Muffed Muff

[jimmy rocket]

I began posting this as a side note to the "show your pedalboards" thread, but I thought I'd move it here to avoid hijacking that thread.

Long story short - I decided to rehouse a russian big muff pi into an EHX nano sized box. Upon first moving the contents, the pedal worked like a dream. I took everything out of the box to finish it, and after replacing all the contents it still worked. so I tightened all the bottom screws and went to put it on my pedalboard, and nothing.

Well, the LED lights up, but that's rather unimpressive when the pedal is sitting there like a lump.

Having little electronics experience I thought I'd post it as a challenge to see if any of the more experienced members of this forum see any glaring errors on my part.

I named her the Fuzzy Kitten (in Cyrillic of course). Here's what she looks like:



Here's a shot of the PCB traces. All test ok for continuity so I know it's not a broken trace.



Here's a shot of the off-board wiring scheme (note I did not desolder any of the pots so I didn't include them in the pic):



and finally a shot of the DPDT switch. The wiring scheme is as manufactured and is as such:

Top Left - goes to center of "sustain" pot
Middle left both grounds - to either side of board output
lower left - to LED(- side)

Top right - board input
middle right - board output
bottom right - to middle lug of "volume" pot



I really just want it to work, and while I'd be elated to figure it out myself, I'm clearly not competent in this arena. I'd even pay someone to correct the issues at this point, but I wouldn't even know who to send it to.

So, any theories?

[cheapbasslovin]

Maybe you need to insulate the circuit board/ pots/ switches from each other and the casing. Does it work out of the case now?

[rcubed]

Check your ground wires. Are you running this off of a battery? I also don't get how you have a wire going from the footswitch to the center of the sustain pot. That doesn't make sense.

[rratajski]

Did you follow the rehouse steps from anywhere or did it on your own?

[jimmy rocket]

Originally Posted by cheapbasslovin

Maybe you need to insulate the circuit board/ pots/ switches from each other and the casing. Does it work out of the case now?

It no longer works in or out of the case. I did try insulating individual components at first, but it didn't seem to do anything.

Originally Posted by rcubed

Check your ground wires. Are you running this off of a battery? I also don't get how you have a wire going from the footswitch to the center of the sustain pot. That doesn't make sense.

I was running it off of a boss power supply connected to it by one of those power supply to 9v adapters.

The wiring on the switch is identical to how it was when I got it. It doesn't make sense to me, but I just assumed it was some sort of DPDT wiring scheme of which I was unaware

As far as ground wires go, when I opened the black muff there was one ground wire bolted directly to the chassis. (this was connected to the second of the ground wires going to the center position of the switch) Upon rehousing I did not connect this wire and it worked fine. I have since re-established that connection, but it didn't do anything.

Originally Posted by rratajski

Did you follow the rehouse steps from anywhere or did it on your own?

I mostly did it on my own. I wasn't looking to alter the circuit or make it true bypass, so I simply desoldered the input and output, re-soldered them to stereo and mono jacks (respectively) and put everything in a smaller box.

[jimmy rocket]

This story has a happy-ish ending.

Ok, so to rule out circuit board issues I completely reconstructed the pedal as stock in the original housing, and it purrs like a nasty kitten. (i.e. it works)

by process of elimination, the only thing I can see that's different is that I replaced the stock plastic jacks with metal ones, and they made contact with the case, presumably causing it to ground out.

I'm leaving the muff as is and I plan to use the housing for a GGG build.

[rcubed]

Originally Posted by jimmy rocket

This story has a happy-ish ending.

Ok, so to rule out circuit board issues I completely reconstructed the pedal as stock in the original housing, and it purrs like a nasty kitten. (i.e. it works)

by process of elimination, the only thing I can see that's different is that I replaced the stock plastic jacks with metal ones, and they made contact with the case, presumably causing it to ground out.

I'm leaving the muff as is and I plan to use the housing for a GGG build.

Change up the tone stack on the GGG circuit. Add a mids knob if you're feeling brave.

[jimmy rocket]

Since I already have the Russian Muff, and it does exactly what I want it to do, I've decided to switch gears to a TS808. I bought the GGG ITS8 kit, and it's on the way.

Here's the re-designed (yet still empty) case. I couldn't resist mocking it up.

[rratajski]

I recommend modding it for bass. It's THIN, even through an SVT head!

[jimmy rocket]

Originally Posted by rratajski

I recommend modding it for bass. It's THIN, even through an SVT head!

I was intending to do the AMZ fat mod. Is there another particular bass mod that I should check out?

This will also probably see some double duty use with a Tele and a Blues Jr.

[TrevorOfDoom]

you could easily mod the 808 to BassDrive specs...

[jimmy rocket]

Originally Posted by TrevorOfDoom

you could easily mod the 808 to BassDrive specs...

any links to instructions for this?

[TrevorOfDoom]

Originally Posted by jimmy rocket

any links to instructions for this?

i found them in the BYOC forums, under known mods for the overdrive.
check there, or i'll see if i can dig them up. it was really rather easy.

[jimmy rocket]

Ok, here she is:





This is the GGG circuit (with additional clipping selector switch) The only mod I did at this point is the asymmetrical clipping mod.

Sounds beefy

I see more builds in my future.