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Boosting gain in an effects pedal

[Author: Yun]
This is a VERY handy Mod that can improve any ordinary OD, Distortion, or fuzz. What it does is Create “assymmetrical clipping” using diodes.

Thoughts on diodes:

There are many Varieties of diodes. The 2 Main diode types are germanium, and Silicoln.

Germanium is what your most likely going to find in Vintage circuits. Such as the the First editions of the Big-Muff Pi, and the Univox Super-Fuzz. Germanium is not capable of of the “drive” we’d hope to get from this mod. So let’s move on….

Silicoln Diodes are what we’re after. 1N914 to be exact. Silicoln diodes are found mostly in newer circuits. Like the Boss DS-1, Big-Muff Pi re-issues, etc.

So, now that you have a little more knowledge on Diodes, let’s get to work, shall we?……

Tools needed:

  • De-soldering braid
  • Soldering iron
  • a couple 1N914 diodes
  • solder
  • Needle nose plyers
  • Needle nose wire cutters

Step 1) First, gain access to the PCB (circuit board). Make sure that your battery is unplugged from the battery snap.

Step 2) Locate the Diode clipping stage(s) . Once you’ve done that, Look for the solder trace belonging one side of the diode on the other side of the PCB.

Step 3) Using your de-soldering brain; lay the braid on the solder connection you wish to unsolder. Take your soldering iron, and Head the braid while laying on top of the solder connection. keep the soldering on the braid with a tiny bit of pressure for about 3-5 seconds. The solder should suck up into the braid.

step 4) Flip the board back over. Using your needle nose plyers pull the side of the Lead of the Diode that you’ve unsoldered. Raise the diode to where it’s sticking up.

Step 5) Use this schematic:


This particular schematic Shows 2 Diodes on one side, i like to use 3-4. remember; the more diodes you use, the more gain it will put off.

Stick one of the diode’s leads through the solder hole. Flip the PCB back over. Resolder the connection of the new diode. Clip the excess Lead with your wire cutters.

Now; with the Other lead of the diode- take a second diode, and twist it’s leads between the new diode, and old diode. Put a glob of solder on your soldering iron. Solder the twists together. Cut off the excess leads with your wire cutters.

Step 6) Using an amp (i prefer a practice amp for testing) plug in your battery to your pedal. Then plug up your distortion. Make sure everything works right, and make sure your satisfied.

Step 7) Once your satisfied, re-assemble your pedal. Once assembled make sure everything works a final time.

Step 8) Enjoy, and jam….

[Note: many of the below links are long dead. But kept in place for historical reference.]


Extra info:

Begginner Effects sites for DIYers and modders:

[Article by: Yun-Jinn Pequesso’; 3/1/04]