Wah output buffers

[thermionix]

I'm considering putting an output buffer on my Clyde circuit wah.  I really don't want to change the way the wah sounds at all, but being able to use it with fuzz would be nice.  If I do add a buffer, it would only be on when the wah is engaged, otherwise true bypassed.  I could also use a second (internal) DPDT to selectively bypass the buffer, but switches can be kind of large.

Naturally I've checked out the Axis Wah article at Fuzz Central.  Easy enough, but there are lots of other buffer circuits that could be used, and I have no experience with any of them.  Simplicity and low parts count are good, I'd rather not have to set up a bias voltage, but transparency would be the top consideration.

So, what do you folks recommend?  Have you tried the Axis Wah setup?  Got something better?

Thanks for your input.

[Mich P]

Foxrox is the best i have tried.
Mich P.

[Elijah-Baley]

I have to build the Foxrox, too.
Can I ask if I can keep a IC buffer on as first in the pedal chain with the foxrox?

[thermionix]

I've heard good things about the Foxrox, I'll be looking into it.  Thanks.

[induction]

Any decent buffer will do fine if you put a resistor inline with the output. The foxrox, for example, is a pretty basic op-amp buffer with a 22k resistor tacked onto the end.

Can I ask if I can keep a IC buffer on as first in the pedal chain with the foxrox?

A buffer before the wah certainly won't interfere with the foxrox, if that's what you're asking.

If your foxrox is a standalone box between your wah and your fuzz face, then an always on buffer up front won't be a problem when you use your fuzz face as long as the foxrox is also engaged, though your guitar volume knob cleanup on your fuzz face will suffer. If the foxrox is built into the wah and bypassed when the wah is bypassed, then having a buffer up front will give you the usual fuzz face-buffer ugliness whenever you use the fuzz without the wah.

There are many ways to solve this problem. The best one depends on how you use your pedals, but turning off your first-in-chain buffer whenever you use your fuzz face without the wah is a pretty decent solution.

Or maybe I misunderstood your question.

[Elijah-Baley]

Thank you for the explanation.
I wanted put the foxrox into a cry baby after the output of the wah board. Classic choice I guess.

[induction]

I see. That will work fine with a first-in-chain buffer, as long as you turn off the buffer when you use the fuzz face without the wah.

[thermionix]

Looking up the foxrox schematic, I found a tagboardeffects layout from a few years ago, and in the comments section Pink Jimi Photon was talking about getting better results with a series resistor on the wah output than with any kind of buffer.

So I did some experiments.  My FF build has a variable resistor (pot) at the input, and my TU-2 in bypass could stand in as a buffer.  Both setups made the wah work better with the fuzz than nothing at all, but I wasn't too impressed with either.  With the buffer the fuzz got too bright/thin.  Maybe the TU-2 isn't a great example of a buffer, but it did sound nice going clean into the amp.

FWIW, I also tried a little of both, TU-2 buffer and some input resistance on the fuzz.  I guess that's a better approximation of the Foxrox.  I don't know, still undecided at this point.

[thermionix]

Any decent buffer will do fine if you put a resistor inline with the output. The foxrox, for example, is a pretty basic op-amp buffer with a 22k resistor tacked onto the end.

Do you think the (simpler) Axis Wah output buffer with the output resistor would do well?  I have a 2N5457 already, and discreet gives me the option to hand-wire, as I don't yet make PCBs.

[drummer4gc]

If you're looking for simple, try just a resistor in series with the wah output, no buffer. I've used a 51k for this purpose in the past and it worked pretty well.

[induction]

Do you think the (simpler) Axis Wah output buffer with the output resistor would do well?  I have a 2N5457 already, and discreet gives me the option to hand-wire, as I don't yet make PCBs.

I think it would work to cure the screeching, definitely. Whether you can hear a difference from the foxrox, and if so which you prefer, I wouldn't want to speculate. It would be very easy to give it a whirl on the breadboard to see if it does the trick for you.

The suggestion of a single naked output resistor has merit as well, and is even easier to breadboard.

[thermionix]

Ha!  I don't have a breadboard, but it would be funny to see somebody use one for a single resistor.  As I mentioned above, I already tried the series resistance with the input pot of my FF.  It's a 100KL wired as a variable resistor, and about halfway up was where it worked best.  But I still wasn't thrilled with the result.  I have more experimenting to do.

[induction]

You might also want to try the AMZ pickup simulator after a buffer. I've used it with a basic op-amp buffer and a Radio Shack transformer for the inductor.