Fairfield Circuitry - The Barbershop (gut) [traced]
Yea, less bass with 4.7uF at source.
The zener is there to protect the mosfet. Max Vgs is 20V, in the rare case that this would happen, the zener would limit this to whatever value you got. I'm not sure about this but I think you could still use 18V with a 12V zener. As the zener conducts, the voltage drop on the 2M resistor goes up...
In any case, using The Barbershop with a supply higher than 9V is kinda lame. It becomes too clean, and the Sag knob doesn't have the same effect. I don't even think the circuit would clip at any setting if you used an 18V supply.
You could lower the resistor between the two gain stages, right before the drive pot, sending the 2nd stage into saturation much quicker... it becomes a different pedal.
Have fun with your build.
The zener is there to protect the mosfet. Max Vgs is 20V, in the rare case that this would happen, the zener would limit this to whatever value you got. I'm not sure about this but I think you could still use 18V with a 12V zener. As the zener conducts, the voltage drop on the 2M resistor goes up...
In any case, using The Barbershop with a supply higher than 9V is kinda lame. It becomes too clean, and the Sag knob doesn't have the same effect. I don't even think the circuit would clip at any setting if you used an 18V supply.
You could lower the resistor between the two gain stages, right before the drive pot, sending the 2nd stage into saturation much quicker... it becomes a different pedal.
Have fun with your build.
Guillaume Fairfield
Fairfield Circuitry
Fairfield Circuitry
- MicMicMan
- Breadboard Brother
I think the tension limit accepted would be 12V (zener value) + the Vgd threshold of the mosfet (given it's a p channel), right ?fairfield wrote:The zener is there to protect the mosfet. Max Vgs is 20V, in the rare case that this would happen, the zener would limit this to whatever value you got. I'm not sure about this but I think you could still use 18V with a 12V zener. As the zener conducts, the voltage drop on the 2M resistor goes up...
- jwpartain1
- Breadboard Brother
Hey, just got this pedal together, I think I'm having trouble with the 3DPT. Bypass signal gets through, but when I engage the effect, it's like I'm still in bypass. Can somebody check this for me?
On the 3DPT:
Top left lug: I've got Input from board and a jump to bottom-middle lug
Top-mid: LED ground
Top- right : board output
Mid-left: IN jack
Mid-mid: grounds
Mid-right: OUT jack
Bottom left: jump to bottom-right lug
Thanks you guys.
On the 3DPT:
Top left lug: I've got Input from board and a jump to bottom-middle lug
Top-mid: LED ground
Top- right : board output
Mid-left: IN jack
Mid-mid: grounds
Mid-right: OUT jack
Bottom left: jump to bottom-right lug
Thanks you guys.
- jwpartain1
- Breadboard Brother
Or I might be getting thourhg the bypass in the right way.. My drive knob makes the signal bassier with the SAG all the way back, but other than that no big changes other than minor volume changes when I mess with knobs. Any ideas from y'all who have the circuit down?
- jwpartain1
- Breadboard Brother
OK, so I've got signal, I had a problem with the way the SAG control was wired. Now, I'm getting signal through, but unity gain is max on the volume pot.. The signal I'm getting through is something like a light ring-mod, sorta distorted. I thought voltages might be the problem, so I checked the voltages at several points til I came up to lug 1 of the SAG pot (lefts the voltage out to the 2 JFETS and 2n2222) and measured 3.8V (9 V battery was approx 7.5V) when all the way open and 3.6 V when closed. I've checked the signal path and everything is kosher, so any ideas why I'm getting such a huge V drop across the sag pot?
- jwpartain1
- Breadboard Brother
Should the SAG pot really be wired as shown in WhiteKeyhole's schem? With 2 & 3 wired together?
- jwpartain1
- Breadboard Brother
Thanks Mr. Fairfield, I had several problems with my build that are now fixed, I mistook GATE for SOURCE on the J201's... This pedal is awesome, and a super design.
..now I'm just GAS-ing for your Randy's Revenge! Have a good one y'all.
..now I'm just GAS-ing for your Randy's Revenge! Have a good one y'all.
