Looks like the pedalpcb build doc has some pretty specific stats for the 3 jfets. Anyone wanting to recreate this effect exactly should probably pick up (if you don't all ready have one) a peak semiconductor tester - the numbers in the build doc are listed in the exact format that is on that meter's display screen.
Yeah, I saw that. I plan on approaching the problem with sticking a bunch of random stuff in there and hoping for the best. I’m very scientific in my approach.
My ham-fisted approach got the circuit working but probably not optimally. After rewatching a couple demos, I don’t think I’m getting the level of bass and fuzz that I should yet. But yeah that third gain stage is probably least important.
Verified. Sounds good. I'm getting plenty of gain and everything is working. I guess I shouldn't be surprised that it sounds quite similar to the Smallsound/Bigsound mini. I'll have to do some fine tuning still but the layout definitely works. Thanks for the tidy and compact layout, as always.
I just played this thing through my actual amp without changing anything and gobdangit this thing rips. So it seems to be fairly stable and achievable without much effort, unless I just got lucky, (I'm not especially lucky). It also allows the character of your guitar to come through unmolested somehow without compromising anything. Great fuzz pedal. Love Fairfield. Thanks again Anders.
Thanks a lot!!! Seems a lot like the Smallsound Mini so i`ll stick with the one i have... Maybe at some point you could do the T. Jauernig Bombastortion that has come up on pedalpcb..I really like Jeff Kollman's sound!! Cheers!!!
I started building pedals at the beginning of this year. I've gotten a few successful builds completed but I'm still learning and this one's got me stumped!
For the following, assume the Input, Fuzz, and Volume knobs are all set to ~1 o'clock. For the Bias knob, I used a B100K pot with a 100K resistor soldered to pins 1 and 3 to knock it down to 50K.
The problem I'm having is a very present oscillation within the first bit of the turn on the Bias knob. The areas outside that part of the rotation seem to be unaffected. I'll try to describe the behavior as best as I can below: • With the Bias set fully counterclockwise (~7 o'clock), there is no oscillation, regardless of the other knob settings. • With the Bias set to around 8 o'clock, I'm getting oscillation with a decent amount of low end information (scattered, from around 200Hz up to 10kHz). • With the Bias set from around 9 to 10 o'clock, I'm getting oscillation at only about 4kHz to 6kHz. This is dependent on the other knob settings but the oscillation frequency is primarily affected by Input knob or the guitar's volume level. • With the Bias set from ~10 o'clock through fully clockwise, there is no oscillation, regardless of the other knob settings. • The oscillation is heard somewhat less while playing the guitar but is very present when not playing.
This behavior is making me feel like I'm almost there but missing a critical something. I think it's worth noting that the circuit is currently outside of an enclosure and wired to a tester running off a CIOKS DC7 for power. While I do hear the usual hum of the electromagnetic stuff around it (computer, display monitors, etc.), this oscillation feels like something else is going on.
I am leaning toward the J201s not being matched and making the Bias unhappy? But before I start down that path, I figured I would ask the community in hopes of nailing this one down.
PS - Thanks so much to everyone for everything you've taught me so far. Picking this up has been such a joy.
It could be a number of things but more than likely it's the JFET's. If you don't have something like a Peak you can still take some basic measurements while the J201 is in the circuit. Or simply try some different FET's. Some may not work at all and others may sound noisy and terrible.
It could be the j201s (especially if you got them somewhere not so reputable), however I should point out that that 50k is acting more like a reverse log than a linear, so the sweep is doing almost all the bias choice within the first bits of the turn. Might be that....
Next time I submit a part order at one of the more legit vendors I'll pick up a handful of J201s. In the meantime, I'll shuffle around the ones I've got on hand and maybe experiment with some different pots and see how it goes.
The circuit sounds really nice when it's not on a sea bird insane-o setting so I'm happy to work around that if this is as good as it'll get.
Wow, that was quick. Layout checks out. I'll work on it later today. Thanks brutha.
ReplyDeleteLooks like the pedalpcb build doc has some pretty specific stats for the 3 jfets. Anyone wanting to recreate this effect exactly should probably pick up (if you don't all ready have one) a peak semiconductor tester - the numbers in the build doc are listed in the exact format that is on that meter's display screen.
