super fuzz

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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Paleoman
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Post by Paleoman »

New member here, and my apologies if i am starting off on the wrong foot with my first post..,.i am hoping someone can provide some advice here as to what may be wrong with an old distortion box. I have an old univox superfuzz stomp box that when plugged in no longer generates a really cool crunch sound it now generates what really sounds like static. . It has two settings but both sound similar, like a static generator. Any ideas? maybe the capacitors need replacing. Afterall it has to be at least 50 years old. I am clueless as to what might be wrong so i welcome any suggestions. Thank you.

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Nocentelli
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Post by Nocentelli »

Welcome to FSB! Very cool that you have an OG Superfuzz. Firstly, I would advise posting this in the section here:

viewforum.php?f=73

...because the circuit analysis section (vintage/modern/boutique) is meant to be dedicated to tracing and documenting the schematics for pedal circuits.

Assuming you've checked basics like the battery is fresh, and the in/out jack connections are not loose, the minimum needed to attempt a remote diagnosis is the voltages at collector, base and emiiter of each transistor. If you have a voltmeter, this is fairly easy, and you can also use it to check continuity of signal, e.g. from input jack to footswitch and between pins of the footswitch. Electrolytic caps can go bad over time, but I get the impression this is a lot less common than internet wisdom suggests, and replacing them all in the hope it will sort the problem may well cause other problems.

Whilst you have the pedal open for exploratory surgery, if you were to take some quality close-up pictures of the circuit board and post them in the official Univox Superfuzz thread below, you would be doing everyone here a massive favour. The thread has a supposedly correct schematic on the first page and LOTS of discussion about building a clone, layouts for a clone etc, but there doesn't seem to be much in the way of actually documentary information from original units: People here could use your pictures to trace it out conclusively rather than rely on the received wisdom of the internet

viewtopic.php?t=3354

Also, diystompboxes.com has a lengthy guide to debugging - It's aimed at debugging DIY projects that don't work, but lots of it is also useful for troubleshooting any defective pedal:

https://www.diystompboxes.com/smfforum/ ... ic=29816.0
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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CheapPedalCollector
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Post by CheapPedalCollector »

I've repaired quite a few of them, the electrolytic caps go bad in them, usually replacing them restores the unit to full functionality.

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