Univox - Superfuzz  [schematic]

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

This is one of those octafuzzes that has a that great, 'static-ky' timbre. Gated spikes, one might say. I've found that using Ge diodes, like 1N34As, seem to be essential for this particular type of 'spike', in that no other diode types distort in quite the same manner.

Also in my builds: yes, tho - LEDs come pretty close in these circuit types, as ways of creating nearly the same sound, seems stronger & bassier to me.

poodlebra
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Post by poodlebra »

i've some nice 1N34A equivalents if you need them (1N60P - pretty much identical). I was sick of paying £1 each for them so bought a load. sold tons on ebay and everyone rates them. i can't tell the difference when switching between them anyway. http://poodleparts.blogspot.com/

joshwertheimer
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Post by joshwertheimer »

I breadboarded one of these, liked it a lot, and made one. No sound at all. Besides a bad output pot, I found I missed two ground connections, specifically the ones from the emitter and base resistors for Q3 and Q6. Now it works, but doesn't sound very good. More gated than I remember the breadboard sounding. I can't see how, but could I have damaged those two transistors?

I know I could just swap them out, but I'm looking to learn something here. They're PN2222AG.

Thanks.

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Post by DesertCruiser »

Hi folks! My first post here. I made this sweet little piece of fuzz the last weekend on the original grey verision pcb. i put in the components and everyting was looking allright, but when i plugged it in the sound was very low and sounded very strained. allmost a whole day i searched for errors, and i could trace the signal to the octave stage, but then it was allmost gone :scratch: it showed out that there was an error in the schematic: http://www.univox.org/pics/schematics/superfuzz2.gif
The base resistor (22k) to vcc on the trannie on the left in the octave stage and the base resistor (100k) to ground on the trannie on the right had changed position in the schem. I swapped them and everything worked fine. Just wanted to warn you peole for this fatal error :wink:
cheers
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Post by IvIark »

poodlebra wrote:i've some nice 1N34A equivalents if you need them (1N60P - pretty much identical).
They're the schottky 1N60. The germanium 1N60s look like this:

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Post by poodlebra »

they're listed as germanium at the suppliers and it says as much in the spec sheet. only difference i could see was the peak reverse voltage (45 instead of 70). I wouldn't pretend to know a great deal about it, but they sound good to me, and i've had no complaints from the 20+ people who've bought them.

the 1N34A i've bought previously weren't in that kind of case anyway. both from bitsbox and farnell, they were in a black housing similar to 1N400X.

i'd be grateful for any info on how the ones i've got differ from any others. i live to learn.

cheers.

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Post by IvIark »

Yes Futurlec lists them as germanium too, but what they have in the datasheet associated with the product isn't what you get. Their diodes are DO35 packages and yet the datasheet shows them as DO7 with a 7.2mm body which is the type in the pic I posted. I even emailed Futurlec about it (and the fact they were supplying Schottky 1N60s when you order 1N34As from them too) and didn't get a reply back.

I've got loads of the schottky types and they are good, but not what they're being sold as by some sources in the far east.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Post by poodlebra »

ok, thanks for that. i'll get off my lazy ass and google 'shottky' eh?

as i said, i've done comparisons between these and the 1N34A i've bought from other sources, and they sound pretty identical to me.

i'm happy to send a few to anyone uk-based if they fancy doing a like-for-like test on something. if they aren't what they're meant to be i'll stop buying them. cheers.

IvIark
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Post by IvIark »

Here's a datasheet showing diode packages. If you ask the supplier for a datasheet for their diodes, it will probably show them as DO7 packages and germanium, or DO35 and schottky. The type I received from Futurlec and the type in your pic were the DO35 package like 1N4148 diodes. I haven't seen any 1N60 datasheets that list the germanium version as anything other than DO7.
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Diode Packages.pdf
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"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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mcaviel
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Post by mcaviel »

so where can we buy a decent germanium diodes ?

BTW IvIark, that is one unique goal :applause:

IvIark
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Post by IvIark »

I got some from here and they are authentic.
Oh and CHICHARITO!!! :mrgreen:
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

Adriansmith90
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Post by Adriansmith90 »

Hello guys! I'm using google translator because I'm not very familiar with your English! So I wanted to expose myself to my problem ... ina few days I built the circuit and I dell'univox superfuzz used as the transistor 2n5088 ... the scheme used is the correct one, the one with the resistance "alternate" of 22k and 100k ... the problem is that when the coupling effect, the sound coming out of the circuit is the clean guitar! He feels, however, if the ex-guitar classic FFFF, to give you an example is like when you turn a distortion but no play, just the sound ... But if you attack the guitar the FFFF background is clean but the sound is not distorted! I am sure that the values of the components are right because I have rechecked many times ... may depend on what you think? I hope I managed to understand me because I know that google translator to translate some bad times :-) I am Italian, if anyone knows how to speak my language I'd understand better haha! :-) I hope you guys help me :-(

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Post by varicose »

Hi, are the electrolytics non-polar?

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Post by Crumbchildz »

Any thoughts on the output level of this circuit? It seems kinda low in my clone.
Loud's a tone, right?

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Post by Bside2234 »

Crumbchildz wrote:Any thoughts on the output level of this circuit? It seems kinda low in my clone.
My guess is something is wrong with yours. Wrong parts value or something like a solder bridge or cold solder joint. Mine is crazy loud.

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Crumbchildz
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Post by Crumbchildz »

Fair enough, man. I'll keep diggin!
Loud's a tone, right?

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Crumbchildz
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Post by Crumbchildz »

I should note that I replaced the tone switch with a 100k linear pot and I used BC109's in place of 2SC539's. Could those changes contribute to the lack of volume? It sounds great, but it's just kinda quiet.
Loud's a tone, right?

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Post by Bside2234 »

Crumbchildz wrote:I should note that I replaced the tone switch with a 100k linear pot and I used BC109's in place of 2SC539's. Could those changes contribute to the lack of volume? It sounds great, but it's just kinda quiet.
It's probably a good idea to try the circuit stock to make sure it's working properly before you start modifying things.

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Crumbchildz
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Post by Crumbchildz »

Thanks for that.
Loud's a tone, right?

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Post by Thaxt »

The 1N34A's which I got from Mouser , ca 2002, & which sport a black polarity indicator line seem to have a much heavier & stronger sound than the ones I've gotten more recently which have a green polarity line.

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