The projects list

I have quite a list of little electronics projects to finish:

1. Build a new Champ Amp chassis: I have a board, components, transformers, pots, wire, etc. 
2. Build a Deluxe Amp clone
3. Finish "Old Ironsides"  (test transformers)
4. Repackage NPN Fuzz, and test with different components
5. Build GGG Shin-Ei Companion Fuzz kit
6. Build GGG Mini Mixer Kit
7. Build a few Craig Anderton EPFM projects

Boss HM-2 Repair - Part 3 (final)

So I got the HM-2 fixed, but it wasn't without its problems.

The pins on the DS-2 replacement pot are a little too short to get all the way through the board with ease. In addition, the replacement pot doesn't have board mounting tabs on the LH and RH sides, so the mechanical connection isn't as good. 

So first I unsoldered the old pot and saved it. 

Next I bent the pins carefully on the new with some pliers. Then I soldered the pot in at a shallow, slight angle, so that the pins could make a strong connection on the other side of the board. Finally I went to bend the pot flush with the board after it was soldered and I heard a crack: apparently the phenolic mounting wafer on which the pot is mounted cracked. I checked the pot values to make sure it was still working, and it was still in spec. I also spun the knob, and felt a tiny "tick", like a detent, in the action, about 1/2 way. 

Closed it back up, took it to the guitar lab and plugged it in, all good! I felt a little like the new pot didn't have the same range as the original; but then again I haven't use the paddle in many years so I can be sure. It seem like between 7 o'clock (zero distortion) and 9 o'clock, the sound goes from a heavy over drive to a mean growl. From 9 o'clock to noon, it gets funnier and deeper. From 12 o'clock to 5 o'clock though I can't tell much difference, I don't seem to hear much of a difference in sound. That may be because I was testing it out on my DG stop and it was very oversaturated.

The replacement knob is slightly brighter orange than the original 3 knobs, but that may change with time & grime.

Happy to have it all back together and working. 

Screaming Bird fix

I got my EH Screaming Bird pedal fixed today. Took some mucking around, developing a wiring diagram, testing... Jack Ormans LPB-1 schematic was the closest to the actual values in my Screaming Bird; the other common schematics used different transistors with  different values. 

Found some wiring photos of other LPB1 and Screaming Bird online and was able to deduce and test wiring through trial and error. 

Here was it in the testing stage, wiring here is wrong, but pretty close:

I had to replace a missing DPDT switch, which I found at Radio Shack a few weeks ago...nice that thy still carry parts!

Here was the final wiring diagram that worked, so I drew it up:

I think it's interesting that +9V runs to the Jack sleeve (traditionally ground!). The values in the diagram above are the actual ones I observed/measured. As in the other schematics I've seen, you could easily substitute the two caps for .002uF, or other more convenient values. 

Looks nice buttoned up, and sounds nice too!