freestompboxes.org

Thought I would post some pics of the fairly rare Musicians Sound Design Paranoid fuzz. It's a good sounding pedal that gets close to some Sabbath type tones. Good for Smashing Pumpkins stuff too. It's pretty fuzzy and big muff sounding, but a bit tighter and more focused low end. Pretty well built pedal.

The one thing the pedal could use improving on is the output level volume. It's pretty low, just barely reaches unity with the volume all the way up.

If anyone needs any additional pics let me know and I will take them. I don't have the best camera, but I tried to take photos as well as I could.

I admittedly don't have the best knowledge of all the parts and such as I'm not a DIY'er (wish I was but I can never get my head around certain aspects of pedal building).
Some of the markings that aren't visible in the pics:
5 small electrolytic - 2.2uf 50v
1 electrolytic - 100uf 25v
1 electrolytic - 22uf
Small OpAmp - TI TLO62CP
Big OpAmp 14 pin - unmarked

http:847.aeshack.us8474859dsc08252l.jpg
http:401.aeshack.us4017779dsc08242x.jpg
http:834.aeshack.us8344041dsc08264h.jpg

proprietary fuzz chip FOR THE WIN!

I bet it's a CD4049, and a EH Hot Tubes derivative (clamping and/or nfb diodes added)

yeah, that's what I was thinking. 4049. why bother sanding? if anyone has time to trace it, I wouldn't mind seeing a schematic.

By the way the resistors are set up between the pins, it does indeed look like a 4049 or other inverter circuit.

Someone should trace this and make a layout. It's a great sounding pedal. Here's a demo someone did on youtube:


If anyone needs some additional pics and/or values let me know.

Why 100 closeup pics if the top of the PCB and only one, in a poor angle, of the bottom?

yeah i agree with you dirk clearly they don't want the board traced with that type of picture taking

Ok guys, I got one of these pedals in a trade for something I built. And the chip had been sanded, but not sanded enough. I pot a drop of isopropyl alcohol on it and under the right light was able to make out the chip part number.
It's an MC33179P - a quad low power, low noise opamp.
I'll take some photos of the circuit boards tomorrow and post them. It would be nice to get this traced considering Sabbath are doing a re-union tour soon.

Considering this op-amp is obsolete, the LM837 might be a good replacement.

Anyone interested in tracing this, my skills at deciphering it and drawing up a circuit diagram are not the best.

Here's some component values
Edit: Larg electro at top should be 470uF

Unmarked chip is MC33179P - a quad low power, low noise opamp
Smaller chip - TL062

What's connected to the connector? The controls I assume. Do you have pics of that too?

Dirk_Hendrik wrote:What's connected to the connector? The controls I assume. Do you have pics of that too?

Yes, the controls, will get some values and pics up soon.

Here's a couple of pics of the control board.

Pots are 20kA, 100kB and 20kB

Pyr0 wrote:Here's some component values

PF-components.PNG

Edit: Larg electro at top should be 470uF

Unmarked chip is MC33179P - a quad low power, low noise opamp
Smaller chip - TL062

I forgot the resistor to the left of the connector at the bottom left - it is 220R

Thanks so far! Am I correct there's 2 components next to the switch, probably half inder the switch?

Dirk_Hendrik wrote:Thanks so far! Am I correct there's 2 components next to the switch, probably half inder the switch?

Yes, there are 4 holes for components, but two are empty and the bottom two have a 470k resistor, it is on the right hand side of the switch in my pics, wired between middle and bottom lugs of the switch.
Also, the input jack is on the left, output on the right when looking at the component side.

Let's give it some time on a cold and grey November afternoon.

Thanks Dirk, good work. So it kind of looks like an op-amp based big muff,