Univox - Superfuzz  [schematic]

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

Re: Univox - Superfuzz - Question for Derringer on his mods

Postby kzustang » 12 Apr 2014, 16:52

derringer wrote:
Thaxt wrote:I think the 1N34A diodes - or the OA-90s - weaken this pedal's sound when they are direct to ground; the AMZ warp mod - placing a 10 K pot between diodes & ground - seems a key to getting both better volume & fuzz texture.

I've tried the stock configuration, & it does come off as way too weak...hissy & fuzzy, but (IMO) not a strong fuzz.

LED's as subs do tend to hit pretty hard, but the usual other diode subs can do wonders, & bring out the UVSF's innate, characteristic sounds.

Modding the midscoop is key too. Modding those 2 things can get you a whole 'nuther Superfuzz, meaning: in a good way.

The (overly?) scooped, meek & fizzy can become: WOW! The scoop is great for bass tho.


and that's pretty much what I did for my superfuzz build
[ Image ]
[ Image ]

and it's been on my pedalboard around 3 years now, love this thing


I there.
Trying to build the Derringer layout with the added mods:
1. Can anyone comment on the Scoop cap - is it 56nF or 560nF. Not really sure here based on the fact that the layout and schematic do differ in that value.
2. Can anyone comment based on the Derringer layout if the Scoop Control alters the sound in a way which enhances the original or changes the original? I would have loved to have the Scoop Control having the original sound on both ends of the knob while the intermediate positions are somewhere between.

Thanks,
Zustang
______________________________________________________________________________
K. Zustang

create something greater, something uncontainable. Make sure you are at a constant motion forward...
kzustang
 
Posts: 18
Joined: 21 Nov 2010, 22:43
Location: Israel
Has thanked: 4 times
Have thanks: 2 times

Re: Univox - Superfuzz

Postby derringer » 12 Apr 2014, 18:20

man ... I never noticed the discrepancy. Good eye.

It should be 56nF as per the schematic and not the vero picture.

The original uses 100nF and that produced too much scoop to my ears. One could easily wire a switch to vary between 56nf and 100nf caps.

The scoop control does give you the "notch" sound when the pot is turned to zero. I imagine when the pot is at 10K then you should have next to zero scoop happening which would give you the "normal" sound. You could try a 25K pot in there to see if 25K or resistance between C13 and ground sounds any different from 10K of resistance ... which would mean go with the larger resistance.

Another option would be to use an on-off-on toggle to switch between 56 nF, open circuit to the scoop pot, and 100nF.

I think you may still be getting a little extra bit of hi frequencies though as in my design, the signal would still has to pass through the 0.001uf cap and the lows would be slightly slowed down through the 22k+10k resistors before the final gain stage. But then I have the hi freq cut cap on the last gain stage too.

It's up to what sounds best to your ears, and how picky your ears may be, in the end.

Follow up. I'd like to know your thoughts when you build it.

For this message the author derringer has received thanks:
aishabag23 (04 Oct 2014, 18:09)
derringer
 
Posts: 22
Joined: 27 Sep 2009, 14:07
Has thanked: 5 times
Have thanks: 11 times

Re: Univox - Superfuzz

Postby kzustang » 12 Apr 2014, 18:49

derringer wrote:man ... I never noticed the discrepancy. Good eye.

It should be 56nF as per the schematic and not the vero picture.

The original uses 100nF and that produced too much scoop to my ears. One could easily wire a switch to vary between 56nf and 100nf caps.

The scoop control does give you the "notch" sound when the pot is turned to zero. I imagine when the pot is at 10K then you should have next to zero scoop happening which would give you the "normal" sound. You could try a 25K pot in there to see if 25K or resistance between C13 and ground sounds any different from 10K of resistance ... which would mean go with the larger resistance.

Another option would be to use an on-off-on toggle to switch between 56 nF, open circuit to the scoop pot, and 100nF.

