This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.
Here's an other heavy one. This one was designed by Martin (aka soulsonic) and is basically 3 transistor stages and a tone stack into a JFET gain recovery stage. The toggle switch selects between distortion and fuzz.
The tone in Distortion mode is a big heavy, "Doom-y" sort of thing with alot of sustain. In Fuzz mode, it's a fart-y ripping sawtooth fuzz that's good for single-note lines and possibly bass, but it can do chords without totally falling apart. The Contour control adjusts from a dark, low-mid-heavy tone when counterclockwise, to a scooped tone when clockwise. Around 12 o'clock it has a bit of a mid-peak.
Schematic and demo can be found here. I added a trimmer to bias Q4 (J201 or 2N5457 would be good subs). Should fit nicely in a 1590B.
Here's another design by Martin from Soul Sonic FX. Here's what he had to say about it over on FreeStompboxes:
It's a cool little hybrid combo of an opamp driving a MOSFET. It has a great range of drive, from light and crunchy to thick and heavy. At it's highest settings, some people might consider it a distortion, I guess it just depends on how hot your pickups are. You can see some fun tricks used in this circuit; subtle things that give it the special charm it has.
Here's a cool overdrive circuit designed by Martin from SoulSonic FX. It's said to be a "Klon Killer," so if you've been disappointed by that circuit, give this one a go. Signal goes through a buffer then is split between clean out put and the rest of the effect. So not a true-bypass effect, but having a buffer in your signal chain won't kill you. And the buffer on this thing is really top notch. For switching use one side of a DPDT for the effect, and the other for the LED indicator. For more info and the schematic, check out the thread on FSB.
Here's a well designed buffer by Martin from SoulSonic FX. Use it as a stand alone buffer or as an output buffer in another pedal. Should fit easily in a 1590a enclosure.
The Folk Driver is a low-medium gain overdrive developed by SoulSonic FX after being challenged by Björn Juhl (of BJFE) to create a DIY project inspired by sound of the BJFE Honey Bee. Here's what Martin (soulsonic) had to say about it after designing the circuit back in '09: My goal was to keep the design as simple as possible, but still try to fit in some tricks. This uses both positive and negative feedback to get its sound. R8 [100k resistor between emitters] is something I learned from the big old red RCA book – it’s positive feedback to boost the gain of the first stage; it was suggested as an alternative to using cathode bypass capacitor in a tube stage, well, it works just as well with a transistor. The combination of R9+C4 [100k and 470p in series from Q1 emitter to Q2 collector] is negative feedback to reduce the high frequency gain and give the signature smooth sound. It also promotes stability in the circuit. I settled on the clipping diode combination after trying several different kinds, and the 1N4001+1N4148 combo had the best sound for this thing and reminded me most of the HB.
The Timbre control adjusts both the low-frequencies and the amount of drive. At the 12 o’clock position is the minimum drive amount. At one extreme it’s max gain with lows emphasized, and the other is max gain with the lows cut. It’s sort of like having the HB’s Gain and Nature controls on one knob.
Should fit in a 1590a just fine. Here's a demo:
