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.

Friday, August 18, 2017

Frantone The Sweet

Laying out Big Muff variations never gets old for me. This one uses germanium transistors in the two clipping stages (and predates the EQD Hoof which also uses germanium transistors) along with schottky diodes (1N6263s). Q4 is a FS25444, but the usual BMP transistor suspects will work as well (2N5088, MPSA18, BC549C, etc). Other than component values, the biggest difference between this and a typical Muff is the placement of the tone section. On a typical BMP the tone section is immediately following the 2nd clipping stage, followed by a gain recovery stage. Here, the gain recovery stage follows the 2nd clipping stage, pushing the tone stack. Schematic can be found over on FSB.

The bass version, the Bassweet, can also be built on this board with just a few value changes. The Gain and Tone pots are changed to A10k, and the rest of the value changes are illustrated below:


  1. Is there a cheaper substitute for Q2 and 3? NTE103As are incredibly expensive for me

    1. AC127s are equivalent to the NTE103. Highly suggest using sockets and trying out different germanium transistors if you can. When I've used germaniums for Q2-3 in Big Muff style circuits like this anything with an HFE of 200-300 has worked well.

  2. Finished my Bassweet build finally today. Used Sanyo SD72 for Q2-Q3. Seems to work but it is too late to be ripping holes in the walls with my bass so i haven't spent much time with it. I don't remember what hfe range they were in when i tested them sorry. Not sure that qualifies as "Verified".

  3. fwiw the volume control on my bassweet doesn't seem to do much, and the sound is a bit on the glitchy and gated side. i will fiddle around with it and see what i can figure out.

  4. I forgot to use the different pots on my Bassweet build, but i also think that my 2sd72 pair, though low leakage, don't have a high enough hfe at 80ish. Also tired of using mill-max pin sockets meant for IC pins as transistor sockets so i ordered some real TO-5 sockets.

    I'll order a few of the "Hot NPN" germanium devices from smallbear and report back when it's all rebuilt.