
my favorite amplifier: Vox AC-30
Completed builds: Sola Sound Tone Bender MKI 1965, Electro-Harmonix Pulsar, Mu-Tron III, Lovetone Meatball, Wolly Mammoth.

Mods: Small Stone (Frankestone), Rat (Tri-diode switch plus resistors, caps and CI mod), Dunlop Cry Baby (Caps and resistors).
Location: London, U.K

Post by JRC4558D »

Hi mate, I am pretty sure that you haven't got any room there in your box for that PCB, I guess your case isn't enough high, your 3PDT will crash your PCB or any of your components so be carefuly. Anyway try to keep all clean you know, write down what you'll be doing and stick yourself to that, I advise you that try to use this circuit for your 3PDT Image . A good idea should be to draw your own schematic having there your PCB with potes only and then add the 3PDT and in/out jacks, DC in, LED and battery clip...
I hope you solve your problem soon.
Good luck mate.
cheers

narghile
Posts: 5
Joined: 06 Jul 2009, 15:50

Post by narghile »

Thanks again every one for you help. I got it last night. I had room, just had to figure out the puzzle. :applause:

I hope anyone out there trying to the the same with one of these new muffs can fund this post. If i get around to opening it back up ill snap the final wiring gut shots.

bjlevine
Posts: 17
Joined: 30 Jun 2010, 15:42

Post by bjlevine »

So what did the problem turn out to be?

narghile
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Joined: 06 Jul 2009, 15:50

Post by narghile »

It was just a short somewhere. :slap:

After tediously inspecting the circuit over and over, it just started working.

The new enclosure fits perfectly on my pedalboard.

Thanks everyone again for your help! :applause:

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