If you’re still following along from part 1, we’ve settled on restoring some aspects of the pedal while modifying others as we see fit. The first thing I did when I got the pedal in was completely disassemble it. This lets me evaluate the level of repairs required, the parts I need to order, and whether things are “worth it” because the eBay pictures might not match what you got.
Thankfully, the pedal was exactly as described. It wouldn’t work right now if you tried plugging it in because the very cheap open jacks used to replace the closed pcb-mounted jacks the pedal came with are: A) shorting against the PCB B) have broken wire leads C) binding the pcb in such a way as to short against the backs of the pots. My solution? Cut the jacks out and de-solder what’s left of the leads. That’s all getting replaced anyways.
Next I went digging through my box of screws for computers, amps, and pedals. I found exactly 6 perfect-fit Philips head screws in silver(yes, lucky). In the pictures I’ve seen they come with a variety of hardware, from slotted silver screws to black Philips to black slotted so any hardware is better than no hardware or having to buy hardware.
Once I had the hardware sorted, I gave the pots a look. The last Sovtek I got had a pot that would turn past the stops. Priors had pots that were sloppy, loose, and worn out. These have good rotation so I’ll spray them clean, slap some pot condoms on the back, and hope they aren’t scratchy when I’m done. FWIW, they tested at 80K on the ohmmeter which puts them on the ragged edge of 20% tolerance. I’ll let this slide as most pots are 20% and if I buy replacements I can say goodbye to the stock Sovtek knobs which also means buying three new knobs.
That leaves the circuit board. It is in great shape considering it had a hack job done to it. I didn’t initially notice that the battery tab was hacked onto the existing leads but sure enough … shrink wrapped hack job. I rummaged through my parts bins and found a switching 9v jack for external power or 9v battery. I also found a nice long new battery tab that will span the distance from the jack to the battery holder without needing spliced. I don’t have any 22uf caps lying around to replace the old one, but I have a ton of 47uf. Considering we’re now adding external DC, enlarging this cap will only help. Less stuff to order. Snipped the old leads out and removed the battery snap.
I made sure to check the circuit board for differences between the Green Tall Font V7C and the Black V8. There were different caps in the transistor feedback loops (470pf) whereas the Tall Font has 500pf. Additionally, the transistors and diodes were different which I expected. I have sets of those already so I don’t have to go hunting eastern Europe for them. You can find more information regarding these differences over at the Big Muff History – V7 to V8 page. I’ll share the schematics borrowed from there for visual reference.
Green V7C Tall Font:
Black V8:
I also took note of how the 39K input resistor was configured and we’ll be needing to replace it when it comes time to do the true-bypass mod. Expect instructions on this later. I keep a parts bin of common resistors so I didn’t need to order this one.
Finally, we come to the foot switch and LED. The LED is supposed to be glued in place, however the adhesive is old and had failed. I de-soldered the leads from the pcb and footswitch. I finished up the footswitch by de-soldering the remaining leads from the pcb and pots. It is a DPDT latching footswitch in a non-true bypass configuration. Since we’re going to true bypass with LED, we’ll be needing a 3PDT latching footswitch.
I now have my shopping list:
Capacitors:
500pf x 3
Hardware:
Stereo 1/4 enclosed jacks, pcb pin mount x 2
3PDT latching solder lug footswitch x 1
Unfortunately, I wasn’t able to get everything I wanted from one place. I went with Bitches Love My Switches for the hardware and Tube Depot for the caps. Even with paying shipping twice I managed to keep the bill under $20 and that included ordering a few items extra (because I needed those Breadboarding Is Not A Crime stickers).
Here’s the final product. I ended up selling this pedal for $140 (over $50 profit) and buying the reissue Sovtek muff and a ProCo Rat 2. I’ll be making changes to those as well in future posts.
cultofack 