Author Topic: Univox Superfuzz clone question  (Read 1125 times)

Atodovax

Univox Superfuzz clone question
« on: January 01, 2018, 09:14:54 PM »
Hello everybody, im new to the club. I just finished a Univox Superfuzz and posted a video in youtube. Would you mind telling me if it sounds ok, acording to the original unit?
Its ok for me, but i find that it has too much treble and i have never heard the original pedal in real life so i cant be sure if this is the original sound. Im planning to sell this pedal to a friend and i want to be sure that it remains loyal to the univox sound.
Thank you very much!
Here is the link to the video, sorry for the crappy camera on my phone.
The amp im using is a clone of the Soldano Slo50
The guitar ius a gibson sg reissue 61

https://www.youtube.com/watch?v=Z18B3XwP9ww

digi2t

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Re: Univox Superfuzz clone question
« Reply #1 on: January 02, 2018, 08:28:29 AM »
Its ok for me, but i find that it has too much treble...

You do realize that this is an octave up effect? It is the nature of the beast. It sounds about right to me, though tolerances were so loose in these things, the variations could be fairly wide.

Firstly, which schematic did you work from? What transistors did you use? What are your voltages?

Transistor choice can play a huge role in how a Superfuzz performs. My opinion is lower gain is best, staying between 140 and 180. I haven't had the honor of peering inside an original unit yet, but I have had the time to acquire and measure plenty of old Japanese 2SC828 Q and R's, and I can tell you that they always tend to be on the low side of their published ranges. Why is this of any importance? Because the higher the gain transistors you use in this circuit, the splattier it will get. Sometimes to the point that striking a chord will cause a blast of hiss to emanate from your speakers before the chord appears.

If the octave up is just too crazy for you, and you didn't install a 10k balancing trimmer between the Q4/Q5 pair, might be a good idea to put one in (see; Unicord Superfuzz). You can then tweak the trimmer a bit to dial back the octave a tad. The trimmer is really there to manage mismatched transistor pairs, but it does offer the advantage of tweaking the octave output a bit. My weapon of choice here is the 2N2913 dual NPN can. It offers a matched pair of transistors in a single package, but sifting through a bunch of 2N2222's or 2N3904's to match up and audition for THE pair will work too. I'm just lazy.

Personally, I find the clipping diodes direct to ground compressed the sound too much, so lifting these a bit helps open things up, especially where chords are concerned. I like about 1K, but YMMV.

I also replaced the 15K resistor on Q6 base with a trimmer. I've read the original units tended to be be in the 5.6v neighbourhood on Q6 collector voltage, so a trimmer helps dial this in, which also helps give the sound a bit more body. Again, this points to how low the gain of the transistors in the original units really were. Using a 2N2222, or 2N3904, will tend to show between 3 and 4 volts here. These tend to be my transistors of choice for a Superfuzz, so tweaking the collector resistor might be necessary if you really want to get fussy about it.

All in all, your Superfuzz sounds like.... a Superfuzz. Hard to hear the nuances through the ubernet, but then again, it's really not a "nuance" pedal. :icon_biggrin:
« Last Edit: January 03, 2018, 06:21:00 AM by digi2t »
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iainpunk

Re: Univox Superfuzz clone question
« Reply #2 on: January 02, 2018, 08:45:01 AM »
Hey, welcome to the forum

It actually sounds quite like the one my uncle used to have, the sharpness of the tone comes from the octave up effect.
I know that the tone between 2 of the same univox superfuzz pedals from the same manufacturing date could sound quite different due to shitty quality parts and cheap transistors.

Nice pedal and good looks as well.

Iain
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Atodovax

Re: Univox Superfuzz clone question
« Reply #3 on: January 02, 2018, 09:15:42 AM »
Its ok for me, but i find that it has too much treble...

You do realize that this is an octave up effect? It is the nature of the beast. It sounds about right to me, though tolerances were so loose in these things, the variations could be fairly wide.

Firstly, which schematic did you work from? What transistors did you use? What are your voltages?

