Only thing I caught just glancing at the schematic is that the 3.3k off Fuzz 1 should be 2k2, although it probably won't make any audible difference. Everything else looks good. Will build later today and report back.
Wow thanks Anders, you are a machine! The only other difference I spotted aside from the resistor that Brain mentioned, is that output should be on level 2. I will plan to build after work. Thanks again.
what transistors did you use? I'm having all kinds of issues with mine, and I've ruled out a build error. Thinking it might be severely out of spec BJTs.
Oh man... this one is really giving me a headache for some reason. Rather than try to describe the problem I'm having, here's a video (sorry for the crappy audio):
I'm using BC549C transistors, but I don't recall ever having an issue subbing them for the B variants in the past. I got so frustrated with my first build, I scrapped it and built another from scratch, being reeeeeally careful this time. SAME EXACT PROBLEMS. I took a pic and checked it against the layout in photoshop just to make sure nothing was out of place. It's all good. Went through every single point on the board with my DMM to make sure everything is connected as it should be and there were not solder bridges. Everything checked out. Thought maybe it was the transistors, so I tried swapping around other transistors, including the 548s MentholMax mentioned. Still, same problem.
I've built and troubleshooted a bunch of pedals, some from very large and complex layouts, and it figures this tiny circuit is the one giving me all this grief. 'Bout ready to throw in the towel :/
Alright, so believe it or not, I hadn't fully cranked the gain on my build until after hearing yours, but my build is doing the same thing. I will try some lower gain transistors.
I'm having better luck with some 2n2222s. It's still not quite like the demos I've seen, but it's much closer. Although, when the Fuzz knob is dimed, it makes an awful screeching noise. But if I back it off just a hair it goes away. Clamp doesn't seem to be doing much now. Definitely not as big a difference as it had with the 549s. Maybe this circuit is just super picky about the specs of its BJTs?
I’m finding this tricky too. I’m using all original parts and whilst I’m not getting the noise problem you have, when the fuzz is low I’m getting a strange swell into the notes. Never heard that in a fuzz pedal before.
This is a quote from PPCB forum for the same build. "I found this circuit to be very picky about transistor and hFe/gain, especially Q1/left and Q2/center: I first tried few BC183C, BC239C, BC550, or other high gain I usually use in BM and such, and I had a hard time making this circuit to work with these (with fuzz all the way up, I had no sound coming out of the pedal, like the transistor gain was too high and was choking the circuit). Then I found some old BC107A and BC107B and finally with those I got a wonderful sounding fuzz! Q3/right on the other hand seams to be the easy spot: there also a MPSA18 was working very well. In then end there I put a BC109C."
Second that! Built with some BC548's haven't listened to the demos but she sounds good to my ears. Thanks for all the continuous content, highlight of my day is seeing something new on the feed! It's greatly appreciated!
lol! Ok, I'll whip up a layout for that green mid honk OD. The Maxon version is pretty much identical except for the buffers being op amp based while the TS9/808 have transistor buffers...
There's the Maxon OD-88. I personally don't like screamers. I did build a God City Instruments Hannibal which is a screamer with a baxandall stack. It's nice. I built it from a GCI board some while back but I think there's a strip version on dirtbox.
Thanks for the tips zzoyd! I've got some BJT's that should be arriving soon, and I want to see if I can get the circuit working with the intended gating effect. But I will probably also make a second build and muck around with the bias resistors.
Hey gyus! Sorry for being quiet lately. Been on vacation and when I got back I got that pesky Covid virus....again....X-(.
Yes, 1,2M at the collector at Q3 makes no sense. It looks like a simple BJT booster/recovery stage so 10k would be a normal value. Pretty certain that the schematic has a typo in that spot. I guess we need to wait for the full build doc being uploaded...:-/
The PedalPCB schematic had a typo for the collector resistor at Q3, indeed. Fuzzdog have the correct value in their schematic, 1,2M should be 12k which totally makes sense. The layout is updated.
Only thing I caught just glancing at the schematic is that the 3.3k off Fuzz 1 should be 2k2, although it probably won't make any audible difference. Everything else looks good. Will build later today and report back.
ReplyDeleteWow thanks Anders, you are a machine! The only other difference I spotted aside from the resistor that Brain mentioned, is that output should be on level 2. I will plan to build after work. Thanks again.
ReplyDeleteYou can tag this one. It sounds like the demos. Thanks for all the layouts!
ReplyDeletewhat transistors did you use? I'm having all kinds of issues with mine, and I've ruled out a build error. Thinking it might be severely out of spec BJTs.
DeleteI used BC549B. I built it as pictured, apart from the 3.3k > 2.2k resistor change and output connection. What kind of issues are you having?
DeleteThanks for verifying this one as well! Tagged.
