February 15, 2006:
The Boss Distortion is one of the oldest distortion units, dating back to the late 1970’s. This is the second unit I’ve owned. The first one was traded off before I started modding pedals. Good thing they have a good street price ($40 at the time of this writing). There are a few version differences throughout the years. The main change, around 1994, was that the Toshiba TA7136AP opamp was replaced with the Mitsubishi M5223AL.

There are many different mods out there for the DS-1. The two that I have decided to take on are by Robert Keeley and by Bob Melanson (Melanhead in the DIY world). There are some aspects of each that I like so rather than do one over the other, I combined them a little. The dual 3mm LED’s as clippers rather than one was my experiment. Most mods call for one but I like the sound of two for even more crunch, much like the old black Marshall Guv’nor.

• C1, C10 – change to 0.047uf
• C2, C8, C14 – change to 1uf
• C3 – change to 0.068uF
• C5, C12, C13 – change to 0.1uf
• C9 – 0.47uf
• C11 – 0.033uf
• D4, D5 – change to Red 3mm LED
• R13 – change to 2.2k
• R14 – change to 1.5k
• R16 – change to 4.7k
• R39 – change to 22k

All capacitors are Panasonic metal film although silver mica or poly film would be fine too. Some of the caps are left the same value and just replaced with better quality caps (who knows how much difference it makes but what the heck …).

All resistor changes are 1% metal film but carbon film can be used as well and close-enough values are acceptable (i.e. 2.2k vs. 2.4k; 22k vs. 20k). Since my parts stock is missing some metal film resistors, I opted to use what I had and went with carbon film with little to no noise increase.

Play with the value of R13 as this controls the amount of distortion. Lowering this value increases the distortion. For D4 and D5, the combinations of diodes and LED’s that can be done are endless. Try series LED’s, series LED’s and diodes, series diodes. Let your ears decide.

Thanks to Robert Keeley and Bob Melanson for their mods.

August 29, 2006:
Changed R13 back to stock value of 4.7k. Changed D4 and D5 to 1N4001 and 1N4148 respectively.

May 14, 2007 (updated November 2, 2007):
Changed R14 back to stock value of 2.2k. Changed R39 back to stock value of 4.7k. Put back in stock caps that were replaced with same value. Reverted some other caps back to their stock value. Adjusted parts change list (below) to reflect actual part and value changes.

This is my minimal mod that really changes the sound of the pedal enough that it can be a standalone distortion through a clean channel with a good full sound.

• C5 – change to 0.1uf
• C11 – change to 0.047uf
• C13 – change to 0.1uf
• D4 – change to 1N4001
• R16 – change to 4.7k

January 23, 2008:
Here is another low parts count mod that I call, Minimal Mod Part II. C5, C11 and C13 are back to their stock values, 0.47uf, 0.022uf and 0.047uf respectively. R14 was raised to increase the lows. R16 was lowered to increase the mids.

• D4 – change to 1N4001
• R14 – change to 4.7k
• R16 – change to 2.2k

These three changes make the DS-1 in to a great sounding distortion. It sounds excellent with both single-coils and humbuckers.

January 25, 2008:
First, I need thank Brian Wampler of indyguitarist.com for this mod. He has a featured article in the February 2008 edition of Premier Guitar magazine and he shares some great info about modding the DS-1. By doing one of those mods, other than all the diode changes, it sounds fantastic. So, starting off with a stock DS-1, make the following changes.

• C2 – change to 1uf
• C3 – change to 0.033uf
• C5 – change to 1uf
• C9 – change to 1uf
• D4 – change to 1N4001
• R16 – change to 2.2k
• R17 – change to 15k

Read the full article on premierguitar.com here: Boss DS-1 Mods