Can anyone build this effect box for me?

[neckhumbucker]

Hi,

I need an auto-wah with no sensitivity, like a wah pedal being rocked back and forth very slowly regardless of string picking.
If it can have knobs for Q, peak, speed, that's be great; if not, a set of built-in parameters would also work.

I was told this is doable and I may find someone here who is willing to give it a try.
Here is the most technical info I have on the subject: "All you need is a sine or triangle wave generator driving a vactrol connected where the potentiometer goes in a wah circuit."

Thanks.

[joegagan]

george blekas of pedalworx  has one he can sell you right now. called cool machine.

contact him to see if it will go as slow as you are requesting. he may mod one for your needs.
pedalworx.com

[Mark Hammer]

The MXR Auto Q also does this, except it allows you to blend both sources of filter modulation - LFO and envelope.

[nocentelli]

Boss AW-2 as well, and you can pick them up S/H for very cheap.

[neckhumbucker]

Thanks.

I checked out MXR Auto Q, it doesn`t go as slow as I want , and wave form is kind of jerky for me. It goes from high to low slowly in the middle but at one point it dips into low very fast and comes back up very fast. I think what I want is a perfect sine wav (though I am not sure)

I have a AW-2, it is similar to MXR Auto Q, speed and wave form wise.

I`ll check out pedalworx.com.

I get this effect from Boss GT-6 now. I want to get rid of it, but this is the only effect I can`t reproduce with anything else.

When I place a delay after this effect, it creates a very interesting sound that I use in so many tunes.

Thanks for your replies.

[Mark Hammer]

The AW-2 uses a diode pair to do some wave-shaping of the LFO.  I don't know if it is sinusoidal, but it's safe to assume their objective was in that direction.

You can simply change the value of 2 caps in the LFO circuit and you'll have your very slow sweep.  Right now there is a pair of back-to-back 10uf caps.  Plunk a pair of 22uf or even 33uf units in there instead, and Bob's your uncle.  The 22uf caps will make the slowest speed up to twice as slow as it is currently, and the 33uf will make it 3x as slow.

[neckhumbucker]

sure you made it sound easy. I'll open up aw-2 and see if I can attempt. 

[Mark Hammer]

It IS easy.  You will have  things to be mindful of:

1) That you unsolder the existing parts, andsolder in the new parts carefully, with appropriate solder, making good joints and avoiding solder bridges.

2) That you orient the capacitors properly.  Make a note of which side (+ and -) of the existing capacitors goes where, and replicate that with the new ones.

3) That the new capacitors have an appropriate voltage rating, to assure they adhere to their specs.  It is hard for me to imagine you'd be buying anythng with less than a 16v rating, but I figured I'd mention it anyway.

4) That the new caps FIT in the existing space, both in terms of their width AND their height.

Once you look at enough 2-opamp LFOs, it becomes second nature to identify those same caps in any circuit.  Depending on the other component values, and the range sought, sometimes you will see 2 back-to-back electrolytic caps (to form a non-polarized capacitance), and sometimes you will see a plain vanilla non-polarized plastic or ceramic cap.  They do the same thing, but non-polarized caps can often be a larger size, and pricier, for the same capacitance value as a back-to-back pair of electrolytics.

If you are gentle with the heat, and produce decent, clean, solder joints, the mod is easily reversible if you decide it's not what you want.  Just save the original caps in case.

[neckhumbucker]

Thanks Mark.
Can this be done on AW-3? AW-3's wave form is more like what I want. but longest cycle is 4sec, if I can make it 6sec, that could work better for me.

[neckhumbucker]

george blekas of pedalworx  has one he can sell you right now. called cool machine.

contact him to see if it will go as slow as you are requesting. he may mod one for your needs.
pedalworx.com

Hey joegagan,

There is no email or phone on Pedalworx website, do you happen to have his email? Thanks.

[Mark Hammer]

Thanks Mark.
Can this be done on AW-3? AW-3's wave form is more like what I want. but longest cycle is 4sec, if I can make it 6sec, that could work better for me.

I haven't had any luck finding gutshots, but my sense is that many of the Boss effects that end in "-3" (PH-3, BF-3, OC-3, etc.) are digital in which case there will not be any simple identifiable LFO subcircuit to mod.  IN general, if you see a compact pedal that offers a bunch of "modes", it's digital.