- jwpartain1
- Breadboard Brother
Hey, just wanted to share my build, first build actually. My wife painted it for me using acrylic paint (brushed) and we sprayed a lacquer on top. The switch on the side puts a 15k resistor in parallel with R6, dropping R6 to something like 10K if I'm correct. Mr. Fairfield had suggested subbing in a smaller value for R6, so I tried it out, sounds dirty Anyways, thanks to Mr. Fairfield and everyone else here.
And about the guy, we couldn't tell if "Barbershop OD" was referring to a barbershop quartet or.. an actual barber-shop, so we combined the two! The candy-cane was supposed to be a reference to a barber's pole.
And about the guy, we couldn't tell if "Barbershop OD" was referring to a barbershop quartet or.. an actual barber-shop, so we combined the two! The candy-cane was supposed to be a reference to a barber's pole.
- Attachments
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- 110218-192830.jpg (125.38 KiB) Viewed 4399 times
Hey, y'all...my contribution to the thread. Not built, but I think it's okay.
I built this one, but having a bit of trouble with the sag control - the pedal only passes sound from 0 - 5. It sounds amazing when full on, so I really want to get this sorted!
My voltages are
q1 - D 5.78 S 0.73 G 0
q2 - D 6.37 S 0.51 G 0
q3 - C 9.3 B6.37 E 5.81
Any ideas? Do those bias voltages look okay?
My voltages are
q1 - D 5.78 S 0.73 G 0
q2 - D 6.37 S 0.51 G 0
q3 - C 9.3 B6.37 E 5.81
Any ideas? Do those bias voltages look okay?
- cortezthekiller
- Breadboard Brother
Hey,
I posted the layout for the Barbershop on page 2 which I drew on paper traced from an actual unit. It shows that the last stage transistor (2N2222) is actually oriented upside-down compared to the "verified" schematic. I've built a few units with the 2N2222 upside down as shown in the drawing and it works quite well. Is there anyone who can verify if that is the actual orientation in the barbershop or if I somehow drew it backwards, built it backwards, and had it work?
Thanks
I posted the layout for the Barbershop on page 2 which I drew on paper traced from an actual unit. It shows that the last stage transistor (2N2222) is actually oriented upside-down compared to the "verified" schematic. I've built a few units with the 2N2222 upside down as shown in the drawing and it works quite well. Is there anyone who can verify if that is the actual orientation in the barbershop or if I somehow drew it backwards, built it backwards, and had it work?
Thanks
Verified this layout and it works flawless. Instead of a sag pot I used a dpdt switch with 2 resistors to get 9v, 7v and 5v since they seem the be the setting I used the most.asimplesample wrote:
Hey, y'all...my contribution to the thread. Not built, but I think it's okay.
- pietro_moog
- Breadboard Brother
astatine wrote:I built this one, but having a bit of trouble with the sag control - the pedal only passes sound from 0 - 5. It sounds amazing when full on, so I really want to get this sorted!
My voltages are
q1 - D 5.78 S 0.73 G 0
q2 - D 6.37 S 0.51 G 0
q3 - C 9.3 B6.37 E 5.81
Any ideas? Do those bias voltages look okay?
i have the same problem here
Hi everyone.
Im trying to build this pedal, but I've found about 5 different layouts and there are some differences in parts.
They all agree on Q1 & 2 being J201's, and the Q3 being a 2N2222.
IS the ATP2222A a good replacement for the 2N2222?
And in some schematics, they have a Q4 VP3203 > others omit this. Is this part necessary or not?
Lastly, does the wattage rating of the 15v Zener Diode make much of a difference?
Thanks guys.
Im trying to build this pedal, but I've found about 5 different layouts and there are some differences in parts.
They all agree on Q1 & 2 being J201's, and the Q3 being a 2N2222.
IS the ATP2222A a good replacement for the 2N2222?
And in some schematics, they have a Q4 VP3203 > others omit this. Is this part necessary or not?
Lastly, does the wattage rating of the 15v Zener Diode make much of a difference?
Thanks guys.
The tone switch could change between different capacitors to cut the highs (ex: none-100pF-500pF).
Whats the purpose of the 47 ohms resistor (R10)? is part of the protection circuit?
Whats the purpose of the 47 ohms resistor (R10)? is part of the protection circuit?