Univox Super Fuzz?

[brokenstarguitar]

Is it possible to switch the tone toggle switch on a univox super fuzz to a pot nd wire the pot like the switch? What kind of mod would work?

[digi2t]

Yeah, put one on mine, works great.

[nate77]

I've done the same, and it really adds a lot of versatility to the pedal

[brokenstarguitar]

is there a Toner Transfer and or board layout anywhere? Ive been looking but i cant seem to find one. 

[digi2t]

is there a Toner Transfer and or board layout anywhere? Ive been looking but i cant seem to find one. 

There is a 600dpi toner transfer board available around here, you'll have to look for it. There's no layout that has the tone in pot form, instead of a switch, to my knowledge. But, I'm sure that you could easily modify the existing transfer layout to work with a pot.

[Mark Hammer]

The tone switch on a stock Superfuzz selects between a midscooped version of the output, and a version which has no tone shaping, and is attenuated to match the level of the midscooped version.

The ZVex Octane - a clone of which can be found here: www.madbeanpedals.com/projects/Poindexter/docs/Poindexter.pdf  - is itself an improved version of the Superfuzz, and uses a variable tone control instead of switch.  That tone control is simply a mid-lift pot that places a variable resistance between the 100nf cap in the midscoop filter, and ground.    Since the midscoop filter provides for highpass through the 1nf (.001uf) cap, and lowpass through the 22k/100nf RC pair. sticking that pot in does nothing for the top end and simply varies how much impact the lowpass side has.  The higher the resistance between that 100nf cap and ground, the less mids are cut.

So, inserting that tone pot will ONLY affect the mids, and do nothing about the highs.  having built one, I will say that it IS effective, but may be less than what you're looking for.

Here's an alternative, that I'm sure I've seen somewhere, so it's not my idea.

You see the 47k/10k pair, whose output the tone switch can select from?  Let's replace the 47k resistor with a .01uf (10nf) cap, and take out the 10k resistor.  Now, let's wire up a 50k pot, so that one outside lug goes to the "free" end of the 10nf cap.  The other outside lug goes to the .1uf (100nf) cap in the midscoop filter, and the pot wiper goes to ground. 

Turn the pot in one direction, and you simultaneously place more resistance between ground and the new 10nf cap, and less resistance between the 100nf cap in the midscoop filter, and ground.  At full rotation, the midscoop operates as per stock, and the added 10nf cap cuts little or no highs.

Turn it the other way, and you reduce the resistance to ground for the 10nf cap, cutting highs, as you increase the resistance to ground for the 100nf cap.  At full rotation, you will have effectively gotten rid of the midscoop, and "rounded off" the highs.

My own experience is that it really doesn't take much more than 2-5k of resistance between ground and the 100nf cap to pretty much get rid of the midscoop, so our suggested 50k pot seems like overkill.  That's true for the mid-lift aspect, but not for the treble-cut aspect.  So, to make the control more useable, place a 5k6-6k8 fixed resistor in parallel with that side of the pot (i.e., between the 100nf cap and ground).  That will make settings from the midpoint of the pot's rotation, to the most midlift position, more distinguishable (i.e., turn it a little way and you can hear the difference).

All of this is subject to "seasoning to taste".  So, you may find the new added 10nf cap takes away too much treble, or maybe not enough.  So feel free to change the cap value.

[brokenstarguitar]

With this layout, can i sub the 2n3904s for 2N222As, BC109Bs, or even AC126s or 2N1309s?

[Mark Hammer]

With attention to varying pinouts for transistor types, I suppose you can, although I can't see it improving the character of the unit.  Keep in mind that Q3-5 are not really expected to provide much gain at all (Q3 is unity), and Q4-5 should probably be matched to some extent, for optimum octaving.  If you simply want it for brash fuzz, and don't really care that much about maximum-octaving, then don't worry about matching.

Note that it will distort even if you don't include the pair of diodes to ground.  I installed a 3-position switch in one I made a while back that selected silicon or germanium diodes, or no diodes.  Diodes vs no diodes made a big difference in level and harshness (diodes = harsher but quieter), but the GE vs SI difference was only one of level (at least to my ears).  If I had it to do all over again, I think I would use a DPDT toggle to simultaneously break the ground connection for the diodes, and enable a 33k-68k fixed resistor (depending on diode choice) in series with the volume pot, to maintain relatively constant volume (or at least non-jarring level changes) between diode/no-diode settings.

