Limited edition Red "Army Overdrive" Mud
This one came about over me being a "little" obsessed with this little fuzz circuit. As most of you know I make clones of my favourite vintage versions as well as some "special" ones like the Fuzz Munchkin, the Seaweed and a few crazy OEM and early versions just to keep things interesting.
The Civil War version of my Big Muds is always my on again/off again favourite version along with the Ram Head as both of these have distinctly different flavours while keeping the clarity and harmonics of a great BM. Like all (or most) of the BM circuits, they sound and behave like a BM but some versions have different qualities that work best for some people and once you find THAT one, that's it.
I had been looking around at some of the early versions of the Civil War and I've always been intrigued by the version known as "the Red Army Overdrive". These were first made around 1990 and were called the S0vt*k Red Army Overdrive.
I managed to track down the key components through a friend who makes pedals and initially only had enough to make 1 pedal. I just wanted to try it out and see if there was a difference to the tone and if so, was it good ? The main components that were needed for this version were the transistors, although transistor type has shown to not make a huge difference in tone in a BM circuit and the diodes. Both were long out of production Russian versions and I had tried my typical component places with no luck. Because I was being "a nerd" and wanted to do it properly I figured if I can't get the parts, I just won't do a clone.
Like all BM versions there are at least two "different" versions of the RAO with slight differences in values and components so I decided to go for the second version which had a little quirk that I liked the idea of. I managed to get 4 of the ORIGINAL NOS Russian KT3102E (green and white dot) transistors as were used in the original. These are THE ACTUAL transistors used in these versions from back in 1990.
The next component I needed was the (more) important ORIGINAL NOS Russian KD522 Diodes. Both of these components on paper are VERY similar to replacement parts available now but any pedal knows "on paper" doesn't always translate to "in ear"
So I built a few circuits with these components and more common components as "test" versions to hear the difference these parts were actually making to the tone. The other "quirk" I mentioned was a strange thing that this version used where caps were run in series in the feedback stages of the first three transistor gain stages to achieve a value that may not have been available to them at the time. It's a small technicality, but a technicality just the same.
Well, this experiment paid off for me and was interesting (it always is) to work through. After building several different versions it became clear those KD522 diodes were "important" to the tone and gave the circuit a slightly wild edge while keeping the harmonics and tone intact. They have a slightly wider freq response but with more compression which gives more bottom end while keeping everything tight and clear. This is a VERY nice version and may actually kick my standard Civil War off my top two ?
I managed to buy whatever I could of the leftover transistors and diodes I could through my friend so I could at least make a hand full of these. While I really believe the transistors don't make much (if any) difference to the tone and harmonics the diodes are definitely part of the sound and the jury is out as to weather the series caps change anything significantly, I'll keep them in as that how the originals were.
I have enough NOS original transistors to make "about" 40 of these in completely original form but managed to get A LOT of NOS diodes so depending on demand I may make some with replacement transistors but still with the original NOS diodes and series caps after these initial batches have gone ?
This was another fun project that resulted in something special. Developing pedals like this is something I find quite therapeutic when I can find the time. Keeping this place going has become something MUCH more than I ever intended it to be but I'm certainly not complaining. It's a great way to spend some time.
The Mk II is HERE.