I think you may still be getting a little extra bit of hi frequencies though as in my design, the signal would still has to pass through the 0.001uf cap and the lows would be slightly slowed down through the 22k+10k resistors before the final gain stage. But then I have the hi freq cut cap on the last gain stage too.

It's up to what sounds best to your ears, and how picky your ears may be, in the end.

Follow up. I'd like to know your thoughts when you build it.


Thank you so much.
Building this right now. I am using your schematic and modding accordingly the IVIark / Mirosol layout on the GuitarFXlayouts blog.

Zustang
______________________________________________________________________________
K. Zustang

create something greater, something uncontainable. Make sure you are at a constant motion forward...
kzustang
 
Posts: 18
Joined: 21 Nov 2010, 22:43
Location: Israel
Has thanked: 4 times
Have thanks: 2 times

Re: Univox - Superfuzz

Postby derringer » 12 Apr 2014, 18:53

why not just use my layout that already has the mods figured into it?
derringer
 
Posts: 22
Joined: 27 Sep 2009, 14:07
Has thanked: 5 times
Have thanks: 11 times

Re: Univox - Superfuzz

Postby sergiofnm » 01 Sep 2014, 10:57

Hi people...

Yesterday i've finished a superfuzz using the original layout (of uzzfay) the version with no trim pot.

but i i've got a problem.... when the balance is cranked to max the pedal starts to get oscillation noise..... is this normal?
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby kzustang » 01 Sep 2014, 17:13

Derringer, I am using IVIark's layout just because it fits better in my enclosure and because I had the right vero size.
Other than that I think your modifications hugely contribute to the versatility and usability of this beast.

Thanks again.
______________________________________________________________________________
K. Zustang

create something greater, something uncontainable. Make sure you are at a constant motion forward...
kzustang
 
Posts: 18
Joined: 21 Nov 2010, 22:43
Location: Israel
Has thanked: 4 times
Have thanks: 2 times

Re: Univox - Superfuzz

Postby sergiofnm » 02 Sep 2014, 12:09

Any comment about this? please :|


Re: Univox - Superfuzz
Postby sergiofnm » Yesterday, 10:57

Hi people...

Yesterday i've finished a superfuzz using the original layout (of uzzfay) the version with no trim pot.

but i i've got a problem.... when the balance is cranked to max the pedal starts to get oscillation noise..... is this normal?
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby kzustang » 02 Sep 2014, 13:40

I didn't get any oscillations with my build. Which NPN trannys are you using?
______________________________________________________________________________
K. Zustang

create something greater, something uncontainable. Make sure you are at a constant motion forward...
kzustang
 
Posts: 18
Joined: 21 Nov 2010, 22:43
Location: Israel
Has thanked: 4 times
Have thanks: 2 times

Re: Univox - Superfuzz

Postby tabbycat » 02 Sep 2014, 19:05

sergiofnm wrote:Yesterday i've finished a superfuzz using the original layout (of uzzfay) the version with no trim pot.

but i i've got a problem.... when the balance is cranked to max the pedal starts to get oscillation noise..... is this normal?


i built mine from mike livesley's vero layout (no trimmer, as yours) and i have never had any oscillation from it.
my understanding is that the uzzfay layout has been around a while and is generally thought of as ok.

have you carefully double-checked your build:

component values correct?

in correct positions on the layout?

are you sure the pin-outs on your transistors correspond with those on your layout? that's really important and that's what caught me out when i built mine. it seems a very easy mistake to make, though it was my first build.

track cuts in right place? no solder spills making connections it shouldn't? (run a knife along lines between copper strips to break accidental solder links and check your track cuts really have cut).

and how sure are you that your off-board (pots, switches, jacks, etc) wiring is correct?

if you've throroughly double-checked it and still not found a problem, can you post a link here to the exact layout you used? and we can go from there.

don't panic or despair. or get annoyed with it (or yourself). or think you must have got it right because you don't make simple mistakes. we all do.
just carefully check it through with the same detachment you would apply if you were looking at something someone else built. and if you don't find anything immediately wrong with your build, post back and we can go from there.

