Hello,

I recently purchased a Vintage big box Deluxe Big Muff Pi.
PCB marked: E3054C (short circuit board)
Version: Parallel/Series Switch, Blend and Comp Outputs.

The model I have is 240v (with 3 pin AC cord).

I would like to convert this to 100V AC input (Japan) OR DC power.

Has anyone converted their similar unit to a different voltage or supply type?

At the moment the unit produces some fuzz sound using 100v however the compressor circuit simply distorts at low volume.

I could change the internal transformer, however I would need to know the operating voltage of the pedal internally which in the current circumstances I cannot test. (Assuming the current transformer steps down to a ratio – 240v to X, rather than ANY input voltage to the required voltage?).

Thank you for any help and experience you can provide!

I have the Sovtek Deluxe Big Muff Pi, which is just a deluxe version of the green Russian Big Muff. It’s very close to the Deluxe Big Muff Pi that you are looking at, with a couple of minor differences.

I got the Sovtek because that was the one they had at the store I went to. I would have happily got the regular Deluxe Big Muff Pi if they’d had that one instead.

Yes, it is bigger than a regular Big Muff, but the noise gate and mids section make it well worth it to me.

The short answer, this will probably burn your pedal.

There are 4 important things to look for when buying a power adapter.

1- AC/DC

If a pedal works on DC give it DC, if it works on AC give it AC. If you mix these up, you’ll fry your pedal. A high percentage of pedals work on DC, but you know, it doesn’t hurt to check.

“⎓” =DC

“⏦” =AC (the line can be above the “~” too or there can be no line at all)

2- Voltage (V)

The voltage of the power supply output shouldn’t be greater than the voltage pedal needs to operate. If it is, this will result in a fried pedal and an unhappy OP. Most of the guitar pedals out there work on 9VDC, however; there are quite many pedals requiring 12VDC, 18VDC, 9VAC -and some old circuits work on 24VAC- but your Big Muff needs regular 9VDC.

3- Amperage/Current (mA)

If a pedal says it needs 100mA to work yea give it 100, but you can give it 1000 too, it’s fine. Your pedal will draw the amount it needs, it won’t damage the pedal if you supply it more than what it says. Just don’t give it less, it will be unhappy and not work properly.

4- Polarity (the dot in the semi-circle with “+” and “-” next to them)

Polarity is where the positive and negative connectors are on the plug. Pedals use barrel plugs and there are 2 conductors on them, one on the outside of the “barrel” and one on the inside. Lucky for us, again, most of the pedals use center negative polarity and so does yours.

The problem with the adapter you sent a photo of is that it is center positive where it should be a center negative to not fry your pedal.

Your pedal needs 9VDC, 7mA center negative power to work.

If you have any more questions, I’d be happy to help.

• This reply was modified 2 years, 7 months ago by billfoster.

@BillFoster:
The Sovtek Deluxe Big Muff Pi is nowhere near what he’s looking at, which is a vintage big box (opamp version) Big Muff Pi with attached power cord. See image below.

@fuzzbuzzfuzz:
Analogman can probably do a conversion. He does a similar conversion for the Deluxe Memory Man with attached power cord. https://www.analogman.com/
If you want to go the DIY route, a better place to ask and get detailed instructions is probably https://www.diystompboxes.com/smfforum/index.php?board=2.0