Transistor choice can play a huge role in how a Superfuzz performs. My opinion is lower gain is best, staying between 140 and 180. I haven't had the honor of peering inside an original unit yet, but I have had the time to acquire and measure plenty of old Japanese 2SC828 Q and R's, and I can tell you that they always tend to be on the low side of their published ranges. Why is this of any importance? Because the higher the gain transistors you use in this circuit, the splattier it will get. Sometimes to the point that striking a chord will cause a blast of hiss to emanate from your speakers before the chord appears.

If the octave up is just too crazy for you, and you didn't install a 10k balancing trimmer between the Q4/Q5 pair, might be a good idea to put one in (see; Unicord Superfuzz). You can then tweak the trimmer a bit to dial back the octave a tad. The trimmer is really there to manage mismatched transistor pairs, but it does offer the advantage of tweaking the octave output a bit. My weapon of choice here is the 2N2913 dual NPN can. It offers a matched pair of transistors in a single package, but sifting through a bunch of 2N2222's or 2N3904's to match up and audition for THE pair will work too. I'm just lazy.

Personally, I find the clipping diodes direct to ground compressed the sound too much, so lifting these a bit helps open things up, especially where chords are concerned. I like about 1K, but YMMV.

I also replaced the 10K resistor on Q6 collector with a trimmer. I've read the original units tended to be be in the 5.6v neighbourhood on Q6 collector voltage, so a trimmer helps dial this in, which also helps give the sound a bit more body. Again, this points to how low the gain of the transistors in the original units really were. Using a 2N2222, or 2N3904, will tend to show between 3 and 4 volts here. These tend to be my transistors of choice for a Superfuzz, so tweaking the collector resistor might be necessary if you really want to get fussy about it.

All in all, your Superfuzz sounds like.... a Superfuzz. Hard to hear the nuances through the ubernet, but then again, it's really not a "nuance" pedal. :icon_biggrin:

Thank you very much for the reply! Very constructive!.
Im using de GGG layout and put the 10 trimmer to adjust the balance of the octave up. But when i turn the trimmer the sound turns from a nice fuzz tu a fading distorted (or poping) sound with no sustain, like a pedal running out of batteries. Im not sure if this is ok. I really dont realize if the octave up effect is being modified by turning that trimmer, but the sustain of the fuzz really does.
Another thing i would like to know is this.. Im using 2n2222 for all the transistors. I have tried different stores not only in my conuntry but also bought some from china, and i always read hfe s of 300 (aproximately) do you think this is very high? i ve read other threads saying that hfe should be lower than 200, but i cant find any other npn transitor below 300 hfe, i tried 2n3409 and others... Or either my DMM is reading higher hfes or i dont know...

digi2t

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Re: Univox Superfuzz clone question
« Reply #4 on: January 02, 2018, 09:56:52 AM »
Yes, 300 is too high. I say this with the following disclaimer; 300 WILL work, no worries there. It's just that I find that it's too high for a... smooth(?) Superfuzz. That is strictly MY opinion, and mine alone. Some folks are perfectly happy with high gain transistors in a Superfuzz. I just don't find them as... manageable.

First things first, if you doubt your DMM as unreliable for testing transistors, then I would remedy that first. Maybe a simple test rig like this on the breadboard to confirm things?



I don't know which country you're in, so I can't comment on where you're sourcing your transistors from. 2N2222's make for great Superfuzz transistors, but as with any transistor, remember that datasheets always provide a range. In the case of the 2N2222, it can be anywhere between 100 and 300. Yup.... pretty big pickin's when you only want transistors around the 140's, but kid, them's the breaks. You need to kiss a lot of frogs to find the prince. Besides that, it also depends on the lot that your supplier(s) bought from their supplier(s). This month's batch might be all high, while next month's batch might be all low. In the end, that's why the tolerance is set by the manufacturer. It ensures a certain consistency for most applications, though your ears (and wallet) might be less happy with the results.

