Found the schematic for this over in the Aron Nelson Gallery. It's designed by Scott Frein. Uses a simple JFET buffer to help push the transistor-based drive section. Here's his description:
A pretty simple overdireve. The buffer on the front really brings it to life. Good AC/DC,ZZ Top crunch from this. Hit it with a booster and go from JCM 800 to Fuzz.
Hey brother,
ReplyDeleteThis is Raf from Brazil again.
Well, unfortunatelly I can't find the J201 and the 2N5089 for this project, and the 2N5457 for the Fulltone Fatboost anywhere around here.
I could find the 2N5088, 2N5087 and the 2N5064, though. Could I replace them with those?
Thanks again for your help,
Raf.
No, Q1 in this effect needs to be a JFET. Same for both transistors in the Fulltone. If you're limited to those 2N series, I would say try some fuzz effects. You could build the Jordan Bosstone with a 2N5088 for Q1 and a 5087 for Q2. The EHX Axis Fuzz/Guild Foxey Lady would also be a good candidate (use 2N5088s). You could also try the Greer Amps Green Giant, Earthquaker Devices Speaker Cranker, or the Lovepedal COT50. But they're very closely related to the Lovepedal Woodrow and would give you a pretty similar sound.
DeleteHi, maybe there is an error in the scheme, can you show the original scheme?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThe layout is missing a 100k resistor from Q2 base to v+. Adding an extra row up top would give enough room to fit the resistor and make the connection.
ReplyDeleteI just made this one with some small layout changes: I put the Q2 base to Voice 3 100nF cap directly above Q2 (column J) and then installed the missing Q2 base to 9v 100k biasing resistor where the cap originally was in column F. Q2 was mis-biased, so I experimented and found that increasing the 100k resistor to 180k or 220k worked well.
ReplyDeleteWith the Voice pot panned towards the 10nF, you get a light OD clear enough to use with barre chords. Turning the knob clockwise gets you towards a fuller, mid-gain OD. The mid-gain sound is good, but I think the circuit shines at low gain.
I also tried different clipping configurations and did not notice much difference between two Si diodes and the stock Si/Ge pair. With no diodes, you get a dirty boost with better dynamics, but the distortion on low notes can sound a little crackle-y. LEDs clippers are somewhere in the middle, as you might guess.