Help revive my old Sola Sound Auto Wah

[mwynwood]

I don't know too much about this pedal, it was given to me years ago - and I foolishly took it apart so that I could use the enclosure for something else!
Years ago I spray painted the enclosure, but I can make out through my bad paint job that it said "Sola Sound, London England" and the knob is labeled "Intensity" I can't see what the switch was labeled.
I think it was an Auto-Wah. It has one knob, one toggle switch and a footswitch. No LED.

Now that I know a tiny bit more about electronics and pedals, I'd like to get it going again.
If anyone could help me identify how I might hook up the pedal back to it's power, switchs, and inputs and output I'd be very grateful.
I have numbered the points where wires were attached 1-8.
Thanks for your help! 

[mwynwood]

It would be easy enough to randomly attach the knob, switch and power until it works...
But what I am really worried about is can I damage it if I applied 9v power to the wrong point??

[R.G.]

can I damage it if I applied 9v power to the wrong point??

Yes.

Can you retake photos top and bottom from as nearly straight down on the center of the PCB as possible, and fill the frame? That would make it possible to trace the circuit out and tell you where +9, Ground, input, output, etc. connect.

[mwynwood]

Thanks for the reply R.G.
I'll post some more photos tonight.

[mwynwood]

I found some gut shots and a schem!
http://www.effectsdatabase.com/model/colorsound/chuckawah
Woohoo!

I'll let you know how I go... thanks! 

[Mark Hammer]

Note that the quad "op-amp" used is a MC3401p which is a Norton quad op-amp.  Different than a 324/TL074 or even a 4136, both in terms of pinout AND performance.  Equivalent to an LM3900.

[R.G.]

I found some gut shots and a schem!
http://www.effectsdatabase.com/model/colorsound/chuckawah
Woohoo!

Hmmm. All four of the links to schematics on that page seem dead. Is it just me?

[pinkjimiphoton]

rg, i believe i have the schems in my archive if someone needs them, i'll go digging..

[reverberation66]

yea, schematics dead for me as well, I really wanna see what this circuit looks like.

[mwynwood]

Here they are:

http://dl.dropbox.com/u/22593339/colorsound-chuck-a-wah-fet-schematic.pdf

http://dl.dropbox.com/u/22593339/colorsound-chuck-a-wah-led-schematic.pdf

[pinkjimiphoton]

here ya go

[R.G.]

Thanks jimi.

The circuit board is obviously the JFET version, not the LED/opto version, so a little checking should verify the wiring shown in the schemo.

[pinkjimiphoton]

if this thing sounds anywhere near as cool as the diphonizer, you're in for a treat...great sounding effects, i love using volume swells with dynamics...crazy sounds.

[mwynwood]

It's revived!
According to the Effects Database, the Chuck-a-Wah was made from 1975 to 1977.
Here are a few photos for anyone interested...


Removing the mat black spray paint was tricky.
I tried Nail Polish Remover, but someone suggester Petrol, and that seemed to work the best.
I had to be very delicate so as to not remove the blue paint.



Here is the box fully assembled. It's definitely in a "used" condition!



Here is the re-assembled and working gut shot.

[pinkjimiphoton]

oh, bugger.

now i wanna build one.

can ya post some clips, marcus?

[mwynwood]

Here is a quick sound clip:
http://soundcloud.com/mwynwood/testing-my-chuck-a-wah

[deadastronaut]

cool nice to see an old pedal revived...

[mwynwood]

I'm not sure how useful it will be, but it's kinda cool and I'm glad I've got it going again 

[DiscoFreq]

Wow, really cool to see how you managed to remove a layer of paint and still keep the old paint!

I have one of these too, but it's the version without that little switch.

Hmmm. All four of the links to schematics on that page seem dead. Is it just me?

Yes, the site with the schematics I linked to is down. I should host more schematics on FXDB, but I know a lot of people don't want their schematics on other sites. People who have a good collection of original or self-made schematics (for out of production pedals) can always let me know if I can use those, because it's a nice extra for the site (and I promise I do everything I can to keep it online ). I'm thinking about a better structure for the documentation (files + database structure, easier way to add them,...) so I can add my collection of old ads and other documentation as well.

[mwynwood]

Thanks Bart - the info on your site helped me heaps