Push Me Pull YouI'm starting to have a large octave fuzz collection these days. I didn't need another octave fuzz, but what drew me to this one was how clean it could get. I decided to mod the Q3 transistor by cutting the collector or emitter in order to kill the octave effect, making the pedal a stand alone fuzz with the stomp of a switch.
There seems to be a debate over which matches of transistors works the best for a strong octave effect. I found the following to work fairly well: Q1 2n5088 Q2 2n2222 Q3 (switchable 2n5087 / Ac125) I also changed out the 500K resistors for 470K resistors. I think it help the octave a little.
Octave Fuzz (Tim Escobedo's Push Me Pull You)
Harmonic JerkulatorThis one is not subtle nor pretty in anyway. What drew me to this one was the tone of Steve Albini. His Big Black albums have the craziest tones, almost metallic and harsh. His rig is hard to reproduce, especially considering his main dirt box is the extremely rare Harmonic Percolator. There is even much debate about reproducing the original. The values are questionable. I think Tim did a pretty good job with this one. We can get in the ballpark for that tone, but some more tinkering might be in store.
Lets look at the original schematic:
I also added a switch to change the NPN transistor between a MPSA18 and a 2n3904. There is a slight difference between the two. Not much, but the MPSA18 has less feedback overall.
The last mod I did was to change the 1K resistor from the gain pot to a 10K. The drop off of gain was a little less. The 1K basically made the gain go away completely, the 10K made it more useful.
Harmonic Percolator variant (Tim Escobedo's Harmonic Jerkulator)
|Some Big Black graphics I hope to add to the pedal|
Utility BoostThis is one of the easiest boosts to build. Lots of volume on this one. The variation really seems to rely on the type of transistor or jfet used. So I added a switch to give me both a jfet and transistor. The J201 is super clean. It only starts to slightly hair up at max. The 2n3904 transistor has much more gain and fuzz to it. However there is a sweet spot on it and anything above that is not so musical or pleasant. I think i might switch out the transistor. Maybe I can get a hold of a NPN germanium soon. Here's the original schematic.
Boost Pedal Clean/Dirty (Tim Escobedo's Utility Boost)