The trimmer is a very subtle thing. Yes, it will adjust the octave effect to some degree, in the middle of it's range, but cranking it all the way one way or the other will adversely affect the circuit on a whole by pulling one of the pair bases to ground, as you pointed out. Start with it dead center, and a nudge one way or the other will give you the desired result BUT... Q4 and Q5 gain should be closely matched to start with. The trimmer is only there to help out for slight mis-match between them. If you already have a matched set in there, and your trimmer at mid way, the best way I find to adjust by ear is to pump a constant 200Hz signal through the circuit, and listen to it through the amp. Nudging the trimmer, you will hear it alter the octave slightly. Set to taste.
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Atodovax

Re: Univox Superfuzz clone question
« Reply #5 on: January 02, 2018, 10:14:17 AM »
Yes, 300 is too high. I say this with the following disclaimer; 300 WILL work, no worries there. It's just that I find that it's too high for a... smooth(?) Superfuzz. That is strictly MY opinion, and mine alone. Some folks are perfectly happy with high gain transistors in a Superfuzz. I just don't find them as... manageable.

First things first, if you doubt your DMM as unreliable for testing transistors, then I would remedy that first. Maybe a simple test rig like this on the breadboard to confirm things?



 
I don't know which country you're in, so I can't comment on where you're sourcing your transistors from. 2N2222's make for great Superfuzz transistors, but as with any transistor, remember that datasheets always provide a range. In the case of the 2N2222, it can be anywhere between 100 and 300. Yup.... pretty big pickin's when you only want transistors around the 140's, but kid, them's the breaks. You need to kiss a lot of frogs to find the prince. Besides that, it also depends on the lot that your supplier(s) bought from their supplier(s). This month's batch might be all high, while next month's batch might be all low. In the end, that's why the tolerance is set by the manufacturer. It ensures a certain consistency for most applications, though your ears (and wallet) might be less happy with the results.

The trimmer is a very subtle thing. Yes, it will adjust the octave effect to some degree, in the middle of it's range, but cranking it all the way one way or the other will adversely affect the circuit on a whole by pulling one of the pair bases to ground, as you pointed out. Start with it dead center, and a nudge one way or the other will give you the desired result BUT... Q4 and Q5 gain should be closely matched to start with. The trimmer is only there to help out for slight mis-match between them. If you already have a matched set in there, and your trimmer at mid way, the best way I find to adjust by ear is to pump a constant 200Hz signal through the circuit, and listen to it through the amp. Nudging the trimmer, you will hear it alter the octave slightly. Set to taste.

Thanks again!! im going to try that schematic to verify if my DMM is wrong and try to replace the transistors
I live in Argentina, but theres nop problem for me to buy in Usa o china. I bought a assortment kit of transistors from ebay wich brought 2n2222 and 2n3409 but both are over 300hfe
Im going to buy some from small bear electronics now and see what happens.

duck_arse

Re: Univox Superfuzz clone question
« Reply #6 on: January 03, 2018, 09:40:18 AM »
I was going to say "the 2N3053 driver transistor might be a candidate for low gain", then I went and looked for them. and found the smallbear page. looks like plenty of options there.

http://www.smallbear-electronics.mybigcommerce.com/search.php?search_query=2n3053&x=0&y=0

it is possible to tune the octave trimmer by the null in the noise/hiss you'll hear with the input shorted. but it turns out to be a double null, and I can't remember which is which.
winter. booo.

Mark Hammer

Re: Univox Superfuzz clone question
« Reply #7 on: January 03, 2018, 03:52:43 PM »
First, a VERY nice build, cosmetically.  I tip my hat to you.

Second, Dino/digi2t and I have had discussions about this, and one of the things I have come to the conclusion of is that the diode pair to ground is really intended to artifically produce compression, so that the octave appears to "bloom" after all the initial harmonics fall away.  That is one of the flaws of many octave-up fuzzes, including the Superfuzz.  There IS octaving right away, but there are so many harmonics in the pick attack, that the octave is hard to hear.  It becomes easier to hear as the strong dies down and the harmonics disappear, leaving mostly fundamental...which is doubled by the circuit.  The diode pair "clamps" the output level so that it appears to remain the same from initial pick attack to later sustain.  If there were no diodes, we would all probably turn the volume way down to compensate, and the note would seem to disappear before the octave arrives.  You can try this with just about any octave-up fuzz.  You will still hear lots of fuzz, but the octave will be harder to make out.

