Intro: Passive Overdrive Pedal - That's Right, NO Batteries!
This is my first instructable, so please be kind. I found an instructable a while ago that spoke of a passive overdrive - black ice. This can be bought for extortionate prices, but somebody found out that it was only really worth about £1.20 (that's about $2!) The company were making a 1400% profit!
It has got better, however, with a slightly more complex circuit and various ways to wire it. I don't know how they do it (I don't know a great deal about electronics), but I have found a way to make it into a pedal with true bypass. Yes, TRUE BYPASS! (the ones on the black ice website don't have true bypass)
I wired the original black ice, but you can use JoeBeau's rectifier with a different way of wiring it. I have got a theory on how to wire it like this, but I haven't tried it, so please correct me in the comments if I'm wrong.
I got help from:
Let's get started!
Step 1: Tools and Materials
- soldering iron and solder
- wire cutters, pliers etc - whatever you can use to help (e.g, I used a screwdriver to bend the leads and from the diodes around lugs)
- marker pen (for decoration!)
- project box
- DPDT switch
- 250k pot (I'm not sure whether I used linear or audio taper and I can't be bothered to check - it doesn't really matter)
- 2 x 1/4 inch output jacks
- 2 or 4 x 1N5818 Schottky diodes (I forgot to thank this guy for which diode to use - I wasn't going to keep buying diodes until I found a good one!)
- some wire
Step 2: The "Schematic"
There is a proper schematic diagram and a simpler one that I can get my head around. Use whichever suits you.
For the wire, I used white for hot wires and black for ground. I think this is the convention.
Diagram shows pot from the side opposite the turning part.
Normally circuit diagrams only use one colour for the wire, but I thought it would be helpful to put one colour for hot and one for ground.
The last one is only a theory on how to wire the full wave rectifier onto it - it may not work. If someone finds it doesn't, please put it in the comments. Check them before you try it.
Step 3: Prepare Project Box
Drill the holes you need
Step 4: Prepare Diodes
You can use JoeBeau's help for this, but here are my pictures and diagrams.
Step 5: Prepare Potentiometer
If you want the gain to increase as you turn it clockwise (like a normal person), attach the diodes to lug 3.
Step 6: Prepare DPDT Switch
I found this incredibly difficult because the lugs were very small on mine. But I digress. The middle lugs are for the hot wires to the jacks. The bottom are connected to each other. The top two are also connected to each other, but the left one is also to be connected to lug 2 on the pot.
You can flip the top and bottom (i.e. the pot can go on the bottom two and the wire on the top), but the middle ones must be the same.
Step 7: Attach Jacks
Attach the jacks to the switch. I use the left one for input and the right for output to be safe, but I don't think it matters.
Solder a ground lead to connect the jacks to each other.
This picture above will help you determine which lead goes where if you are a complete novice to this, like I was a while ago. The tip connection is hot, the sleeve is ground. The tip lug is usually the furthest from the tip, confusingly.
Step 8: Add Potentiometer
Put the potentiometer to one of the top lugs. This is what I got at the end. It looks messy now, but it cleans up a little when in the box.
Step 9: Put in Box
Step 10: Decorate!
This is what the marker is for.
Step 11: Done
Feel free to experiment with different diodes etc and if you find a wiring that's better or a diode with a particular sound , please describe it or explain it in the comments for future viewers of this to benefit.
I heard that you can get a distortion by only using only one diode and that you can smooth out the tone with a capacitor. You can also use germanium diodes like the ones used in pedals like Electro-Harmonix Big Muff. You might find that mixing different types of diodes produces a different sound. I found that my overdrive was more like a fuzz, but this could be different with different diodes and wiring methods. Feel free to experiment and add results in the comments.
I tried it with LEDs, but it didn't work for me - it might be because my pickups are too weak.