ok?
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).
User avatar
tabbycat
Cap Cooler
 
Posts: 518
Joined: 03 Jul 2011, 01:09
Location: i could tell you but i'd have to kill you.
Has thanked: 227 times
Have thanks: 63 times

Re: Univox - Superfuzz

Postby sergiofnm » 02 Sep 2014, 21:57

tabbycat wrote:
sergiofnm wrote:Yesterday i've finished a superfuzz using the original layout (of uzzfay) the version with no trim pot.

but i i've got a problem.... when the balance is cranked to max the pedal starts to get oscillation noise..... is this normal?


i built mine from mike livesley's vero layout (no trimmer, as yours) and i have never had any oscillation from it.
my understanding is that the uzzfay layout has been around a while and is generally thought of as ok.

have you carefully double-checked your build:

component values correct?

in correct positions on the layout?

are you sure the pin-outs on your transistors correspond with those on your layout? that's really important and that's what caught me out when i built mine. it seems a very easy mistake to make, though it was my first build.

track cuts in right place? no solder spills making connections it shouldn't? (run a knife along lines between copper strips to break accidental solder links and check your track cuts really have cut).

and how sure are you that your off-board (pots, switches, jacks, etc) wiring is correct?

if you've throroughly double-checked it and still not found a problem, can you post a link here to the exact layout you used? and we can go from there.

don't panic or despair. or get annoyed with it (or yourself). or think you must have got it right because you don't make simple mistakes. we all do.
just carefully check it through with the same detachment you would apply if you were looking at something someone else built. and if you don't find anything immediately wrong with your build, post back and we can go from there.

ok?



no problem friend :) not desparing :)

the pedal works .... fantastic fuzz tone but.... just that issue.... one that I don't know if its a caracheteristic of the pedal it iself....

when expander is full max.... if i put balance higer (say 12 o'clock til max) starts a big noise.... squeal noise.... especially if strings muted.

all components alright .. all traces good, no cuts or bridges... transistors ok, (well.... put it all 2sc828.... i know that 4 of them in the schem should be 2sc539).... the diodes are not Germanium also.... should that be the problem origin?
You do not have the required permissions to view the files attached to this post.
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby kzustang » 02 Sep 2014, 23:24

Did you make sure the 2C828 are all on the correct BEC side? That is the only thing I can think of. Do you have the voltage readings on all of them?
______________________________________________________________________________
K. Zustang

create something greater, something uncontainable. Make sure you are at a constant motion forward...

For this message the author kzustang has received thanks:
sergiofnm (03 Sep 2014, 00:17)
kzustang
 
Posts: 18
Joined: 21 Nov 2010, 22:43
Location: Israel
Has thanked: 4 times
Have thanks: 2 times

Re: Univox - Superfuzz

Postby tabbycat » 02 Sep 2014, 23:54

sergiofnm wrote:the pedal works .... fantastic fuzz tone but.... just that issue.... one that I don't know if its a caracheteristic of the pedal it iself....

when expander is full max.... if i put balance higer (say 12 o'clock til max) starts a big noise.... squeal noise.... especially if strings muted.

all components alright .. all traces good, no cuts or bridges... transistors ok, (well.... put it all 2sc828.... i know that 4 of them in the schem should be 2sc539).... the diodes are not Germanium also.... should that be the problem origin?

i do have to stress that i'm not an expert of any desciption (a relative newbie in fact) and other members here will certainly be able to apply far more expereince and wisom to your problem than i can offer, but i can tell you what i would try for all it's worth?

the 2sc828 and the 2sc539 have the same pin out so that shouldn't be a problem.

i used 1n34a instead of oa91 (as i remember). haven't tried building it with silicon diodes so i'm not sure how that might effect things. someone else may be able to comment there...

