Comments on: Wah Pedal Buffer

By: admin

admin — Tue, 03 Jan 2012 16:02:02 +0000

Measure the voltages on the jfet pins to see if they are correct. Should be 9v on the drain, 4.5v on the gate and around 3.8v on the source.

regards, Jack

By: Anton

Anton — Mon, 02 Jan 2012 02:09:45 +0000

I added this to my wah but it didn’t last? For some strange reason the FET went? I had this glued onto the inside of my rev. D Crybaby, it was working fine but last night at a friends place it was no go? Any reason why it would go belly up?

By: admin

admin — Fri, 08 Oct 2010 21:52:40 +0000

Yes, it needs the cap or the DC from the buffer bias will flow through the wah-pot and could make it noisy… also the 100k pot would then be in parallel with R3 and change the DC bias.

By: yeeshkul

yeeshkul — Fri, 08 Oct 2010 07:00:05 +0000

Jack does the buffer have to have an input cap at all? I see there is a 220n cap in front of it.
Thank you very much, i also had troubles with the distortion and had to change J201 to MPF102.

By: brenton

brenton — Mon, 04 Oct 2010 22:26:24 +0000

the gcb-95′s have an input and an output buffer, emitter followers. the output buffer you put in is redundant. if i were you i would replace the bipolar emitter follower with a jfet source follower right on the board; removing the existing components and replacing them with mr. orman’s since they will have the same topology (maybe except for the input voltage divider) and jfet’s clip more tastefully.

By: furaquinho

furaquinho — Wed, 29 Sep 2010 00:12:51 +0000

I finally found some j201′s and got to build the Wah Pedal Buffer. I hot glued it to one of the inside walls of the pedal.
However, during assembly, I noticed that the circuit already had a buffer at the input of the effect. It’s a late 90′s Dunlop GCB-95, and I guess it’s basically the same circuit they’ve been using to this date.
Since I can do without this buffer, is it possible to reroute it and place it between the effect’s output and the on/off switch?

By: furaquinho

furaquinho — Wed, 21 Jul 2010 05:00:50 +0000

Uh… I finished reading the AMZ Simple Jfet buffer article… Sorry, redundant question… And by the way, thank you, Jack. I’m currently and extensively using a Mosfet booster that I made out of veroboard, with the Mil bypass (can’t find 3PDT’s either, so…) and couldn’t be happier.

By: furaquinho

furaquinho — Mon, 19 Jul 2010 11:43:32 +0000

Is it possible to use a 2N5457 as a replacement for the J201? I just can’t seem to find them where I live. And, if so, would it require me to change the value of any of the other components?

By: roseblood11

roseblood11 — Sat, 11 Jul 2009 19:44:20 +0000

Why did you choose an electrolytic cap for C2? Wouldn´t a film cap be better?

By: Mich P

Mich P — Sun, 11 Jan 2009 11:05:59 +0000

You can change C2 for a 10uF
It drives the fuzz better.
Thanks for your cool website.