Bigger Inductors?

[need_a_haircut]

we all know most wah circuits use a typical 500mH inductor.

i've recently salvaged a stack of inductors from the vibrato and "voice" circuits of a beyond-repair organ, and am looking at building a freestanding wah (ie: non-rocker). most are either 1H or 2H, italian-made and in red plastic cases.

does anyone have any experience in sustituting a significantly-bigger inductor into a typical wah circuit (ie: vox, crybaby, etc) and what the result would be in terms of voicing, response etc? i'd imagine a few other components would need to be tweaked to accomodate a different value inductor, but apart from stock-standard designs i have no experience in the technology of wahs, let alone modding them.

[sinner]

Awesome, fancy to part with one?

Click in the link in my signature. Under projects -> WAHWAH/EQ you have Marshall Supa Wah. Nominal inductor value for it was 1H

[deltafred]

... most are either 1H or 2H, italian-made and in red plastic cases. ...

If you can strip them down you can remove some of the turns and drop them to 500mH.

Best done with an inductance meter or DMM that reads inductance as the number of turns to inductance is not a linear relationship so you can't just remove half the turns from a 1H to get 500mH.

[need_a_haircut]

cheers for the link. let's see if the inductors work first! the next step is to test them once they've removed from the original pcbs (i've removed the daughter boards intact, no desoldering yet).

i do have a DMM that measures inductance, but i'd like to keep them intact for the time being, especially being a component i hadn't encountered before, (as opposed to your stock crybaby etc. inductor). i should mention they are the same size and form-factor as a normal fasel inductor (red upright cylinder, radial leads).

if for instance, you sub a 2H into a typical 500mH circuit, does it change overall frequency response (akin to filter caps), the range of the effect, voicing / resonance, the earth's rotation, none of the above, all of the above?

[Hides-His-Eyes]

You could put two 1Hs in parallel to make 0.5H couldn't you?

I believe the inductance will just translate the frequency range. Some of the old Snarling Dogs wahs had an external footswitch for swapping inductors to give different freq ranges.

[need_a_haircut]

funny you should mention a snarling dogs wah, i fixed one for a friend years ago (dry solder joint, nothing major), partly what got me wanting to build my own gear. when i found these on the organ pcb, i thought of that very pedal.

i'm thinking i'll pull a 2H from the daughter board first, build a wah pcb (eventually i'm going to need one anyway), and socket (read: alligator clip) a few different values from there. i'm looking for the widest frequency range i can get, and a fairly pronounced peak. i'm aiming for the bastard child of a wah and a nasty resonant filter.

[GuitarlCarl]

brother this is a must read... R.G.Keen's Technology of Wah pedals...
http://www.geofex.com/article_folders/w ... wahped.htm

[need_a_haircut]

thanks very much for the link. i had come across that page before (and it is a great article), hadn't absorbed the paragraph about "sharpness" though. i guess Rq from that schematic will be the key to fine-tuning this particular (and yet untested) inductor.

when all is built and tested i shall post a vid / sound sample, be it nasty or nice!

[bajaman]

....just a suggestion - try using half the value of feedback capacitance for 1H choke - try 5n or 4n7 in place of the 10n capacitor - try 2n2 or 2n7 with the 2H inductors - should retain the same tuning as the basic cry baby wah circuit
bajaman

[DrNomis]

In a Wah pedal, the Inductor and Capacitor form a bandpass filter with the centre-frequency determined by the values of the inductor and the capacitor, so, going by that you should give bajaman's suggestion a try, I see no reason that it shouldn't work, the bonus is that you won't need to remove any windings from the inductor....