Univox superfuzz issue

[Dawnofzion]

I am having some major issues with a univox superfuzz build. I put this together based on several schematics I found online. It makes an awful squeeling sound when I plug it up and no guitar signal goes through.  Honestly, I'm not sure I have everything hooked up correctly from the board.  If anyone is familiar with this pedal, can you please take a look and let me know if something looks off. 
Also,  can someone possibly mark on my image what should be hooked up where from the PCB?  I just would like to confirm they way I have things hooked up.






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[Dawnofzion]

Anyone have any experience with this PCB and pedal?


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[Stomptown]

Anyone have any experience with this PCB and pedal?


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I'm not familiar with this layout but the jumpers in the pic below seem odd. It may be a good idea to post the layout / schematic for reference (or a link).

Jon

[somnif]

It looks a lot like this layout, which uses a couple jumpers to connect ground planes:



edit: apparently this is nigh identical to the original board, which also used some questionable jumpers http://imgur.com/i0wHf

[somnif]

If that is your layout you appear to be missing a 1nF capacitor between the two transistors on the bottom left of your first pic

[Dawnofzion]

If that is your layout you appear to be missing a 1nF capacitor between the two transistors on the bottom left of your first pic

Is this the capacitor your are referring to?  If so,  I don't see a place on the PCB for it to be installed?

[Dawnofzion]

This is the schematic i used to wire it up, but I'm not sure this is correct. I can't seem to find a wiring schematic for what goes where off the board to confirm if this is correct or not.

also I don't have an on/off switch.  I'm not sure what that is in this diagram. 

[somnif]

Yep, that is the cap I mean. I've circled it in the schematic below:


Looking at vintage examples, it appears to have been placed on the bottom of some boards ( http://imgur.com/i0wHf ) , tops of others ( http://2.bp.blogspot.com/-KVddyGCw5BM/T0D9WPfpSpI/AAAAAAAAA8o/3J5NQUeOnYA/s1600/superfuzz1.jpg nearest the battery).

In the layout I posted there are pads/holes for it to be placed, but your board appears to be missing them. Did you etch/drill the board yourself? Its possible the layout was based on a "bottom of the board" example. If so you can just solder it in parallel with the 47k resistor.

As for the wiring, that is very much a "vintage" scheme. Battery always engaged (hence the on/off switch), no power jack, dpdt switch.

It will work, but I'd suggest looking at some of the vero examples out there for a somewhat more modern take on wiring (and perhaps a  little easier to understand). Checkout the "offboard wiring" sections of Tagboardeffects or the footswitch tutorial here on madbean ( http://www.madbeanpedals.com/tutorials/downloads/MBP_FootswitchWiring.pdf ) for some examples.

[Dawnofzion]

No I didn't etch the board myself. I bought it years ago from someone on the diystompbox forum. 

I wired it up with a 3pdt switch in true bypass and LED.  I didn't use that specific wiring schematic for the switching. 

I will add the cap, but I'm not sure that is the only thing going on. 


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[somnif]

The cap apparently has a fairly minor effect, and correct, wouldn't "kill" the pedal if absent.

Aside from that missing cap, the board itself looks fine. Looks like you're using another NPN transistor, should be fine, as long as you're sure you've got them all in the right way around. I've not checked every single resistor against the schematic, as that is a pain the proverbial, but keep it in mind for trouble shooting down the road.

Can you provide pics of the off board wiring? It's possible you've mis-wired something hence the nastyness.