PedalBuilder
Well-known member
Despite the Tone Bender name, it's definitely a Big Muff. It's similar to some of the Ram's Head-era Big Muffs, but with a few differences. First and foremost, Q2 has no clipping diodes, which increases the output volume significantly and results in what sounds like heavily asymmetrical clipping. Second, the tone control is wired backwards, and uses a log taper pot. Third, there's an extra 100nF capacitor between the Q3 collector and the tone stack. Other than this last change, you can easily build one of these on a standard Big Muff board by omitting the diodes and their coupling capacitor from the second gain stage and using a C-taper pot for the tone control (or an A-taper pot with lugs 1 and 3 swapped, if you want the backwards tone control of the original).
I didn't have a C100k potentiometer on hand, so I went with an A100k with the connections of lugs 1 and 3 swapped. To add the extra capacitor, I cut the trace on the back side of the PCB that connected Q3C and the Tone Stack, and jumpered it with a 100nF capacitor that I tacked on to the back of the board. Supposedly the Supa Tone Bender works really well on bass. I don't have one currently, but it does have more low end than any non-Russian muff that I've build.
Transistors are BC549B and 2N3904; diodes are 1N4150 for a little extra clipping and compression. I skipped my usual I/O boards because I had some extra @StompBoxParts audio jacks lying around and all of the components are rated for well over 18v. These jacks have a set of teeth that help hold them in place, which is very thoughtful feature to have. Reverse polarity protection is provided via an offboard 1N5817.
Inside:
I didn't have a C100k potentiometer on hand, so I went with an A100k with the connections of lugs 1 and 3 swapped. To add the extra capacitor, I cut the trace on the back side of the PCB that connected Q3C and the Tone Stack, and jumpered it with a 100nF capacitor that I tacked on to the back of the board. Supposedly the Supa Tone Bender works really well on bass. I don't have one currently, but it does have more low end than any non-Russian muff that I've build.
Transistors are BC549B and 2N3904; diodes are 1N4150 for a little extra clipping and compression. I skipped my usual I/O boards because I had some extra @StompBoxParts audio jacks lying around and all of the components are rated for well over 18v. These jacks have a set of teeth that help hold them in place, which is very thoughtful feature to have. Reverse polarity protection is provided via an offboard 1N5817.
Inside:
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