Chuck D. Bones
Circuit Wizard
I built the Aldrin Fuzz as a Skreddy Screw Driver Mini Deluxe.
If you study the schematics, you'll see that the Skreddy Lunar Module (aka Aldrin) and Screw Driver are basically the same circuit, with a few component value tweaks. The most significant difference is the transistors. Lunar Module is all silicon: Q1-Q3 = BC109C. Screw Driver is a hybrid: Q1 = BS170 (MOSFET), Q2 = BC109C (Si), Q3 = AC127 (Ge). That big aluminum block is the AC127's heatsink. It doesn't need a heatsink in this pedal, that's just how it came. The Screw Driver has a 9.1V zener from G to S on the MOSFET for ESD protection. I installed that on the bottom of the board.
This is one great sounding Fuzz, but it's more than that. Dial the Fuzz and Range down and it can be a clean boost or a treble booster.
The film caps I used are a little chubby, so things got a bit crowded at the end of the board nearest the switch.
The LED location on the last page of the Build Doc does not line up with the LED pads on the board. I moved the LED hole up 1.7". I also moved the IN and OUT jacks a little closer together so they would clear bosses in the chassis corners.
I haven't got the front panel artwork thing together yet; I'm learning how from people on this forum.
- Chuck
If you study the schematics, you'll see that the Skreddy Lunar Module (aka Aldrin) and Screw Driver are basically the same circuit, with a few component value tweaks. The most significant difference is the transistors. Lunar Module is all silicon: Q1-Q3 = BC109C. Screw Driver is a hybrid: Q1 = BS170 (MOSFET), Q2 = BC109C (Si), Q3 = AC127 (Ge). That big aluminum block is the AC127's heatsink. It doesn't need a heatsink in this pedal, that's just how it came. The Screw Driver has a 9.1V zener from G to S on the MOSFET for ESD protection. I installed that on the bottom of the board.
This is one great sounding Fuzz, but it's more than that. Dial the Fuzz and Range down and it can be a clean boost or a treble booster.
The film caps I used are a little chubby, so things got a bit crowded at the end of the board nearest the switch.
The LED location on the last page of the Build Doc does not line up with the LED pads on the board. I moved the LED hole up 1.7". I also moved the IN and OUT jacks a little closer together so they would clear bosses in the chassis corners.
I haven't got the front panel artwork thing together yet; I'm learning how from people on this forum.
- Chuck