DeleteOh man... this one is really giving me a headache for some reason. Rather than try to describe the problem I'm having, here's a video (sorry for the crappy audio):
Deletehttps://drive.google.com/file/d/1sn_zZJXAoHexo23_F1Hv54aL51XgsLXn/view?usp=sharing
I'm using BC549C transistors, but I don't recall ever having an issue subbing them for the B variants in the past. I got so frustrated with my first build, I scrapped it and built another from scratch, being reeeeeally careful this time. SAME EXACT PROBLEMS. I took a pic and checked it against the layout in photoshop just to make sure nothing was out of place. It's all good. Went through every single point on the board with my DMM to make sure everything is connected as it should be and there were not solder bridges. Everything checked out. Thought maybe it was the transistors, so I tried swapping around other transistors, including the 548s MentholMax mentioned. Still, same problem.
I've built and troubleshooted a bunch of pedals, some from very large and complex layouts, and it figures this tiny circuit is the one giving me all this grief. 'Bout ready to throw in the towel :/
Alright, so believe it or not, I hadn't fully cranked the gain on my build until after hearing yours, but my build is doing the same thing. I will try some lower gain transistors.
DeleteI'm having better luck with some 2n2222s. It's still not quite like the demos I've seen, but it's much closer. Although, when the Fuzz knob is dimed, it makes an awful screeching noise. But if I back it off just a hair it goes away. Clamp doesn't seem to be doing much now. Definitely not as big a difference as it had with the 549s. Maybe this circuit is just super picky about the specs of its BJTs?
DeleteI’m finding this tricky too. I’m using all original parts and whilst I’m not getting the noise problem you have, when the fuzz is low I’m getting a strange swell into the notes. Never heard that in a fuzz pedal before.
DeleteThis is a quote from PPCB forum for the same build. "I found this circuit to be very picky about transistor and hFe/gain, especially Q1/left and Q2/center: I first tried few BC183C, BC239C, BC550, or other high gain I usually use in BM and such, and I had a hard time making this circuit to work with these (with fuzz all the way up, I had no sound coming out of the pedal, like the transistor gain was too high and was choking the circuit). Then I found some old BC107A and BC107B and finally with those I got a wonderful sounding fuzz!
DeleteQ3/right on the other hand seams to be the easy spot: there also a MPSA18 was working very well. In then end there I put a BC109C."
Second that! Built with some BC548's haven't listened to the demos but she sounds good to my ears. Thanks for all the continuous content, highlight of my day is seeing something new on the feed! It's greatly appreciated!
ReplyDeleteAnders - can I address the elephant in the room here...(😉)
ReplyDeleteCan we please have a straight up old style ts9/808 please 🙏
I think you might have to wait for Anders to regain consciousness after reading that comment 🤣.
Delete????
DeleteJust my weird sense of humour 😉.
DeleteI wonder if there's a reason why???🤔
Deletelol!
DeleteOk, I'll whip up a layout for that green mid honk OD.
The Maxon version is pretty much identical except for the buffers being op amp based while the TS9/808 have transistor buffers...
That's what threw me! I wasn't expecting to see two opamps!
DeleteThank you 😊☺️
There's the Maxon OD-88. I personally don't like screamers. I did build a God City Instruments Hannibal which is a screamer with a baxandall stack. It's nice. I built it from a GCI board some while back but I think there's a strip version on dirtbox.
ReplyDeleteMaxon OD-808
ReplyDeleteGood call. Thank you...I looked at the maxons, but did think it was quite the thing because of having 2 chips...but I'll try it. 👍
Deletestrange resistor 1m2 in collector Q3...too much!
ReplyDeleteIf you want to make work this fuzz,
ReplyDelete1. change resistor 1m2 in collector Q3 on 10-47k!
2. tune resistor bias in collector Q2! No gate!
3. Happy Fuzzes!
Thanks for the tips zzoyd! I've got some BJT's that should be arriving soon, and I want to see if I can get the circuit working with the intended gating effect. But I will probably also make a second build and muck around with the bias resistors.
Deletetried this but got crazy hiss and noise when Q2 & Q3 are biased to 4.5-5v. no way to get rid of the noise without killing the signal :/
DeleteHey gyus!
ReplyDeleteSorry for being quiet lately. Been on vacation and when I got back I got that pesky Covid virus....again....X-(.
Yes, 1,2M at the collector at Q3 makes no sense. It looks like a simple BJT booster/recovery stage so 10k would be a normal value. Pretty certain that the schematic has a typo in that spot. I guess we need to wait for the full build doc being uploaded...:-/
That virus has been running amok! Some people have been pretty ill with it too!
Deletefwiw, i was digging around the PedalPCB forum and saw that someone used a 12k for R8 in their build of this pedal.
DeleteI got very cool sound with Germanium MP38a Q1,Q2. Q3-silicon. Just tune Q2 bias in collector! + added switch to off diodes!
ReplyDeleteThe PedalPCB schematic had a typo for the collector resistor at Q3, indeed. Fuzzdog have the correct value in their schematic, 1,2M should be 12k which totally makes sense. The layout is updated.
ReplyDeleteIt's still appears that the layout isn't updated. The upper 1.2M should be a 12k
ReplyDeleteNow it is...
DeleteThis is a badass fuzz. Thanks for following up on it.
ReplyDelete