It's very Big Muff like in tone, but seems to have a bit more clarity in the notes, and no Fuzz control, just Bass, Treble, and Volume. In my search for the schematic I found that over time there's been 3 different versions, so I made a layout for each, and then found that a few years ago by Miro actually made a layout for the later version. My layouts are a bit more compact, has less cuts & jumpers, and I put the CLR for the LED on the board, so I thought I would still post all of them, since while they have the same feel, each sounds a bit different.
Also, through my searching I found some mods people have done, and made a massively modded layout as well that I'll post later with a description of it all.
The video compares the stock vintage unit to a clone made by Brad at Creepy Fingers. Not sure what the extra pot does, but since it's full CW I can only assume it's a Fuzz Pot.
2 Knob Version
- You may need to adjust the 2 10k resistors to the Collectors of Q1 & Q2 to bias the transistors right and have it sound good.
- Since BC149's are hard to come by, although I've seen them on eBay, you may want to try the usual suspects with higher gain. So transistors like 2N5088/2N5089, MPSA18, BC109, BC108, etc.
- For the 2 knob version you may want to change the 2uF caps to 10uF caps like the later version.
- For more fuzz remove the 100k or 1M resistor parallel to D1 & D2.
- I left out the usual 1M pulldown resistor as in all the videos I heard I didn't hear a pop from the vintage unit, so I felt it's not needed, you can always add it on the switch or just add an extra column.