The Marshall JCM DS1 Mod

After having the DS1 with the Wapler Modern Distortion mod for a few weeks, I wanted to hear how the classic Marshall JCM Tones Mod would sound like. I liked the Modern Mod, but wanted to experiment, and the Modern Mod just didn’t cut if for me in lead work.

First things first I put the pedal back to stock and tested it to make sure everything was in proper working order, then I did the Wampler Marshal JCM mod, the mod includes the following changed;

-D4 = 1N4148 Connected in Series to another 1N4148

-D5 = 1N4001 Connected in Series to another 1N4001

-R13 = 1k

-R17 = 15k

-C8 = 1uF

-C9 = 1uF

-C5 = 1uF

-C2 = 1uF

-C3 = .033uF

The JCM mod the bass response of the pedal (C-3) is drastically reduced so that no bass frequencies can be inserted before the clipping stage. Mr Wampler says that having bass before clipping makes for a more ‘Fuzzy’ type distortion and gives you a more splatty sound on the decay of notes. He’s right, with the JCM mod that is what higher cap values do to the sound and its ok but gets a little annoying with higher volumes.

Completing the Marshal JCM mod proved the pedal to have a more vintage / treble sound to it and makes for kind of ringmaster treble booster into a tube amp hi pitched distortion sound. It would work great with a bass heavy amp but my amp is a little on the treble side so it sounded a bit thin and with the distortion all the way up palm muting chug’s just didn’t have much definition.

Still I kept the mod for a while to try to work with it because the overall tone of it sounds good. Mr Wampler also advised to use an equalizer pedal after the distortion unit to get more clean bass from it, however it does exactly that. You get a clean bass response & a dirty hi end response that doesn’t sit well with me. Therefore, I ended up finding a good compromise by using an AMZ mini boost pedal in front of the DS1. With the Mini Boost pedal, it fattens up your tone in a big way so you get just enough clean bass to make the distortion pedal sound a bit fuller. Therefore, setting the Mini Boost pedal to unity gain and backing off the DS1’s tone knob a bit gave me a nice distorted tone similar to pushed amp.

The noise floor of the pedal came down a lot with this mod, however I believe it’s because of having less gain on the distortion control.

In the end it’s a different sounding distortion from the original tone, more realistic but for my tastes lacks in bass a bit much for my rig. Combining a little bass in front of the DS1 proved to make it sound fuller for my liking and that’s the way I kept if for about a year.