My Fuzz Flag Won't Unfurl

[frankie5fingers]

So it's gotta be me, right?  I've bought and sold more fuzzes than I can remember.  Recently I've built two FFs, one AC127, one BC108/9, a BazzFuss and a Pastyface with OC76s.  The PF is by far the best of the lot, as good as it gets.  The OC76s are the smoothest germaniums I ever heard and the added mojo of some super NOS caps is stellar, a wide range, no fizz, and (on battery) absolutely noiseless.
Bottom line though, I still can't find a use for it beyond a song or two and some noodling.  This one sounds like a Tonebender should, better in fact than I remember.  I just can't seem to dial down the fuzz to level that'll help it to find a home on the board.  In this case I ordered a set of OC76s at (T) hFE of 68, 70 and 90 for Q 1,2, and 3.  It cleans up really well but not enough to be useful.  I built it to Soulbender spec, the only mod was mounting the bias pot outboard, I tried a couple of variations (THX Jacob!) but wound up using the 500K.  Any suggestions?

[Haberdasher]

I would add a 50kb or 100kb pre-gain pot.

take the input wire from the pcb and send it to lug 1 of a 50kb pot and then send lug 2 to where the input wire would normally connect to the 3pdt.  That reduces the amount of fuzz as the pot is turned CW.  If you want the fuzz to increase as the pot is turned up just move the wire from lug 1 to lug 3.

[frankie5fingers]

That's interesting - I'll try that.  Thanks Keefe!

[JakeFuzz]

Try another NPN germanium fuzz face without AC127's. You could also do an all Si or hybrid FF with a low gainer in the Q1 (hfe~60-70). The gain of Q1 helps the FF clean up if it is low, try a different NPN because most will have much better low end response than AC127's and Si. You could also do a MKII with a big output cap. The FF and the MKII have the best volume roll off overdrives of the fuzzes IMO. The MKII gets a good crunchy drive while the FF goes to more of a cleaner, slightly fuzzy overdrive. None of my fuzzes go to complete clean though. If that is what you are going for then you are going to have to play around with the gains of the FF transistors, I think that is what analogman mike has done with his NKT's to get that super chimey clean when you roll back.

[frankie5fingers]

I've swapped several NPNs in the FF, but haven't really searched for a really low gain Q1.  The AC127s are great, but again won't roll back far enough for my taste, same with a Si/Ge combo of BC108 or 109, or 5889.  I have some others I may swap for trial's sake though.  How about the MKIII circuit Paul - same idea - super low in Q1?  I liked Keefe's gain pot solution.  I'll try that when I get home from work today and see how that goes.  Like I said, I really do like to overall tone of the Pface, I just can't clean it up enough to kick another pedal off the board.

[Haberdasher]

I've heard the pre gain works pretty well on a TB so it's worth a try.  Easy enough to undo it if you don't think it's working.

I think it really may not be much different than the volume knob on your guitar, but when you roll your axe down you're rolling it down for everything else in your chain too.  This way you have that control dedicated to the TB, so you may find that it allows it to co-exist better.  It might get you down in the range you're looking for even if it is using it in conjunction with your guitar's volume.

[JakeFuzz]

I've swapped several NPNs in the FF, but haven't really searched for a really low gain Q1.  The AC127s are great, but again won't roll back far enough for my taste, same with a Si/Ge combo of BC108 or 109, or 5889.  I have some others I may swap for trial's sake though.  How about the MKIII circuit Paul - same idea - super low in Q1?  I liked Keefe's gain pot solution.  I'll try that when I get home from work today and see how that goes.  Like I said, I really do like to overall tone of the Pface, I just can't clean it up enough to kick another pedal off the board.

Not so much with the MKIII I have. I have put a really low gain ~40-50 in Q1 and it still doesn't clean up well. AC127's are great transistors but the ones I have tried do fall on the bright side, I like them a lot for Q2. There are some really low gain Si npn's out there. Try the 2N2369 from SB, there are quite a few others. Tayda has a few too; I think I just browsed through the datasheets until I found the average gains. Yes Keefe's suggestion is very good. I use this same control when I run my fuzz into my tube pre-amp to control the gain. I still haven't gotten my PF to clean up well at all; in fact the volume knob does very little until it's off.

[frankie5fingers]

I'll try that.  The pre-gain sounds like a great plan no matter what; I like the idea of using the knob at the pedal as a guitar volume for just that one pedal.  I ordered them from "Bartlett on Heath Meadowswitch" (or something like that) in GB.  Mr. Nigel St. Faversham-Smythe did right by me in finding gains and matching the OC76s to 70, 70 and 90 hFE.  At $45 the set, I'm not going to order another lower gain trio though.
FWIW, I also asked if I could match and specify gain for the OC81D reproductions on the Mammoth site but never got a reply so that may be an option too, dunno.
Anyhow, I'll try the pregain pot and see what's what.  As always, thanks much for the guidance.  Frank

[frankie5fingers]

Added the 50kB pot, per Keefe's suggestion.  It's really a very nice added piece of flexibility; I highly recommend it.  It rolls back the fuzz as my guitar volume would and offers up a far more distinct tone, especially in the more trebley area of the tone control.  It comes on/off pretty quickly with the 50k pot, but I really think I'm splitting hairs to swap it for a 100k.  It's enough to make the PF useable for quite a few things.  I also soldered (vs sockets) the three OC76s and that too made quite a difference.  I guess a leg or two wasn't in the socket solidly enough.  Those long legs are pretty spindley.  Overall tone is greatly improved and with the addition of the added flexibility of the pot has found the fuzz a place on the board.  Once again, Keefe and Paul, I appreciate the advice.
As for the FF, I'll keep trying different trannies but I don't hold out much hope for that one.  At last count I tried AC127, BC108 and 109, 2n5888/9, BC549, 2n3904, 2n2222, 2n3565 and a couple of others as well.

Edited for new developments