Send in the Clones: Fulltone Fulldrive II Mod for a Boss SD-1 Clone

Modding a Boss SD-1 clone was a pleasure. So far, it’s the second pedal I’ve souped up. This time, I went for a full-scale mod; I did everything as instructed. Now I have a pedal that’s supposed to mimick a Fulltone Fulldrive II and I am very pleased with the results. Next time around, I’m going to buy myself a real Boss Super Overdrive and mod it exactly the same way. This project was completed in half a day. It was fun, but not without some lessons learned.

1. Make sure to ask the seller if his pedal had been modded and cross your fingers that the truth had been told.

If not, bring the necessary tools so you can examine the insides of the pedal. I was pleasantly surprised to hear the clone’s sound before I modded the stompbox. It sounded good, very much unlike the sound of a Boss SD-1 that I remember. True enough, when I went to check the circuit board, I found out that one diode was changed to an LED and a capacitor was missing. There was also an IC socket, which had a JRC 4558 sitting on it; however, I’m not sure if this clone was  really built that way, but the soldering work on the socket looked different from the rest. After painstakingly checking for the original component values, I also found out that a resistor was changed. In addition, one of the legs of a transistor had solder that seemed to float above the circuit board. Closer inspection showed that the conductive material (the one that is left after the board is etched) where the solder was made had been partially gone. I had to remove the solder and resolder it to make sure that there was good contact with whatever remained of the material.

2. Remove the solder completely and make sure that the electronic component can be removed without yanking it out by force.

I ‘tore’ the circuit board’s copper trace where a capacitor sits. I was in a rush to insert one huge film capacitor that I pulled out the original capacitor even if it had still been partially soldered to the board. So I took out a sharp blade and scratched out the top to expose the foil. The magnifying glass helped me confirm that the solder would stick, so I went for it. It was a success. Before that, there was no sound at all. Yes, it is really important that you do a sound check after each component is replaced or you’ll have a hard time figuring out where you went wrong.

3. Not all distortions can sound like an overdrive without the proper modification, especially those with dual-stage distortion.

When you back off the gain on some distortion boxes, it will not necessarily sound like an overdrive pedal. I proved that when I actually tried to compare the sound of both.

So much about lessons learned. Right now, I’m still awed by the sound my pedal makes. I play through a solid state amp that has analog modeling features, so I guess that it emulates most of the characteristics of a tube amp. Once I get hold of a tube amp, I will make that long-awaited comparison just to prove myself right.

Well, I’ve never actually tried a Fulltone Fulldrive II, but if my pedal really mimicks the said pedal, then I guess I did the right thing. It’s really hard to tell just by listening to the Fulltone clips because they sound like they were set too clean for my taste; however, they do sound really good because the guitar sound isn’t altered much. Unlike my Boston DS-100 with a really low distortion setting, my SD-1 clone (which can go by the names Denio, Dixon, Maxtone, Maxx, Rockson, Century, Wilton, and Lazer — thank goodness it’s just a sticker that easily peels off) sounds clean when the drive is set to 0 and sounds pretty much like an overdriven tube amp with the drive up. The mod has also given the pedal more bass, which sounds fuller to me. Regarding the distortion, there is this kind of silky smoothness that I hear. 

I haven’t done the other mods, but I guess that Brian Wampler’s mod is the mod of all mods for the Boss SD-1. Since many Fulltone products came about via reverse engineering of popular pedals (yes, that’s what I’ve read), then I believe the mod could somehow be an accurate emulation of the Fulldrive II. I guess I now have the confidence to mod a real Boss SD-1.