ReplyDeleteYeah, I saw that. I plan on approaching the problem with sticking a bunch of random stuff in there and hoping for the best. I’m very scientific in my approach.
DeleteI bet in reality the difference is negligible. One of the jfets is operated by a bias voltage knob anyway!
DeleteMy ham-fisted approach got the circuit working but probably not optimally. After rewatching a couple demos, I don’t think I’m getting the level of bass and fuzz that I should yet. But yeah that third gain stage is probably least important.
DeleteVerified. Sounds good. I'm getting plenty of gain and everything is working. I guess I shouldn't be surprised that it sounds quite similar to the Smallsound/Bigsound mini. I'll have to do some fine tuning still but the layout definitely works. Thanks for the tidy and compact layout, as always.
ReplyDeleteThat's awesome Tom. And fast...:-D
DeleteTagged.
I just played this thing through my actual amp without changing anything and gobdangit this thing rips. So it seems to be fairly stable and achievable without much effort, unless I just got lucky, (I'm not especially lucky). It also allows the character of your guitar to come through unmolested somehow without compromising anything. Great fuzz pedal. Love Fairfield. Thanks again Anders.
DeleteThanks a lot!!! Seems a lot like the Smallsound Mini so i`ll stick with the one i have... Maybe at some point you could do the T. Jauernig Bombastortion that has come up on pedalpcb..I really like Jeff Kollman's sound!! Cheers!!!
ReplyDeleteI've built two, just put in whatever j201s I had to hand. Sounds fine to me and matched the YouTube demos pretty well.
ReplyDeleteHey all,
ReplyDeleteI started building pedals at the beginning of this year. I've gotten a few successful builds completed but I'm still learning and this one's got me stumped!
For the following, assume the Input, Fuzz, and Volume knobs are all set to ~1 o'clock.
For the Bias knob, I used a B100K pot with a 100K resistor soldered to pins 1 and 3 to knock it down to 50K.
The problem I'm having is a very present oscillation within the first bit of the turn on the Bias knob. The areas outside that part of the rotation seem to be unaffected. I'll try to describe the behavior as best as I can below:
• With the Bias set fully counterclockwise (~7 o'clock), there is no oscillation, regardless of the other knob settings.
• With the Bias set to around 8 o'clock, I'm getting oscillation with a decent amount of low end information (scattered, from around 200Hz up to 10kHz).
• With the Bias set from around 9 to 10 o'clock, I'm getting oscillation at only about 4kHz to 6kHz. This is dependent on the other knob settings but the oscillation frequency is primarily affected by Input knob or the guitar's volume level.
• With the Bias set from ~10 o'clock through fully clockwise, there is no oscillation, regardless of the other knob settings.
• The oscillation is heard somewhat less while playing the guitar but is very present when not playing.
This behavior is making me feel like I'm almost there but missing a critical something. I think it's worth noting that the circuit is currently outside of an enclosure and wired to a tester running off a CIOKS DC7 for power. While I do hear the usual hum of the electromagnetic stuff around it (computer, display monitors, etc.), this oscillation feels like something else is going on.
I am leaning toward the J201s not being matched and making the Bias unhappy? But before I start down that path, I figured I would ask the community in hopes of nailing this one down.
PS - Thanks so much to everyone for everything you've taught me so far. Picking this up has been such a joy.
It could be a number of things but more than likely it's the JFET's. If you don't have something like a Peak you can still take some basic measurements while the J201 is in the circuit. Or simply try some different FET's. Some may not work at all and others may sound noisy and terrible.
DeleteIt could be the j201s (especially if you got them somewhere not so reputable), however I should point out that that 50k is acting more like a reverse log than a linear, so the sweep is doing almost all the bias choice within the first bits of the turn. Might be that....
DeleteThanks a lot for your responses guys.
DeleteNext time I submit a part order at one of the more legit vendors I'll pick up a handful of J201s. In the meantime, I'll shuffle around the ones I've got on hand and maybe experiment with some different pots and see how it goes.
The circuit sounds really nice when it's not on a sea bird insane-o setting so I'm happy to work around that if this is as good as it'll get.
Really appreciate the help, be well :)
FWIW I use these a lot.
Deletehttps://a.co/d/1p8tBVm
I've never had a problem.
I used smd j201s in the pcb for this pedal and it sounded way off. I took them out and put some of the Amazon ones in with sockets. Works great.