Although the diode pair make a cheap and simple compressor and are not necessary for fuzz, they end up producing some distortion.  So Dino's compromise is a sensible one.  A small resistance keeps most of the compression function, but reduces the clipping produced by the diodes.  One thing you can do to "soften" the tone, in addition to the transistor changes Dino suggests, is to simply insert a small capacitor to ground, in parallel with the diode pair (and added 1k resistor).  A 1000pf cap is probably a good place to start.

Note that you will find different versions of the Superfuzz notch filter posted around.  They will generally have a 10k/22k resistor pair with 0.1uf cap to ground from their junction and a 1000pf bypass cap.  HOWEVER, some will show the 10k first, and others will show the 22k first.  The notch created by 10k->22k starts a bit higher (roughly 160hz) than that created by 22k->10k (roughly 72hz), and will have more "body".

Atodovax

Re: Univox Superfuzz clone question
« Reply #8 on: January 04, 2018, 08:18:43 AM »
First, a VERY nice build, cosmetically.  I tip my hat to you.

Second, Dino/digi2t and I have had discussions about this, and one of the things I have come to the conclusion of is that the diode pair to ground is really intended to artifically produce compression, so that the octave appears to "bloom" after all the initial harmonics fall away.  That is one of the flaws of many octave-up fuzzes, including the Superfuzz.  There IS octaving right away, but there are so many harmonics in the pick attack, that the octave is hard to hear.  It becomes easier to hear as the strong dies down and the harmonics disappear, leaving mostly fundamental...which is doubled by the circuit.  The diode pair "clamps" the output level so that it appears to remain the same from initial pick attack to later sustain.  If there were no diodes, we would all probably turn the volume way down to compensate, and the note would seem to disappear before the octave arrives.  You can try this with just about any octave-up fuzz.  You will still hear lots of fuzz, but the octave will be harder to make out.

Although the diode pair make a cheap and simple compressor and are not necessary for fuzz, they end up producing some distortion.  So Dino's compromise is a sensible one.  A small resistance keeps most of the compression function, but reduces the clipping produced by the diodes.  One thing you can do to "soften" the tone, in addition to the transistor changes Dino suggests, is to simply insert a small capacitor to ground, in parallel with the diode pair (and added 1k resistor).  A 1000pf cap is probably a good place to start.

Note that you will find different versions of the Superfuzz notch filter posted around.  They will generally have a 10k/22k resistor pair with 0.1uf cap to ground from their junction and a 1000pf bypass cap.  HOWEVER, some will show the 10k first, and others will show the 22k first.  The notch created by 10k->22k starts a bit higher (roughly 160hz) than that created by 22k->10k (roughly 72hz), and will have more "body".

Thank you for the reply!! Im on vacations now but will try all this mods once i get home! Do you thnk i should try this along with swtching the transistors , or will the low hfe s will do by themselves?

Mark Hammer

Re: Univox Superfuzz clone question
« Reply #9 on: January 04, 2018, 10:13:57 AM »
Because everything is doubled by the circuit, you are going to get lots offizz in the midscoop tone setting, whether you switch transistors or not.  I suspect you'll get somewhat less, following Dino's transistor recommendation, but you'll still get fizz.  If you used germanium diodes for the clipping/clamping pair, then the hard clipping created by diodes with a low forward voltage introduces even more fizz, so the recommendation to insert the resistor is wise, since it softens the clipping produced by those diodes.  If you still find it too fizzy, then you can try the added cap I suggested.

Atodovax

Re: Univox Superfuzz clone question
« Reply #10 on: January 07, 2018, 10:43:12 PM »
Because everything is doubled by the circuit, you are going to get lots offizz in the midscoop tone setting, whether you switch transistors or not.  I suspect you'll get somewhat less, following Dino's transistor recommendation, but you'll still get fizz.  If you used germanium diodes for the clipping/clamping pair, then the hard clipping created by diodes with a low forward voltage introduces even more fizz, so the recommendation to insert the resistor is wise, since it softens the clipping produced by those diodes.  If you still find it too fizzy, then you can try the added cap I suggested.

