This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.
Here's one for my fellow bassists out there. It's a transistor-ized version of the Fender Bassman preamp as modified by DeadAstronaut over on DIYSB. It's laid out for board mounted pots and switch and will fit nicely in a 1590B.
Thanks for this layout. I want to build this but i'm not sure about the pots. In my country (Asia) "A" for Log pots and "B" for Linear pots. is that the same with this layout?
I have a problem with this pedal, the sound arrive fine until the last resistor (680k) but after that resistance the signal are very low. Why can this be happening?
Thank you so much for this layout! I got a question about those two 100k trimpots. How do I adjust them properly? What is the purpose of each of them? Sorry I'm not good enough to figure it out.
They're there to bias the JFETs. Not all JFETs are created equal and while one resistor value may work for one JFET, it might not with another. Trim pots help to dial in the right amount of resistance from the voltage rail. You'll need to adjust them till you get 4.5v on the drain pins of the JFETs then adjust by ear to get them sounding right.
its verified.. sound is good but the level of effect is a bit lower than in bypass mode.. i tried lowering the output resistor but the sound is getting a bit noisy.but but still the effect level doesnt increase.. how can i fixthis
I got the same problem i tried 330k as output resistor the volume is getting better but The whitenoise is getting noticeable. How can i fix the white noise ?
The result is very good, but the output signal is very weak. Will I have to wear a booster? Is it a design flaw? How to increase the output gain of this project?
Hi! I have a problem with this circut. It works, i set the trimpots to ~4,5V, but its getting fuzzy when I play on lower string. It's like sound gets dirtored. I tried to fix this by setting diffrent voltages, but I cant figure it out.
I used J201 for this.
What should I do, to get rid off that fuzzy sound?
gracias Agustin Zanardi (p0mp0) ;)
ReplyDeleteHey, great work on those layouts!! Just a noob question, how do you adjust the bias with the trimpots, just by ear?? Greetings from México :D
ReplyDeleteAdjust them to about 4.5v and then adjust by ear.
DeleteI bought trimmoots with 25 turns (vueltas in spanish) should be fine? How will i regulate them? Sorry for my inexperience.
ReplyDeleteYou'll need to use a multimeter to check the voltage going to the drains of the JFETs. Set the trimmers to give them 4.5v and then adjust by ear.
DeleteThank you very match!!!
Deleteit serves guitar? i dont find bassman pedal for guitar? sugerencies? please help me
ReplyDeleteIt's designed for bass, but would also work on guitar.
DeleteThanks for this layout. I want to build this but i'm not sure about the pots. In my country (Asia) "A" for Log pots and "B" for Linear pots. is that the same with this layout?
ReplyDeleteYep. A=log B=lin
DeleteHi!
ReplyDeleteI have a nerd question, do you know the frequency range? 40hz - 10khz maybe?
Thanks!!!
No idea there, man. That might have been discussed in the DIYSB thread tho. Link is in the description.
DeleteWill there be ok 20k or 25k pots for treble and bass? - just have no source for 22k pots
ReplyDeleteYeah either of those should be fine
Deleteit's popping. Any resitor to cap switch will remove the pop ?
ReplyDeleteTry a 1M resistor from the input to ground.
DeleteWhat fet to use on this project?
ReplyDeleteWould 2sk170 be any good?
2N5457 are what it's laid out for. I believe the 2SK170 has a different pinout, but may work if you twist the pins around. Use sockets.
Deleteif i change transistors for tube Can i use this pcb?
ReplyDeleteif i change transistors for tube. Can i use this pcb?
ReplyDeleteI have a problem with this pedal, the sound arrive fine until the last resistor (680k) but after that resistance the signal are very low. Why can this be happening?
ReplyDeleteTry replacing the 680k with something smaller like 330k
DeleteThank you so much for this layout! I got a question about those two 100k trimpots. How do I adjust them properly? What is the purpose of each of them? Sorry I'm not good enough to figure it out.
ReplyDeleteThey're there to bias the JFETs. Not all JFETs are created equal and while one resistor value may work for one JFET, it might not with another. Trim pots help to dial in the right amount of resistance from the voltage rail. You'll need to adjust them till you get 4.5v on the drain pins of the JFETs then adjust by ear to get them sounding right.
Deleteso drain pins should be at 4.5v above ground, right?
DeleteThank you so much!
Correct. Then adjust till it sounds right if necessary.
DeleteThis comment has been removed by the author.
ReplyDeleteThe output volume is lower than by-pass! Does anyone have the electronic diagram of this project?
DeleteSchematic should be in the link in the description.
DeleteSo, I ordered some 22K pots for this one, but I got 25K delivered. Will this still work with 25K's?
ReplyDeleteYeah, 25k should work just fine.
DeleteThis comment has been removed by the author.
ReplyDeletedo u have a schematic of this
ReplyDeleteits verified.. sound is good but the level of effect is a bit lower than in bypass mode.. i tried lowering the output resistor but the sound is getting a bit noisy.but but still the effect level doesnt increase.. how can i fixthis
ReplyDeleteWhat kind of parts is 2pcs 100k is it pot?
ReplyDeleteThose are trim pots
DeleteI got the same problem i tried 330k as output resistor the volume is getting better but The whitenoise is getting noticeable. How can i fix the white noise ?
DeleteHi good sound but mine got a pulsing sound in background a sort of rhythmic "pop" sound. Cannot fix it. Can u help?
ReplyDeleteGreetings group, very interesting bass sound!!!, someone has the pdf layout???, thanks.
ReplyDeleteGreetings group, someone can provide me pdf layout MXR M81, MXR M80 or similar. Nice sound !!!!!
ReplyDeleteThanks and success👍.
The result is very good, but the output signal is very weak. Will I have to wear a booster? Is it a design flaw? How to increase the output gain of this project?
ReplyDeleteHi!
ReplyDeleteI have a problem with this circut.
It works, i set the trimpots to ~4,5V, but its getting fuzzy when I play on lower string. It's like sound gets dirtored. I tried to fix this by setting diffrent voltages, but I cant figure it out.
I used J201 for this.
What should I do, to get rid off that fuzzy sound?
You might need to adjust the 1k/47uF values coming off the source pin of each JFET. Or it could just be your J201s.
DeleteWorks fine, but the knobs must be slightly open to get sound. Is this normal?
ReplyDeleteIf the treble, mid, or bass pot are off, the volume is very low
Terima kasih untuk layout yang luar biasa ini.
ReplyDeleteTerverifikasi dengan sempurna
Terima kasih
The effect is awese except the whote noise like a fire burning.How can i fix it.
ReplyDeleteThe effect is awese except the whote noise like a fire burning.How can i fix it.
ReplyDeleteNice but the output cap should be 10uF
ReplyDeleteI love the lows...
ReplyDeletevery flexible design... the treble is also good..
Works!
ReplyDeleteAdjusting the trimpots and changing the 680k to 6.2k works for me finding a desirable output
I made a few of these swapping the 680k output resistor with 5k1 and adding a A100k master volume pot after that. Wonderful preamp. :)
ReplyDelete