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Pastyface PNP transistors

Started by teknoman2, August 01, 2012, 11:48:53 AM

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teknoman2

I am going to make the Pastyface fuzz pedal

and specifically the "soulbender".

What type of germanium PNP transistors should I use?

I search on Small Bear Electronics and I found various sets of PNP transistors.

I don't know which one is the best for me.

Thanx in advance.


teknoman2


mgwhit

I'd stick with the 3-Knob Bender sets, as Small Bear sends you transistors with gains optimized for that circuit and a Germanium diode for your Q3.  I have purchased the 3-Knob Generic set and the Mk II OC75 set and they have very different gains for the three positions.

teknoman2

Which one you think is the best?

I like the fulltone soulbender and the fulltone 69 MKII Pedal sound.

mgwhit

#5
Well, I bought the 3-Knob Bender set for my Pastyface board since that's what it is (a 3-knob MkIII), and the MkII OC75's for a MkII build on a GuitarPCB board.  I breadboarded a MKII with my 3-Knob set and thought it sounded like ass.  I didn't try the OC75's in the MkIII Pastyface circuit.

I can't compare the 3-Knob Generic set to the Continental set as I have only tried the generics.  For the record, though, I think they sound great.

The Fulltone Soul Bender is a 3-Knob MkIII variant that can be built on the Pastyface board and was certainly my favorite of the four specs included in that build document.

The Fulltone '69 is a Fuzz Face variant that uses only two Germanium transistors (compared to three in the Tone Bender variants).  There is a discontinued board called the Zygote (that you can etch yourself or purchase etched from Haberdasher if you want it) that can be used to build it, and Small Bear has several two-transistor Fuzz Face sets.

teknoman2

So you think if I buy those :

http://www.smallbearelec.com/servlet/Detail?no=1181

I will be okay and my sound will be similar to Fulltone Soul bender.


mgwhit

Quote from: Effectsiation on August 01, 2012, 02:39:43 PM
No, he's recommending you pick one of these 2:

http://www.smallbearelec.com/servlet/Detail?no=11
http://www.smallbearelec.com/servlet/Detail?no=1180

Correct.  Unless you know what you're doing, you should use a 3-Knob set on the Pastyface/Soul Bender.  That's what they're specifically matched for.

frankie5fingers

FWIW, I just finished the Pastyface.  I was a bit dis sappointed at first, but It turned out to be pilot error (as usual); my trannies were marked in red with their hFE and I mistook the 6 for the red dot - I mounted it backwards.  Anyway.  I bought three OC76s from England - got them matched with the hFE I wanted - 68, 69, and 90 for Q1, 2, 3.  I know many of the best reproductions use the OC75, which I believe are the Smallbear set.  I was told the 76s were just a little cleaner and more sparkly and dynamic.  I can't say for sure if that's the case, but they are absolutely great.  By far and away, this circuit with these transistors is the most dynamic, best sounding fuzz I ever used.  Again, FWIW, I'm not a big fuzz fan, I've liked very, very few, but this one is worth every effort and expense.  Wherever you get them, the old Mullards sound great and I have to believe those in this circuit (at least the Soulbender version) is a perfect match.  Do yourself a favor and use OC75 or 76 and take the time to use some nice, low tolerance caps.  My final FWIW, when it came to the 100 and 150pf caps, I used Silver Mica vs ceramic - again, I can't compare the two, but this thing is dead quiet on battery power.  Claim no expertise, just my two cents, but I'm still on the Pastyface honeymoon.  Frank

teknoman2

Thanx Frank I will buy the OC75'

Hope they work for me as well....


mgwhit

Keep in mind that frankie5fingers got his OC76s from a different supplier who allowed him to specify gains for each position.  If you order the MkII OC75 set from Small Bear, you will get a set with gains optimized for a MkII -- a different circuit than the Pastyface/MkIII.  I've heard that the MkIII circuit is pretty forgiving in terms of gain buckets, so you might get away with it, but you also might want to contact Steve at Small Bear.  I've heard he's pretty cool about answering these kinds of questions.

frankie5fingers

THX mgwhit, good point.  That's quite true teknoman.  i dunno if SB will let you spec a range for them.  I ordered elsewhere because I did send a note and was advised that they couldn't guarantee an hFE range, but that once I placed the order, they'd do their best to supply what I was looking for.  I'd bet if you sent an Email, he'd offer the same.  I've always been satisfied with their service and follow up.  I'm sure their OC75 set will work well.
In my case, I took the spec from yet another source, Fuzz Central.  Whether or not 70,70, and 90 is right for you or even the pr ferred values, I couldn't say.  I can't offer much advice there (sorry), but maybe one of the more experienced builders or fuzz gurus could advise the best values.  I can say though, that I'm quite happy with them.