Univox Superfuzz - Transistors

[FastJunkie]

I'm building a Superfuzz based on the schematicheaven diagram (http://www.schematicheaven.com/effects/univox_superfuzz.pdf) and I see it calls for 2SC539 and 2SC828 transistors. I believe these are obsolete and I don't really want to order anything so what could I substitute for transistors that would be a more common "2N" type alternative? I think the diodes might also be an uncommon model so any alternatives for those would be great too!

[R.G.]

The superfuzz is remarkably tolerant of different NPN transistors. When it was built, the transistors used were probably chosen for being cheap and available, not magical qualities.

I've built these out of any transistors at hand, with good results.

You can follow Keen's Second Law - when in doubt, whip in a 2N5088.
Or a 2N3904. Or a 2N4124. Or a ...

Like in all transistor subs you simply must get the datasheet for the transistor you actually use, and get the right pins on the transistor connected to the right places on the circuit, or you'll get to post back here with "My superfuzz isn't working..."

[Mark Hammer]

I can't speak for the 539s but 828s are most definitely available these days.  Neither is particularly remarkable, and as RG notes, the Superfuzz does not require anything particularly remarkable.  Certainly aim for something with an hfe >200 or so, but that's really all you need.

[FastJunkie]

So I could use 2N5088's in replacement of both the 2SC828 and 2SC539? Also what about the DA-90, common diode?

[R.G.]

So I could use 2N5088's in replacement of both the 2SC828 and 2SC539?

I would. In fact, I have!  Also the 2N3904s.

Also what about the DA-90, common diode?

It's worth trying. I think the original diodes were germanium, so the sound may be different. But try it. You won't hurt anything. If it works and you like it, you're in. If it's less than satisfying, find some germanium diodes to try.

[mac]

i wonder if q4 and q5 should be matched...  

mac

[isildur100]

For the diodes, I would recommend 1n34 or 1n60 germanium diodes. I have tried with 1n4148, 1n4001 and 1n914 and the only decent sound was with the germaniums. For the transistors, although everyone seems to not having found any difference using different kinds, I do not completely agree. I have tried several kinds and there was a difference in the sound maybe subtle but they were different. I suggest you try for yourself with different ones and see which one suits your needs best. Just my humble opinion. 

[FastJunkie]

For the diodes, I would recommend 1n34 or 1n60 germanium diodes. I have tried with 1n4148, 1n4001 and 1n914 and the only decent sound was with the germaniums. For the transistors, although everyone seems to not having found any difference using different kinds, I do not completely agree. I have tried several kinds and there was a difference in the sound maybe subtle but they were different. I suggest you try for yourself with different ones and see which one suits your needs best. Just my humble opinion.  

I'll have to double check tomorrow but I saw some glass/crystal diodes I thought might be germanium  in the supply room today in an unamarked box with other assorted parts today and I'm pretty sure they were 1n34's. They had gold leads too. Gonna keep my fingers crossed!  

[yeeshkul]

i wonder if q4 and q5 should be matched...  

mac

I'd say yes. Those two create the octave-up effect by flipping one half of the signal swing over. I feel (not sure) that the more equal are the swings, the more prominent the oct-up effect will be.

[yeeshkul]

They sell OD-91 at Banzai.com and they sound more then fine. I believe, there will be almost no difference between those and some other Ge diodes. The main difference is being made by the voltage drop across them, that's why Si sound probably louder and harsher.

[RDV]

I really like mine with metal can 2N2222.

Sounds.

RDV

[jawknee]

I just built my first pedal, a BYOC Leeds Superfuzz clone and don't really love the tone. It's way too scooped and buzzy for me. Also, I don't get much octave effect out of it, but that's okay by me.

I was wondering if anyone here had ever put some germanium transistors in one of these. I am tempted to try replacing the 6 transistors with 2 sets of germanium PNP TB matched sets of 3 from Small Bear. I love the sound of the Mk2 Tonebender and would really like to see if that would change the buzz to more of a fuzz (I hope you know what I mean). I think a hybrid of these 2 pedals would sound pretty cool.

I like the tone switch, but I'd also like to get rid of that scooped sound so it goes from mid/highs, to full on Big Muff-type sound (I know that's a scooped sound too, but seems much less so IMO). Would getting rid of the mid-scoop involve altering the circuit too much or can I get lucky and just swap out some resistors?

[smallbearelec]

ed to try replacing the 6 transistors with 2 sets of germanium PNP TB matched sets of 3 from Small Bear.

While I like selling germanium devices, I don't recommend this. Germanium biases differently from silicon, and TB MKII sets would not be appropriate. Other people may be able to suggest mods to the tone stack that would make you happier. If you go that route, breadboard!

Regards
SD

[jawknee]

So there's no hope for putting a germanium transistor in there? If all the silicon transistors are out of there, why would it matter that the two types (silicon and germanium) bias differently? Is the bias determined by the circuit?

I apologize in advance if that's a stupid question, I just got bit with this pedal making bug and still have a lot to learn.

[yeeshkul]

You can use Ge wherever you want, but don't forget that they have a lot lower Hfe than Si trannies and they leak a lot  - so they do bias differently to what is bias supposed to be here. You will have to adjust some parts of the circuit to get it sound right. If you wanna start fiddling with Ge trannies this circuit is probably not the best to start with to get a quick and nice result. The circuit sounds brilliant with Si trannies anyway.

[RicoRokkaRolla]

What would you recommend guys, OA1182 or 1N34?

[RicoRokkaRolla]

Oh, transistors, but somebody mentioned diodes. So, BC183 and SC3953 would be ok?