but it sounds as if some part of your signal is being recycled (causing the self-oscillating) where it shouldn't.
so have you tried checking the output at the various stages in the circuit?
if you test the output of the circuit from between the octave pair and the clipping diodes (before the clipping diodes, tone stack and final gain stage) and there is no oscillation, then work along the circuit, testing after the clipping diodes, then after the tone stack, until it appears, that should tell you where the problem lies, which should give you a big clue to what it could be. if you've got a length of wire with a crocodile clip on each end that will work as a jumper to do the job.

if you are testing i'd recommend not putting it through a 100w stack (or headphones, unless you are a masochist) but using a little amp that will just give you enough volume to tell you what you need to know.

again, i am not an expert, but this is quite a quick and painless way to work out which part of your circuit is recycling your signal to give you the squeal. and with that information you can focus your efforts (and efforts of members here wiser than myself) on a smaller (so easier to address) problem.
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).

For this message the author tabbycat has received thanks:
sergiofnm (03 Sep 2014, 00:18)
User avatar
tabbycat
Cap Cooler
 
Posts: 518
Joined: 03 Jul 2011, 01:09
Location: i could tell you but i'd have to kill you.
Has thanked: 227 times
Have thanks: 63 times

Re: Univox - Superfuzz

Postby sergiofnm » 03 Sep 2014, 00:08

kzustang wrote:Did you make sure the 2C828 are all on the correct BEC side? That is the only thing I can think of. Do you have the voltage readings on all of them?



Pinout is ok kzustang :) allways triple check before mount them
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby sergiofnm » 03 Sep 2014, 00:14

tabbycat wrote:
sergiofnm wrote:the pedal works .... fantastic fuzz tone but.... just that issue.... one that I don't know if its a caracheteristic of the pedal it iself....

when expander is full max.... if i put balance higer (say 12 o'clock til max) starts a big noise.... squeal noise.... especially if strings muted.

all components alright .. all traces good, no cuts or bridges... transistors ok, (well.... put it all 2sc828.... i know that 4 of them in the schem should be 2sc539).... the diodes are not Germanium also.... should that be the problem origin?

i do have to stress that i'm not an expert of any desciption (a relative newbie in fact) and other members here will certainly be able to apply far more expereince and wisom to your problem than i can offer, but i can tell you what i would try for all it's worth?

the 2sc828 and the 2sc539 have the same pin out so that shouldn't be a problem.

i used 1n34a instead of oa91 (as i remember). haven't tried building it with silicon diodes so i'm not sure how that might effect things. someone else may be able to comment there...

but it sounds as if some part of your signal is being recycled (causing the self-oscillating) where it shouldn't.
so have you tried checking the output at the various stages in the circuit?
if you test the output of the circuit from between the octave pair and the clipping diodes (before the clipping diodes, tone stack and final gain stage) and there is no oscillation, then work along the circuit, testing after the clipping diodes, then after the tone stack, until it appears, that should tell you where the problem lies, which should give you a big clue to what it could be. if you've got a length of wire with a crocodile clip on each end that will work as a jumper to do the job.

if you are testing i'd recommend not putting it through a 100w stack (or headphones, unless you are a masochist) but using a little amp that will just give you enough volume to tell you what you need to know.

again, i am not an expert, but this is quite a quick and painless way to work out which part of your circuit is recycling your signal to give you the squeal. and with that information you can focus your efforts (and efforts of members here wiser than myself) on a smaller (so easier to address) problem.



oh well....

as i could figure by now is that the pedal was not suposed to do that...

first off... i'll put on it ge diodes and see what will happen...

then substitute two of the caps that are ceramic for mylar ones...

and then... try to test with probe ..... is that i'm a total noob in the matter...

this is my 4.th build, other threen perfect (small clone, a big muff and a fender blender) but this one has been a pain for me...


