It´s donne now. Completely ravaged, indeed! For him to learn. Perfect layout. Changed a bit some values (27 nF/18 nF on Tone); 2sk117 on transistors; big mustard caps (from he sixties) in all. Man, it roars as hell. Wilder than the original. Uncivilized as he should! Tag it, mister Fuzzhead! I'll never be able to thank you enought!...
Hey Ian - I don't know how much this might end up costing you with shipping and such, but pedalhacker here in California has a bunch of NOS 2sk184 jfets right now. The specs are pretty close to 2sk117's from what I can tell.
Cheers Chris, that shop certainly has an interesting selection. In the end I added the missing 10uf cap and it sounds much better - no horrible noise although its a real pain tuning in the fets
Hi. You better try to tune the trimmers by ear. Till you find the proper spot. It takes a lot of search. I know, I buil two, one with 2sk117, and the other with J201 (smd with adapter). One thing is for sure: while you're not there, the sound can get very weird and onoxious (or no sound at all). But once you found it is to set and forget. Good luck!
That's the problem with J201: a lot of fakes arround. For the price they are selling it (Banzai), I would'n't put my hands on fire for them. For me, a lot of SKs (117,170...) will do better, cheaper and no danger with fakes. Great lost for mankind Fairchild passing. :O/
built this wee guy used mmbfj201 but man, the squealing is quite intense and sounds very fizzy. after about 11pm on the gain dial just squeals the only way it goes away is when the treble is all the way down
I'm also getting some pretty horrendous squealing with this one. I tried 201s I got from Tayda (thru hole and SMD) as well as some SMDs I got from GuitarPCB. 4.5v on all the drains. These same FETs sound fine in my other builds. anything else that might cause the squealing?
I did actually! noticed it on the PedalPCB schematic. it worked when I just touched the leads to either side of the 1k resistor, but for some reason when I soldered it in it killed the signal. i snipped the positive leg and signal came back and so did the squeal. I'm gonna play around with it some more before I give up. I'll report back if I get it working.
I’ve had that with j201’s. But I love them. It’s worth the struggle to find some that are quieter I feel. The most temperamental stuff always seems to sound the most inspiring. But adapting the smd is rough.
I’ve build it and does Not work, Maybe my j201 are Not legit? There is masive noise. Where i am it’s impossible to find a 2 meg pot, Maybe 1meg works by theway? I’ve check the traces on all the pcb, all Right, all the soldering… That’s difficult to explain without a video.
I actually built this twice a couple years back. I have a small stash of legit j201's. My builds were crazy noisy. I also wasn't impressed with the drive under the cacophony. Never boxed it up, but occasionally I think about digging it out and giving it another try. Also, 2M pots seem to be hard to source everywhere. I seem to remember somewhere someone mentioning that a 1M works fine. Boxing the circuit may tame the noise some. Good luck
You definitely need legit j-fets for this, anything else just creates a ton of noise. I used Soviet КП303А fets and it works fine, just gets a little fizzy with the gain up but I think thats what is supposed to happen. You can get them from diy-tubes.com
Interesting. I would've tried all the FET's that I have, I'm sure. I definitely would've tried 5457's with similar results. I'll have to audition some alternatives. Never understood the hype this circuit receives.
Revisited this one. Tried alternate, appropriate JFET's and had the same results until I found another batch of J201's that I don't remember buying. Worked perfectly. I know these parts can be temperamental but Jesus. So for others having similar problems, try all the parts that you have on hand. Also, Tayda is stocking 2m pots currently. Thanks for the advice Ian. Good sounding circuit.
What?!! Now I'm mad...really mad!! Watch what I'm gonna do with you Benson suff!...
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteIt´s donne now. Completely ravaged, indeed! For him to learn. Perfect layout. Changed a bit some values (27 nF/18 nF on Tone); 2sk117 on transistors; big mustard caps (from he sixties) in all. Man, it roars as hell. Wilder than the original. Uncivilized as he should!
ReplyDeleteTag it, mister Fuzzhead! I'll never be able to thank you enought!...
Great! Tagged. Yes, those SK117 has alot of punch, one of my favorite J FETs.
DeleteWhere do you chaps get your SK117s from, can't seem to find them anywhere
DeleteHey Ian - I don't know how much this might end up costing you with shipping and such, but pedalhacker here in California has a bunch of NOS 2sk184 jfets right now. The specs are pretty close to 2sk117's from what I can tell.
