freestompboxes.org

I have one those but it's a bit diferent.
I'll post some pics soon.

rs

I'm just digging in on saving one of these. . .a little help from someone familiar w/ the fuzz circuit would be GREATLY appreciated. I'll update this thread later w/ my progress.

I'd seen what D. Main did w/ one & when I saw one up for grabs, I went against my better judgment & hit it. For those not familiar w/ the D*A*M custom piece, check > > >HERE< < <

Pix of mine here:


Mine is a bit of a basket case, and pretty badly rusted, but it actually works & the pot(s) are even quiet. The little trimmer on the fuzz board is soldered in place & there is evidence of some ham fisted repairs on the traces around it. Looks like one of the spacers went missing the board shorted @ the cap which has been replaced w/ a jumper (I think). Also, there are 3 new holes in the pedal, so I plan on adding 1) a Boss style DC jack, 2) an external vol. pot for the fuzz volume & 3) an external gain pot for the fuzz (if possible). On mine there is already a separate stomp for both the fuzz circuit & the wah/vol. This makes the rotary selector unnecessary. I'd like to leave the stomps & pot in place as they seem to function just fine (for now). Can always change 'em up later if the need arises. For now, I'm after a tidy up & getting it 100% functional + the above mentioned mods.

Anyone have a schematic or know what kind of fuzz circuit this is? Any suggestions for other stuff to clean-up while the boards are out?

....what kind of fuzz circuit this is?

A Fuzz Face circuit with slightly different component values (47k instead off 33k, 100 Ohm instead of 330 Ohm, 4µ7 instead of 22µF and input cap 100n instead of 2µ2).

At the place where you have a white jumper wire should be a 100n capacitor.

analogguru

AWESOME INFO - thanks a bunch. Any suggestions for how to add a vol & gain pot? If I'm correct, the trimmer is vol. for the fuzz circuit, but what sets the gain?

Any suggestions for how to add a vol & gain pot? If I'm correct, the trimmer is vol. for the fuzz circuit,.....

Thats right, I can´t read the value but I assume that it could be a 4k7 trimmer in this case.

.... but what sets the gain?

As long as I haven´t seen the track side i can´t tell that for sure. It must be one of the 1k resistors. I assume that it is the 1k resistor between the blue electrolytic and the transistor.

Place the outer lugs of a 1k potentiometer instead of this resistor, remove the + side of the blue electrolytic (should be 4µ7) from the pcb and connect it to the slider of this potentiometer.

If you want more bottom use a higher value for the volume pot (47k) or use a higher value for the missing capacitor (if the trimmer value is 4k7).

analogguru

analogguru wrote: As long as I haven´t seen the track side i can´t tell that for sure.

Well, I'd be happy to fix that!

Well, here is my first attempt to match up the traces to the components on a pcb. The resistor may need to be double checked for verification, but should ok. One resistor in question appears to be grey, red, red, gold, which would be like 2200M ohms, I think. Is that correct?!?! Also, I do not know the pin-outs on the transistors. They look like BC18(3?)(L?). It looks like AG may have a good idea of what the remaining component values are.

Anyway, I had fun doing this and maybe learned something. Anyone wanna try a schemo? I hope someone enjoys this.

That would be an 8.2K.

Grey is 8
Red is 2
the next red is the number of zeroes on the value (2)

that gives you 8200 ohms, or 8.2k

Barcode wrote:That would be an 8.2K.

Grey is 8
Red is 2
the next red is the number of zeroes on the value (2)

that gives you 8200 ohms, or 8.2k

Ok, great! Thanks Barcode.

If anyone is interested, I'll update the drawing when we have all the component values.

Yo

There's a schem out there on a dude named Stellan Lehrberg's site. I'd link it but it keeps saying "this site may harm your computer"
Just like Analogguru said its a fuzz face circuit. 100n input and output caps. 33k=47k, 470r=100r, 8k2 is the same, 100k is the same. There is a 1k between the positive voltage supply and the 47. The emitter bypass cap is 10uf. There's a 22uf from the 1k/47k/100r node to ground. You can tell from your pics the transistors' pinout is E C B.
I love Colorsound stuff.

--Brad

Thanks for the additional info Brad. I'm about to get back from a wonderful 10 day vacation and will need something to cheer me up. May finally find the time to dig in on this. . .

Solidhex wrote:Yo

There's a schem out there on a dude named Stellan Lehrberg's site. I'd link it but it keeps saying "this site may harm your computer"
Just like Analogguru said its a fuzz face circuit. 100n input and output caps. 33k=47k, 470r=100r, 8k2 is the same, 100k is the same. There is a 1k between the positive voltage supply and the 47. The emitter bypass cap is 10uf. There's a 22uf from the 1k/47k/100r node to ground. You can tell from your pics the transistors' pinout is E C B.
I love Colorsound stuff.

--Brad

Hey, thanks Brad! I searched that schem, found it, and got the same warning message. But, your description clears it up perfectly!!!

This circuit sounds really good. Stock it lacks output but still has a really nice thick fuzz to it. Gritty and crunchy but with good low end. I built one up after breadboarding it. I went with a 220nf output cap and a 500k volume pot. I added a fuzz control ala the fuzzface. I went with some 2n2222's in the mid 200 hfe range. I think it probably could have taken some higher gain trannies but some high end filtering would probably be needed. You'll notice the typical Colorsound one knob fuzz circuit has a 220pf cap from base to collector of the first transistor.
I tried upping the 100r resistor to get some more output but it drastically changes the mid range character of the pedal. Even bumping it to 150r I noticed the cool sort of evil mid scoop disappearing.
From watching footage of the band Budgie I've noticed there's a yellow Colorsound Wah Fuzz Swell onstage sometimes. I think this circuit is pretty consistent with Bourge's tone.

--Brad

Cool! Thanks for the update, Brad!

I just found this link for a mod to this circuit courtesy of Dragonfly. Maybe this is of interest:
https://www.diystompboxes.com/smfforum/ ... ic=27321.0

I found the Stallan schem mentioned earlier.

Yeah that's the one. I've also noticed this circuit responds better to rolling off the guitar volume than the one-knob fuzz circuit. Due to the different feedback biasing resistor value I assume.

--Brad

Looking only at the picture, it looks like the wah section is basically the Colorsound inductor wah circuit. I recently built a clone of that circuit into a gutted Colorsound wah shell, and I love the way it sounds in the lower bass range. It's almost a synthy sounding thing at heel down position, sounds really cool with distortion.

I'm not sure where you hear the volume drop, but I know that on the wah section, you can increase the output level by tweaking the voltage divider at the output. Click here to see how that works: https://img25.imageshack.us/img25/7529/olorsound2.png

Yo

Yeah the Colorsound wah circuit is probably my favorite. I recommend using a 1k trim between Q1's emitter and ground. Works as a sort of intensity control and can dial in the bass a bit. If you don't use lower gain transistors the thing is totally out of control.
The output volume problem I was talking about was specifically about the just the fuzz circuit. I built a standalone version and its pretty quiet. Love the tone though.

--Brad

This might help;