many thanks :)
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby tabbycat » 03 Sep 2014, 02:23

my best guess would be that a component that is supposed to be going to ground has been connected back into the circuit somewhere (by mistake or in a way that you can't see yet). so instead of that unwanted excess signal being removed from the circuit and dumped, it is just spinning around and around it.
if that seems a reasonable guess to you then systematically jumping sections out of the circuit until the oscillation is no longer present will narrow down your search for that potential rogue mis-grounded part.

but this idea or suggestion comes with the proviso that i have only built four pedals myself. though i have read quite a bit into what is going on in the circuits i built, so my understanding of basic princples is getting there. but that seems logical.

if you get fed up of trouble shooting and don't mind a vero build (may even save time if your build has a freaky and osbcure glitch) there are three standard superfuzz trustworthy layouts i know of that i can recommend.

mike livesley's build (in this thread, page 4). i built this for a first build (wildly ambitious but got away with it with care, patience and persistence). it's the basic univox superfuzz. sounds amazing.
http://img.photobucket.com/albums/v48/MikeyJazz/superfuzz.gif

IvIark's layout (he's here and at the excellent tagboardeffects site). again the basic univox superfuzz.
http://tagboardeffects.blogspot.co.uk/2012/01/univox-super-fuzz.html

mirasol's layout (here and at the excellent tagboardeffects site). the basic univox superfuzz wth the octave trimmer (came as standard on some superfuzzes).
http://tagboardeffects.blogspot.co.uk/2013/12/unicordunivox-super-fuzz.html

and derringer (here, check back a few pages in this thread) has posted a superfuzz vero layout with lots of useful mods built in if you want optimum options.

the good thing with going with any of these builds is that the common problems that arise from building them will be addressed in the posts that follow the posting of the layout.

and if you are not already doing so, definitely socket transistors, diodes and IC/opamps so you can tweak those vital components easily until you are ready to box up. that is one of the best bits of advice i got here (and luckily early on).

i hope you get there one way or another.
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).

For this message the author tabbycat has received thanks:
modman (04 Sep 2014, 08:59)
User avatar
tabbycat
Cap Cooler
 
Posts: 518
Joined: 03 Jul 2011, 01:09
Location: i could tell you but i'd have to kill you.
Has thanked: 227 times
Have thanks: 63 times

Re: Univox - Superfuzz

Postby kaycee » 04 Sep 2014, 07:37

What switching are you using for bypass? It's a high gain circuit, you need to have switching that grounds the circuit input on bypass otherwise when it's 'on' you get a feedback loop produces that kind of squeal.
User avatar
kaycee
Solder Soldier
 
Posts: 162
Joined: 16 Mar 2008, 19:04
Has thanked: 31 times
Have thanks: 13 times

Re: Univox - Superfuzz

Postby sergiofnm » 04 Sep 2014, 10:24

hi.... i'm just using the normal bypass switching like the original.. like this image


but, just in the first page of this topic i've came across with this..... maybe after all is normal......



Re: Univox - Superfuzz
Postby Solidhex » 30 Oct 2008, 09:56

With any Superfuzz build expect a delayed blast of hiss about a split second after you hit a note or chord. If you don't like it TOUGH!

--Brad
Solidhex
Resistor Ronker


welll.... going to put the germanium diodes and in another turn going to build the superfuzz from GGG layout .... it has a bubch of mods included
You do not have the required permissions to view the files attached to this post.
sergiofnm
 
Posts: 6
Joined: 05 Mar 2013, 17:16
Has thanked: 2 times
Have thanks: 0 time

Re: Univox - Superfuzz

Postby tabbycat » 10 Feb 2015, 20:03

am revisiting my 2011 build with new learning, supercharging my superfuzz, and have a question re substituting a 'and-something-inbetween' pot for the tone 1 (unscooped) and tone 2 (scooped) switch.

basically there seem to be three ways this unscooped thing has been addressed.

