# Help! Volume drop on an old (70's) Univox Super-Fuzz!!



## co-intelpro (Jan 11, 2008)

Last week, I bought an old 70's Univox Super-Fuzz for a killer price. It had a bum 9V clip, so I replaced it. All is well, but the volume of the effect doesn't reach unity gain, let alone get any louder. My amp has to be cranked for me to hear the darn thing! Anyone know what might be the problem? How can I make this thing louder?

The bypassed signal is WAY louder than the effect. I have a fresh battery in there, so it's not that. Any ideas? Help!


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## keto (May 23, 2006)

If there are electrolytic (stand up barrel/rod shaped) capacitors, they could be dried out and in need of replacement. Could be just a cold solder joint that needs touching up. I'd look at it for you, but it's a long drive =P

Couldn't hurt to post pic(s) of the circuit board, both sides if possible.


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## mhammer (Nov 30, 2007)

Keto's advice is to be heeded. Dried out electrolytics capacitors are a frequent source of disfunctionality in pedals 30 years of age and older. Happily, the Superfuzz uses pretty much the same value of electrolytic capacitor throughout (10uf), which means you can buy yourself a bag of them atActive or some similar place for $5 or less. 

When replacing them, be mindful to:

1) Observe proper orientation of the caps with respect to +/-.

2) Avoid overheating the solder pads when desoldering the existing caps.

Having said that, I will note some other possibilities. 

The ways of stereo input jacks are mysterious. I have been building this stuff for decades now, and I still find myself accidentally soldering the black/ground wire of battery snaps to the wrong lug on the input jack, simply because the layout of lugs is not universal or consistent. When you do that, the battery is not switched off after unplugging. End result is that you go the plug in the pedal the nextday, and you can't get diddley squat out of it because the battery has been running all night long.

It is also the case that PCBs on those older Univox pedals (heck, a LOT of older pedals) are positively drenched in solder. Easy to inadvertently create a solder bridge from one pad to another without realizing it. Under such circumstances, I often recommend to take an old discarded toothbrush, dab some methyl hydrate on it, and brush the copper side of the board. The methyl hydrate will dissolve the flux. Once dissolved, you can pat it dry with a paper towel. The flux itself is not a problem. However, when looking for solder bridges, the flux poses a visual distraction/interference due to its shininess. With the flux removed, it becomes easier to spot irregularities on the board.

While we have your attention, check out this site: uzzfay

This site has some great shots of a number of Superfuzz issues, both component and copper side, that may help to identify how the board should look, and what wires go where.

It could be the aged caps, but it's best to look for causes that necessitate less invasive treatments first.


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## co-intelpro (Jan 11, 2008)

Thanks guys. I've looked through everything, and it all looks good to me (but I'm no expert). I'm thinking it's the caps. My local L&M guy could likely do it. Last time I tried soldering my pedals, I burnt a pad (lousy radio shack soldering iron).


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## mhammer (Nov 30, 2007)

Desoldering is actually relatively easy. For years (nay, decades), I was a firm believer in solder suckers. More recently, though, especially as components get smaller and layouts get tighter, the big pads with blobs of solder that were friendly to solder suckers in past have turned into small eficient dots of solder. As a result, solder suckers do not have enough precision to do what you need (remove all the solder efficiently), and for a variey of reasons, you end up overheating the solder pad and component, and THAT'S where you get damage to the board and components.

Here is what to do instead:

1) Make sure the board is cleaned of dust or any other residue sitting over top of the solder. You can pick up cheap stiff bristle brushes at dollar stores to clean that off.

2) Your soldering iron should have a nice pointy tip. Soldering guns with that thick wire loop are fine for working on amps or household plumbing, but not for PCBs. If you have a budget soldering iron with a big ugly tip, try filing it down to a nice point. If you do file it down, be sure to tin it right away.

3) Get yourself a small spool of desolderng braid (often called "solder wick"). Costlier, at first glance, than a solder sucker, but it does a much better job, and leaves a clean surface. I generally "help out" the solder wick by smearing a small bit of liquid rosin on it. Makes the stuff work like gangbusters. Especially helpful is the manner in which it gets rid of "solder webs", between the component lead and the perimeter of the hole, more efefctively than solder suckers.

4) Once you have removed the solder, clean up flux residue off the board with a small toothbrush and some methyl hydrate.

The liquid rosin will set you back about $8-10 for a small bottle but should last you for your life. The methyl hydrate is something you may already have in your garage, but a small bottle shouldn't be more than a few bucks. Solder wick is between $-5 for a spool. A repair to the pedal will cost you at least a half hour of bench time, which will be more than the cost of the requisite materials.


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## Solid_Gold_Soundlabs (Sep 20, 2006)

The old super fuzzes aren't the loudest pedals out there, i usually have to run mine pretty much wide open to get a decent output level. That being said, this is an old pedal that has quite a bit of value, and the circuit board can be delicate (ie lifting/breaking traces). If you're not comfortable with a soldering iron, you might want to take it over to a competent tech.

Cheers!
Greg

SolidGoldFX
[email protected]


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## mhammer (Nov 30, 2007)

The constraints on volume are a function of the germanium diodes used to clip in the later stage. On my own clone, I have a 3-way toggle that gives me either Ge diode clipping, Si diode clipping or no diodes. The difference in final volume between the 3 settings is substantial.


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## Solid_Gold_Soundlabs (Sep 20, 2006)

Agreed, on my Formula 76 i have a compression knob to control the amount of diode clipping. However Ge diodes give the fuzziest, nastiest tones....an extra output gain stage helps.


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## co-intelpro (Jan 11, 2008)

Thanks guys. I brought it to a tech, but he seems reluctant to muck around with it. The pedal actually CUTS volume after engaged. I think it's something other than the germaniums. I have 3 shin-ei fuzz wahs and all of them are way louder than the super-fuzz.


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## mhammer (Nov 30, 2007)

If you want, feel free to direct him my way, via PM. I can talk him through it. This is just too nice a fuzz to have sitting there sidelined.


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