Happy Fuzz Friday everyone! You probably didn't miss this collaboration between Josh Scott and Mike Matthews, and because of the old school style of the big box version, it wasn't to hard to trace. There's still a few things we don't know about the circuit, so have your sockets handy if you put this together (see notes below). There's some debate over the touted originality of the circuit, as it appears to be a Bazz Fuss into a Tim Escobedo PushMe PullYou, but do your best and leave that discussion to the forums. FSB trace thread for reference.
Notes:
- Q1 is a large can (TO-39 by the looks of it) transistor. I doubt it's germanium, so I assume it's something relatively low hFE like a 2N1711. I'd try out 2N2222A, 2N3904, 2N5550 and see what works/sounds best. The transistor types listed in the layout are an assumption based on the PushMe PullYou.
- D1 appears to be old stock of some sort, with orange and green color bands. I would assume a 1N4148 will work just fine here like in a typical Bazz Fuss.
- C1 is a small ceramic cap, value unknown. I'd start experimenting with anything between 100-470p.
- The 10uF cap off lug 2 of the Balance pot is an assumption based on the PushMe PullYou. It could be as large as 100uF as it's the same size axial capacitor in the original as the power filter caps.
I can verify the layout. Mine has a 2n3904 at Q3. I socketed Q1, C1, D1, and the 10 uf.
ReplyDeletewith a 2n222a at Q1, a 1n34a and a 220pf it sounds and works great! ( each pot does what it should) I get different sounds swapping parts some good some meh. I left it at 10uf alone.
It's a good one.
Awesome. Thanks for verifying!
DeleteCleans up nicely with guitar volume control. As previous OP it works as intended however i will be experimenting with other components.
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ReplyDeleteHere new info: https://www.freestompboxes.org/viewtopic.php?t=32602&start=80&fbclid=IwAR1Cy2pkCv7Npd9C9Upzy4xnniFUh-98ohjAnP-G3YCjF9Be8W9bClHgGMM
ReplyDeleteThe shunt feedback with a diode in Hemmo's BazzFuss circuit is pre-dated by Bob Myer's 1969 muff, so we can say EHX used their own IP... but Myer's design is again, pre-dated by Ethan Winer's Fuzztone... the Tim Escobedo part, i dont know.
ReplyDeleteThe shunt feedback with a diode .... just rectifiring signal. What we have in the end? Square output signal, very close to it! Fuzz lost wide tune range.
Deleteso, today i had some time to play with it! I heard a lot of people was upset, got this fuzz. Yes, scheme is not perfect, i didnt like it too, but i made better. 1. Take Q1 germanium npn like mp38a. 2. Put off that rectifier diode from base & collector of the Q1! 3. Tune resistor in the collector Q1. 4. - Be happy, Happy fuzzes! You got really nice fuzzmachine, all pots working right!
ReplyDeleteor if you dont have germanium, do the same but add resistor 600 - 800k from base Q1 to +
ReplyDeleteI've built two so far. In both instances, I found that using a Germanium PNP for Q4 got me a pleasing sound (inspired by a Youtube video of someone's build of the Escobedo Pushmepullyou, with a footswitch for selecting between Ge and Si). I found it important to have the hfe of Q3 and Q4 within talking distance of each other, although they don't HAVE to be identical. Remember that the Octave control can be used to adjust their matching. I went from using a 2N5088 for Q1 (hfe>500) to a somewhat lower gain BC547 (hfe around 350). That got me a pleasingly wide range of tones. What has impressed me most is how lowering the guitar volume a bit gets one an entirely different "family" of drive tones, more on the crunchy rhythm side, with more tonal contrast between neck and bridge pickups. Turn the volume up and it gets delightfully woolly again, on both pickups
ReplyDeleteThe octaving is nowhere near the quality and robustness of, say, a Foxx Tone Machine, or PEI Clean/Octave Boost, but more robust than a Univox Superfuzz and several other octave fuzzes I've built.
Try Q1 npn germanium without diode! The octaving is nowhere near the quality and robustness of, say, a Foxx Tone Machine - Yes, this more like Phase shifting like Fuzzrite or Shin Ei FY 2, Merkin fuzz
DeleteAs it turns out, the output of Q1 - the "bazz fuss" stage - makes a decent fuzz on its own. I was poking around with an audio probe last night, and found it sounded pretty damn fine. Obviously not able to deliver any octaving, though. So a suggestion to would-be builders: install a DPDT toggle or slide switch between the output of that first transistor stage and the input of the volume control, to select between two different fuzzes. Note that the output of the last transistor pair will be hotter than Q1, though Q1's output is hot enough to be its own pedal. Note as well, that you will want to have one of the 100nf caps between Q1 and the volume control in circuit. That could be *either* the one between Q1 and Q2, OR the one just before the Volume pot. Your choice. One's as good as the other, although there would be a bit of switch popping when going back and forth.
ReplyDeleteAfter some thought and testing, what you want as the branching point is the output of Q2, and not Q1. It still gets you the bazz fuss sound, without octaving, but gets you a hotter signal that us a better volume match to the entire circuit, as well as variable gain. Your build may be different, but I find that, when tapping the output directly from Q2's output, turning the Balance control up full gets you a woolier wooly sound than the stock full Lizard Queen achieves, which is nice.
DeleteSo, although use of a standard NPN transistor for Q1 yields a pleasing and very usable sound and range of tones, there was still something missing from the octaving - namely octaving. I removed the BC547 and subbed in an MPSA13 darlington transistor, which is what should have been in there all along. The octave came alive. Every bit as nasty as my Ampeg Scrambler. The only caveat is that there was a huge volume jump that I'll need to attenuate. BUt that's easily done.
ReplyDeleteHello everyone. Just finished this project and Im a little confused. Everything works fine, but i cant get an octave... something like an octave is mixed into the signal but it's not like what I've heard in the reviews. Is it ok? I used 2n2222 as q1&q3 hfe 200, 5089 for q2 hfe 500 and 5087 hfe 300 for q4. Where could I go wrong?
ReplyDeleteI have no octave effect at all. For Q1 I have tried MPSA13, 2N2222A and 2N5555, but those do not change anything. Is there something I am missing, or is there some other component on the board that affects the octave? Please advise.
ReplyDeleteSince you have this done, could it be possible to do a layout of just the push me pull you pedal?
ReplyDeleteIt sounds good, but the octave pot affects very little, until i hit max, there the octave is really present... but with octave in max i get a drastic volume drop/bass cut. any ideas?
ReplyDelete