1. standard univox superfuzz layout. two position tone switch, unscooped and scooped.
univox superfuzz.gif

http://ustomp.com/files/superfuzzschem.gif
i like both the one and two positions, they are perfect as they are, so would like to keep them entirely intact, uncompromised and instantly available on the first two options of an on-on-on switch.

for the third on option. i would like to have a blend. the two ways i have seen of doing this are:

2. the derringer scoop mod to the univox superfuzz (on p16 of this thread).
derringer superfuzzMyMods.jpg

full schematic http://i215.photobucket.com/albums/cc24 ... MyMods.jpg
this puts a 10k trimmer/pot between the bottom cap of the scoop stack and ground.
it also omits the 47k and the 10k resistor to ground which is used to balance output of tone 1 to tone 2 in the original univox schematic.

3. the wattson efy-6 (standard univox superfuzz with common mods built in).
Wattson-EFY-6.jpg

full schematic download/file.php?id=22554&mode=view
this takes tone 1 to lug 1 of a 100k pot, tone 2 to lug 3, and takes the wiper to lug 3 of the volume pot (called 'balance' in the original superfuzz and 'gian' on the wattson modded version).
it also changes (doubles) the value of the high pass cap in the scoop.

i've got my superfuzz out of the box and wired up to a breadboard so can play around as far as finding something i think i like using these as starting points, but i wanted to know, from a purely technical perspective, which of the two tone1 and tone 2 blending option will give the most 'authentic' (as in 'true to the intentions of the original circuit') mix of the two tones?

looking at the wattson, the pot will give you one or other tone 'as nature intended' but when the 100k mix pot is in the centre position isn't that adding an extra 50k of resistance to each path. as this is the same for both does this cancel itself out as far as what you can hear and as what can be measured?

looking at the derringer, that loses 47k of resistance on the tone 1 path (unscooped). and is the scoop trimmer a more or less effective means of keeping the original two starting tones but allowing an authentic mix between the two?

and is there another way worth considering not covered by either of these alternatives?

i sort of understand the principle of what is going on in both cases, but not to the fine point of understanding which option blends the two with least compromise, in technical terms. working at the limits of my knowledge here and trying to push through to the next level.

would be grateful if anyone wiser than i (that's pretty much everyone then) wish to make a comment or pass a judgement, or have any thoughts or ideas about what i'm intending to do.

many thanks to derringer and amp surgeon (wattson) for posting their modded schematics here. much appreciated.

tabbycat.
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).
User avatar
tabbycat
Cap Cooler
 
Posts: 518
Joined: 03 Jul 2011, 01:09
Location: i could tell you but i'd have to kill you.
Has thanked: 227 times
Have thanks: 63 times

Re: Univox - Superfuzz

Postby tabbycat » 10 Feb 2015, 20:24

^ 'transparent' is the buzzword i was looking for. a means of mixing from one to the other that adds or takes away as little as possible from the original two tones as intended by the circuit.
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).
User avatar
tabbycat
Cap Cooler
 
Posts: 518
Joined: 03 Jul 2011, 01:09
Location: i could tell you but i'd have to kill you.
Has thanked: 227 times
Have thanks: 63 times

Re: Univox - Superfuzz

Postby kaycee » 11 Feb 2015, 08:35

You could keep the original tone section, and add a tone knob. Taking the output from after the diodes and run it to a pole of a DPDT switch. On one side have the route through the normal tone stack with the two position switch intact. On the other throw you can insert the tone stack of your choice, the other pole of the switch goes to the volume pot.

You can try whatever tone stack you like, I'd suggest the Stupidly Wonderful Tone Control that Jack Orman put out, works quite well on this circuit. Does it cover the ground of the original tone selections? Kind of.

For this message the author kaycee has received thanks:
tabbycat (12 Feb 2015, 01:12)
User avatar
kaycee
Solder Soldier
 
Posts: 162
Joined: 16 Mar 2008, 19:04
Has thanked: 31 times
Have thanks: 13 times

PreviousNext

Return to Vintage Stompbox Corner ( ... - 1975)

Who is online

Users browsing this forum: No registered users and 3 guests