[brokenstarguitar]

Im trying to get as close to a PEPPERMINT FUZZ as possible. What do u suggest? I thought the super fuzz was the closest but learning all this im not so positive now.

[digi2t]

With this layout, can i sub the 2n3904s for 2n222as, bc109b, or even ac126s?

The Poindexter layout that Mark pointed to will accept any EBC pinout transistor. You could use ECB pinout as well, although that would require some leg twisting. Insofar as your own personal choice of transistor that you decide to use, I recommend breadboarding the circuit first, or at the very least using sockets on the board, to test different transistors. Low gain silicon tend to work best, so 2N2222's would be a good choice. The original transistor was mainly the 2SC828Q, with a gain of 130 to 260. I found that staying below 175 generally yields a more ear pleasing result, but YMMV.

BTW, AC126, besides being germanium, is also PNP, and would not work here.

EDIT:

Im trying to get as close to a PEPPERMINT FUZZ as possible. What do u suggest? I thought the super fuzz was the closest but learning all this im not so positive now.

If I'm not mistaken, the Peppermint Fuzz is based on (if not a copy of) the WEM/Rush Pepbox fuzz. Silicon (NPN), and germanium (PNP) versions of this circuit can be found on the net.

[brokenstarguitar]

With this layout, can i sub the 2n3904s for 2n222as, bc109b, or even ac126s?

The Poindexter layout that Mark pointed to will accept any EBC pinout transistor. You could use ECB pinout as well, although that would require some leg twisting. Insofar as your own personal choice of transistor that you decide to use, I recommend breadboarding the circuit first, or at the very least using sockets on the board, to test different transistors. Low gain silicon tend to work best, so 2N2222's would be a good choice. The original transistor was mainly the 2SC828Q, with a gain of 130 to 260. I found that staying below 175 generally yields a more ear pleasing result, but YMMV.

BTW, AC126, besides being germanium, is also PNP, and would not work here.

EDIT:

Im trying to get as close to a PEPPERMINT FUZZ as possible. What do u suggest? I thought the super fuzz was the closest but learning all this im not so positive now.

If I'm not mistaken, the Peppermint Fuzz is based on (if not a copy of) the WEM/Rush Pepbox fuzz. Silicon (NPN), and germanium (PNP) versions of this circuit can be found on the net.

Ive also read the Peppermint fuzz is  based on the Wem Rush Pep box but while looking into it i cant find the ACYs. Could i use  one of the previous mentioned nd how would i add that tone pot to this pep box? Im going to breadboard the pep box since thats what keeps coming up when researching the Peppermint the. I just gotta find suitable substitutes for the Trannies.

[digi2t]

Insofar as the germanium version is concerned, I think that any pair suitable for a fuzz face would probably work fine here. ACY41's are listed as hfe 50 minimum, so say between 50 to 150 puts you into FF territory, so there's all kinds of different (read "readily available") transistors out there to sub with, especially cheap Russian models. Maybe 2N130x would be good here as well?

I just took a listen to the Ghost Effects silicon version (BC107), and it sounds pretty cool.

EDIT;
Just checked out the other forum, and there is a thread there on the Peppermint fuzz, listing the parts, and transistor gain. Looks like the transistors used are higher gain than a fuzz face, though how the gains were measured is unknown. Sockets are your friends.

[brokenstarguitar]

The other forum?

[digi2t]

The other forum?

freestomp

[smallbearelec]

Im trying to get as close to a PEPPERMINT FUZZ as possible.

I'm the guy who answered your initial question about the ACY41. I got curious, so did a little fishing based on the other posts in this thread.

According to the posts on freestompboxes, M. Piera's Peppermint Fuzz is a modded Fuzz Face. Get out your breadboard, buy a tested Germanium FF pair (or create your own) and a few inexpensive silicon devices, then start learning to tweak and bias.

http://diy.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

Re the Superfuzz, WEM Pepbox and the FZ-1/1A, all of which have been mentioned here: They are interesting pedals, but they are all different, and none is similar to the FF.

If you do experiment with the germanium FF, don't worry about getting particular part numbers. The relative gains and leakages are Much more important.

http://diy.smallbearelec.com/HowTos/FuzzFaceFAQ/FFFAQ.htm

Also some beginner notes:

http://diy.smallbearelec.com/HowTos/BeginnerArticle/BeginnerDos.htm

Happy Construction in 2015!

SD