DeleteCheers Chris, that shop certainly has an interesting selection. In the end I added the missing 10uf cap and it sounds much better - no horrible noise although its a real pain tuning in the fets
DeleteJust finished mine, used J201's and the required settings for the trimmers but it sounds really farty :S any suggestions?
ReplyDeleteTried different J201 transistors but it still sounds weird :S help is welcome :)
DeleteHi. You better try to tune the trimmers by ear. Till you find the proper spot. It takes a lot of search. I know, I buil two, one with 2sk117, and the other with J201 (smd with adapter). One thing is for sure: while you're not there, the sound can get very weird and onoxious (or no sound at all). But once you found it is to set and forget. Good luck!
ReplyDeleteThx for your reply! I'll try to tweak it a bit more!
DeleteOkay I tried to tune it by ear and it's much better now! The tweaking is pretty tricky thoughh... thx guys
DeleteBy he way, where did you get your J201s?...
ReplyDelete@banzai music
DeleteFingers crossed that your J201s are legit since the ones I got from Banzai a couple of years ago were fakes.
DeleteHow can I check if they are fakes?
DeleteThe normal J201 I bought were all out of spec, but I got great results with MMBFJ201. Its the smd version of the J201.
DeleteThat's the problem with J201: a lot of fakes arround. For the price they are selling it (Banzai), I would'n't put my hands on fire for them. For me, a lot of SKs (117,170...) will do better, cheaper and no danger with fakes.
ReplyDeleteGreat lost for mankind Fairchild passing. :O/
built this wee guy used mmbfj201 but man, the squealing is quite intense and sounds very fizzy. after about 11pm on the gain dial just squeals the only way it goes away is when the treble is all the way down
ReplyDeleteany ideas?
Q1
d - 5.2v
s - 0.22
g - 0.04
Q2
d - 4v
s - 0.22
g - 0.00
Q3
d - 4.00v
s - 0.17
g - 0.21
i should mention Q1 was biased with the 12k resistor in mind
DeleteDid you solve it? I have the exact same problem
DeleteI'm also getting some pretty horrendous squealing with this one. I tried 201s I got from Tayda (thru hole and SMD) as well as some SMDs I got from GuitarPCB. 4.5v on all the drains. These same FETs sound fine in my other builds. anything else that might cause the squealing?
ReplyDeleteTry to add another 10uF from G13 (+) to K11 (-). It worked with mine. No more squealing.
DeleteI did actually! noticed it on the PedalPCB schematic. it worked when I just touched the leads to either side of the 1k resistor, but for some reason when I soldered it in it killed the signal. i snipped the positive leg and signal came back and so did the squeal. I'm gonna play around with it some more before I give up. I'll report back if I get it working.
DeleteI’ve had that with j201’s. But I love them. It’s worth the struggle to find some that are quieter I feel. The most temperamental stuff always seems to sound the most inspiring. But adapting the smd is rough.
ReplyDeleteInteresting new version just released with q1 replaced by a germanium transistor. Sounds pretty simple. Might be worth a play with.
ReplyDeleteI’ve build it and does Not work, Maybe my j201 are Not legit?
ReplyDeleteThere is masive noise. Where i am it’s impossible to find a 2 meg pot, Maybe 1meg works by theway? I’ve check the traces on all the pcb, all Right, all the soldering… That’s difficult to explain without a video.
I actually built this twice a couple years back. I have a small stash of legit j201's. My builds were crazy noisy. I also wasn't impressed with the drive under the cacophony. Never boxed it up, but occasionally I think about digging it out and giving it another try. Also, 2M pots seem to be hard to source everywhere. I seem to remember somewhere someone mentioning that a 1M works fine. Boxing the circuit may tame the noise some. Good luck
DeleteYou definitely need legit j-fets for this, anything else just creates a ton of noise. I used Soviet КП303А fets and it works fine, just gets a little fizzy with the gain up but I think thats what is supposed to happen. You can get them from diy-tubes.com
DeleteInteresting. I would've tried all the FET's that I have, I'm sure. I definitely would've tried 5457's with similar results. I'll have to audition some alternatives. Never understood the hype this circuit receives.
DeleteRevisited this one. Tried alternate, appropriate JFET's and had the same results until I found another batch of J201's that I don't remember buying. Worked perfectly. I know these parts can be temperamental but Jesus. So for others having similar problems, try all the parts that you have on hand. Also, Tayda is stocking 2m pots currently. Thanks for the advice Ian. Good sounding circuit.
Delete