Univox - Superfuzz [schematic]

[jrod]

Awesome! Looks good! Those sound like cool mods.

[Chugs]

Very nice indeed. Schematic of the implemented mods?

[Gila_Crisis]

here you go

[bigmufffuzzwizz]

To increase output on the Superfuzz, try putting a 10uf in parallel with emitter resistor on the last stage transistor...... going by memory for what I did with my build a few years ago. negative leg goes to ground.

Tried this on one of my BYOC Leed's Fuzz kits, and it did increase the volume output tremendously. The only thing is the circuit doesn't get as over the top fuzzy when the balance knob is maxed. It looks like it'd take this plus putting an extra gain stage to act as an overall volume, allowing the balance knob to be cranked but bringing the volume down a bit!

[Rolbista]

What are the factors determining amount of distortion here? Transistors, diodes, gain pot value? Just finished a clone and while I think it sounds like it should, i would like to have more gain available, something like this: , , at the maximum. Trannies used are all gold leg BC108, diodes are some random germaniums i found, they have "A101" written on them i think. Or maybe I'm expecting too much, maybe the songs I posted have that kind of gain from amp drive too and that's the only way to achieve it? maybe swap the diodes for 1N1418? Yeah.

[Rolbista]

ok, i got it, i plugged 1n1418 and it sounds great, i don't want to play any other pedal so far! but the scooped mode is a little heavy on the ears

[pietro_moog]

do any of you guys know a layout small enough to fit in a 1590B box?

[mictester]

do any of you guys know a layout small enough to fit in a 1590B box?

Only if you're able to etch!

[rhandy gaye]

http://www.takkyparts.com/

the fuzzy master

[LucifersTrip]

i would like to have more gain available, something like this: ,

there is no better place to start than from the actual Superfuzz that was used!

https://www.diystompboxes.com/smfforum/ ... ic=64068.0

[TubeDude22]

What is the function of the 10uf cap in series with a 47k resistor on the emitter of Q2?

[DiscoVlad]

The frequency response at the emitter of Q2 has a peak of about +22dB at 1kHz, changing the value of the 10uF capacitor lets more low frequencies into the feedback path, which results in a bass cut before the rectifier(Q4/Q5) and clipping (Ge Diodes) stages.

I suspect that this and probably the 10uF capacitor on the emitters of Q4/Q5 are what stops the Superfuzz from sounding muddy.

[Gila_Crisis]

http://www.takkyparts.com/

the fuzzy master

I took a look a it, but I think the Honey fuzz it's a superfuzz. this fuzzy master has only 5 transistors, while the honey has 6

[LucifersTrip]

I finally got around to reading this killer thread...Excuse me if I missed it here somewhere, but I was just curious about a couple things I didn't come across that I was surprised wasn't discussed.

1) What would be a typical hfe of a 2SC539 and 2SC828 in an original Superfuzz?
(my guide shows 90-700 for the 2SC539 and 65-700 for the 2SC828, which is a large range)

2) Since there are 2 different transistors (2SC539 for Q1,4,5,6 and 2SC828 for Q2,3) used according to the schematic,
why does it seem everyone is subbing all the same transistors for Q1-Q6?

3) Did anyone try any germanium subs (and re-bias) for any of the transistors?

thanx

[mictester]

I finally got around to reading this killer thread...Excuse me if I missed it here somewhere, but I was just curious about a couple things I didn't come across that I was surprised wasn't discussed.

1) What would be a typical hfe of a 2SC539 and 2SC828 in an original Superfuzz?
(my guide shows 90-700 for the 2SC539 and 65-700 for the 2SC828, which is a large range)

The 539 had a slightly better noise spec. The 828 seemed to be almost any old transistor that came off the line and they couldn't fit into any particular category! In my experience, the circuit works best with high hfe for the first two transistors and lower for the rest. I used BC109Cs for the first two transistors and then a CA3046 for the rest. Sounds really good!

2) Since there are 2 different transistors (2SC539 for Q1,4,5,6 and 2SC828 for Q2,3) used according to the schematic,
why does it seem everyone is subbing all the same transistors for Q1-Q6?

The types aren't too critical, though it helps if the long-tailed pair are matched and the resistors around them are matched too - you get much more octave that way. Almost any silicon transistors will work well in this circuit!

3) Did anyone try any germanium subs (and re-bias) for any of the transistors?

There's no point. It wouldn't sound much different, and it would be quite temperature sensitive. The biggest change you can get is by using silicon instead of germanium diodes for the clipper!

thanx

[LucifersTrip]

I finally got around to reading this killer thread...Excuse me if I missed it here somewhere, but I was just curious about a couple things I didn't come across that I was surprised wasn't discussed.

1) What would be a typical hfe of a 2SC539 and 2SC828 in an original Superfuzz?
(my guide shows 90-700 for the 2SC539 and 65-700 for the 2SC828, which is a large range)

The 539 had a slightly better noise spec. The 828 seemed to be almost any old transistor that came off the line and they couldn't fit into any particular category! In my experience, the circuit works best with high hfe for the first two transistors and lower for the rest. I used BC109Cs for the first two transistors and then a CA3046 for the rest. Sounds really good!

what do consider "high" gain and "lower"? you're really not sure what would be a typical hfe of a 2SC539 and 2SC828 in an original Superfuzz? I'll keep in mind the higher hfe for the first two, though, it'd seem a little odd since Q2 & Q3 are the different transistors in the original...

2) Since there are 2 different transistors (2SC539 for Q1,4,5,6 and 2SC828 for Q2,3) used according to the schematic,
why does it seem everyone is subbing all the same transistors for Q1-Q6?

The types aren't too critical, though it helps if the long-tailed pair are matched and the resistors around them are matched too - you get much more octave that way. Almost any silicon transistors will work well in this circuit!

yes, the trimmer is there for the pair...so you have tried gains of 65 and gains of 700? I'll try various gains, but it'd be cool to know what would get me closest to the original voltages without tweaking resistors. solidhex was cool enough to post the voltages from an original that sounds great.
https://www.diystompboxes.com/smfforum/ ... ic=64068.0

3) Did anyone try any germanium subs (and re-bias) for any of the transistors?

There's no point. It wouldn't sound much different, and it would be quite temperature sensitive. The biggest change you can get is by using silicon instead of germanium diodes for the clipper!

that, I have to admit seems highly unlikely...there's hardly any fuzz I've built over the years that ge didn't make a difference, for better or worse. this one probably would need a load of re-biasing, so it wouldn't be worth the effort for most.

thanx

[LucifersTrip]

after a bunch more searches, it seems that many believe the original transistors would have hfe's in the 150-200 range

[Solidhex]

I've never seen a 2SC828Q above 300hfe. Usually hover around 180...

[KindaFuzzy]

The few I have are around 180-230.

[LucifersTrip]

The few I have are around 180-230.

Just remember that modern transistors of the same number many times have different (usually higher) hfe's than the old ones.

For instance, my new 2N3906's have gains around 200+ and my old, gold legged ones have gains around 100