Thank you!! I will try every option once i get home from vacations and tell you how it went, i really apreciate all the help. :)

Keppy

Re: Univox Superfuzz clone question
« Reply #11 on: January 08, 2018, 12:54:43 AM »
My weapon of choice here is the 2N2913 dual NPN can. It offers a matched pair of transistors in a single package.

Mind sharing where you get these? A quick search didn't turn up any available at Smallbear, Mouser, or DigiKey.
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Mark Hammer

Re: Univox Superfuzz clone question
« Reply #12 on: January 08, 2018, 12:05:11 PM »
I've been curious about use of a CA3046, which has 5 NPN transistors, two of which share a common emitter (which poses no obstacles for the Superfuzz design), with a typical hfe of 100.

pinkjimiphoton

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Re: Univox Superfuzz clone question
« Reply #13 on: January 08, 2018, 02:29:36 PM »
i've owned a bunch of these over the years and always sold them for a significant markup.
mostly the orange and blue ones.
i prefer the 2sc828's in them, but i agree with dino, anything 200 or under should work fairly well
that said, my last one (built off the MEK kit) i used 5088's and it sounds absolutely killer.
tonally, yeah, you nailed it.
not the most musical sounding fuzz to some, but paired with a distorted amp a crybaby and a echoplex, you can get some wicked cool tones.

sounds great. i'd leave it the way it is ;)
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Atodovax

Re: Univox Superfuzz clone question
« Reply #14 on: January 09, 2018, 10:01:15 AM »
i've owned a bunch of these over the years and always sold them for a significant markup.
mostly the orange and blue ones.
i prefer the 2sc828's in them, but i agree with dino, anything 200 or under should work fairly well
that said, my last one (built off the MEK kit) i used 5088's and it sounds absolutely killer.
tonally, yeah, you nailed it.
not the most musical sounding fuzz to some, but paired with a distorted amp a crybaby and a echoplex, you can get some wicked cool tones.

sounds great. i'd leave it the way it is ;)u

Thank you very much! Im going to try with new transistors with lower hfe and what mark and dyno suggested and put another video to share the differences so all can hear them.
Do you know by ant chance where i can get npn's within that hfe range? (160 + - ) preferable EBC pinout type.

pinkjimiphoton

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Re: Univox Superfuzz clone question
« Reply #15 on: January 09, 2018, 02:25:58 PM »
i like mouser for parts like that, i use mpsa06. they're about .06 a piece, and the gain is pretty much universally 215. but they're npn,  i forget if that's ok with this circuit. too many fuzzes.

socket and try a bunch. surprising combinations can often be found with spectacular results.
but don't trust SIP sockets. they fail all the time. once ya get what ya like, i always remove the sockets and solder the q's in place.

i learned that when the first overdrive i built for dick wagner arrived dead. the damn transistors had fallen out of the SIP sockets in transit. embarrassing. ;)
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aion

Re: Univox Superfuzz clone question
« Reply #16 on: January 10, 2018, 12:48:43 PM »
but don't trust SIP sockets. they fail all the time. once ya get what ya like, i always remove the sockets and solder the q's in place.

You can also take a shortcut and just solder the transistor directly to the socket. This helps when working with double-sided boards that are harder to desolder, or when the PCB is already in the enclosure and you don't want to take it out. You can also solder just one leg to make it easier to swap out later - as long as the other two legs are making solid contact with the sockets.

But yeah, never trust a SIL socket by itself.
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pinkjimiphoton

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Re: Univox Superfuzz clone question
« Reply #17 on: January 10, 2018, 03:01:13 PM »
i've done that, too, but it seems better to just tack solder the sockets in and then remove them. the circuit stability is just too dicey with them lousy SIP's everybody sells. once ya swap a couple q's, they're absolutelty worthless. you can solder the legs in, i've done that too, but in the end i find removing them and just hard soldering them in is faster, better, and way less time trying to figure out what just failed... and it always being a socket ;)

just me, ymmv ;)
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