Project: Colorsound Overdriver / Power Boost / CSOD

I have just completed my first full project to share here on JustOneMoreBuild, a Colorsound Overdriver / Power Boost / CSOD. I will be sharing the complete project files, minus the enclosure artwork, so you can build your own. It came together quickly– I started working on it on Christmas Eve, and finished it tonight. There was no debugging, and just a couple of resistor swaps to adjust the bias. It sounds great.

First, this post is useless without pictures:

And here are the project files: Colorsound Overdriver – JustOneMoreBuild. It contains ExpressPCB sch and pcb files, and a PDF toner transfer image.

As you can see, this project uses Alpha board-mounted pots, box caps, and 0.4″ spaced resistors. The layout is spaced 25% larger larger than perfrboard– all components are at least 0.125″ on center from any other component’s pads. There are no jumpers.

On my build, I used a scratch-n-dent enclosure that had already been powder coated green. I sanded it with a random orbital sander to level the top (it had a bubble), and to cut the gloss. I went back and scuffed it further by hand with lower grit sandpaper.

The top is a piece of copper clad from Tayda. I found a design online, modified it slightly to meet my uses, and added a border and some labels. Once it was etched and trimmed, I applied liver of sulfur, which creates a patina. It was my first time using it, and it was very cool.

I applied the liver of sulfur, which can be found in the silver jewelry wire section at Michael’s, at full strength using a q-tip. It instantly blackened the copper. I let it sit for a minute or two, and then rinsed it off with water. Over the next 10 minutes, the copper peeled and flaked– you could actually see it– revealing a pretty cool finish. It looks different depending on the light. Sometimes it looks blue, silver, gold, red, or a whole rainbow of color. It is pretty cool.

My labels came out a bit thin, so I will be sure to use a bolder font next time I use this method. I am pleased with the overall finish.

For the LED, I decided to use the circuit board top as the indicator. I mounted three superbright LEDs on a little piece of vero, and attached it to the switch with double-sided tape. The LEDs draw about 5mA each, and do not add any pop to the switching. I drilled and filed the enclosure under the word Overdriver, so the LEDs light it up when the pedal is engaged. As you can see, it came out great.

You might be wondering how it sounds. It sounds fantastic. It can go from a nice, transparent boost with a lot of volume, all the way to a medium fuzz with a good deal of gain. The tonestack is pretty flexible, and allows you to dial in a broad range of useful settings. I had built one of these before, so I knew what to expect, and I was not disappointed.

I did make a few minor changes to the circuit. I didn’t have any 6.8uF capacitors, so I used a 4.7uF. I used a reverse audio taper potentiometer for the gain knob, and I highly recommend this. Otherwise, the fuzz is all piled up in the tiniest little portion of the potentiometer’s rotation. I used random BC550 transistors, and I biased Q2 and Q3 as close to 5v as I could get (4.8 and 5.1, if I recall correctly). Other than that, it is stock.

If you have never built a Colorsound Overdriver, I suggest you give it a try. I think you will like it.

More to come!

2 thoughts on “Project: Colorsound Overdriver / Power Boost / CSOD

  1. I’ve been looking for a good circuit trace for the Powerboost for a long time. I downlade your zip file for this one and it looks very nice. When i unzipped it, the other two files showed up as.print and .pcb; neither of which I am able to open on my computer. Are you able to upload those as pdf’s? That would be super awesome.

    Thanks,John

  2. Hi John,

    The files open with ExpressPCB and ExpressSCH, both part of one free software package. It will allow you to view and edit the schematic and the layout.

    https://www.expresspcb.com/free-cad-software/

    Freestompboxes.org has a big topic on this with the three variations (if I recall correctly) of the schematic, and lots of discussion. I haven’t been there in a few years, but I am sure it is still there.

    Mike

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