Cap Values for Selectable Ranges Wah Mod on geofex.com?

[kberanek]

Hi my name is Karl, this my first post!

Has anyone tried the selectable ranges mod from geofex.com? What cap values work good?

I don't wanna buy caps that will move the sweep range out of the usable frequency spectrum, so I thought I would consult with the diystompboxes community.

I have a Thomas Organ Crybaby with TDK inductor, I replaced stock Rq value with 47k resistor and swapped out Cin with a .022uf cap.  Oh and I true bypassed this bad mamma jamma!

[.Mike]

I just ordered parts for a wah pedal, and I included this mod. Since I'm still pretty new at this and I have to order everything online, I do a ton of researching and reading. For this mod, I searched high and low for suggested values and had a hard time finding any recommendations. Eventually, I found them at GGG:

http://www.generalguitargadgets.com/bom/wah_mod_notes.txt

Capacitors (C2a-f)
Bigger value caps = lower frequency range

Suggested values; 5n6, 8n2, 10n (original), 15n, 22n and 33n. Try and see
what you like. Use a 6PDT rotaryswitch with 'break-before-make' contacts.
You can place a 1M-resistor over every pole on the switch stop the popping
(which is really loud!) when switching when the wah is in use.

That may be a good place to start.

Mike

[kberanek]

Awesome! Thanks!

[Outlaws]

Capacitors (C2a-f)
Bigger value caps = lower frequency range

Suggested values; 5n6, 8n2, 10n (original), 15n, 22n and 33n. Try and see
what you like. Use a 6PDT rotaryswitch with 'break-before-make' contacts.
You can place a 1M-resistor over every pole on the switch stop the popping
(which is really loud!) when switching when the wah is in use.

RE: The resistors....  What do they mean "over every pole"?

[tehfunk]

I actually just did this mod, here's the pictures, the other mods i did are in the pictures thread.


I went with the following values: .0068 uf, .01 uf, .012 uf, and .015 uf. I must say they are all very usable, in fact sometimes it's almost a little hard to choose. There is definitely a difference at the end of the each spectrum. If I could do it again i think i'd go with the same first two but .015 uf and .022 uf for the bassier ones. About the popping issue, it's really not that severe, before I did mine, I researched a famous and well liked pedal to see if there's had pops, I'm referring to the fulltone clyde deluxe, and it does. So, if it's good enough for someone who is gonna pay like 200 bucks for a wah it's good enough for me . To sum it up, I highly recommend the knob, but I suggest keeping it down to 4 total caps keep it simple. And, one major piece of advice, when you get that switch, if it's the sturdy plastic kind made by mouser, don't let the little metal washer fall out, it determines how many positions the switch has, and if you screw it up it can be a little pain to get back to before, but I would recommend those over the big metal ones with the wafers. Hope that helps, and good luck!

[Outlaws]

http://www.generalguitargadgets.com/diagrams/wah_mod_lo_rotary.gif

Where do the resistors go to reduce popping?

I got this 1P6T switch: http://www.smallbearelec.com/Detail.bok?no=581&sfs=982ee11b
I have never used one.  I don't get what the other two pins not labeled are for.  There are 5 on top and 5 on the bottom.

Also, I still need that other rotary switch.  Is the one I got a decent one?  Otherwise I will get another when I order this one.  Any have a flat on the shaft?  I am going to grind the one I got so the set screw has something more to grab.

[tehfunk]

http://www.generalguitargadgets.com/diagrams/wah_mod_lo_rotary.gif

Where do the resistors go to reduce popping?

I got this 1P6T switch: http://www.smallbearelec.com/Detail.bok?no=581&sfs=982ee11b
I have never used one.  I don't get what the other two pins not labeled are for.  There are 5 on top and 5 on the bottom.

Also, I still need that other rotary switch.  Is the one I got a decent one?  Otherwise I will get another when I order this one.  Any have a flat on the shaft?  I am going to grind the one I got so the set screw has something more to grab.

I am not familiar with the one you got, though if you go to the alpha page you will probably be able to find a datasheet for it. The one I got has a flatted shaft, here I'll give you a d shaft 1p6t version if you want to buy a different one, and the d shaft knob i used. About the 3p3t, I would look on mouser for one, as I can't seem to find one in that exact same model, and I'm not sure what specifically you are looking for. Hope this helps.

1P6T d-shaft http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMvNbjZ2WlReYgyU92IkYgpfnacaK2O1Kwo%3d
Red-topped d-shaft knob. http://mouser.com/Search/ProductDetail.aspx?R=450-WB118virtualkey56100000virtualkey450-WB118

[Outlaws]

http://www.generalguitargadgets.com/diagrams/wah_mod_lo_rotary.gif

Where do the resistors go to reduce popping?

I got this 1P6T switch: http://www.smallbearelec.com/Detail.bok?no=581&sfs=982ee11b
I have never used one.  I don't get what the other two pins not labeled are for.  There are 5 on top and 5 on the bottom.

Also, I still need that other rotary switch.  Is the one I got a decent one?  Otherwise I will get another when I order this one.  Any have a flat on the shaft?  I am going to grind the one I got so the set screw has something more to grab.

I am not familiar with the one you got, though if you go to the alpha page you will probably be able to find a datasheet for it. The one I got has a flatted shaft, here I'll give you a d shaft 1p6t version if you want to buy a different one, and the d shaft knob i used. About the 3p3t, I would look on mouser for one, as I can't seem to find one in that exact same model, and I'm not sure what specifically you are looking for. Hope this helps.

1P6T d-shaft http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMvNbjZ2WlReYgyU92IkYgpfnacaK2O1Kwo%3d
Red-topped d-shaft knob. http://mouser.com/Search/ProductDetail.aspx?R=450-WB118virtualkey56100000virtualkey450-WB118

Thanks.  I will get that switch.
Would this one work for the 3P3T?  http://mouser.com/Search/ProductDetail.aspx?qs=6uASyQ2j9sfVscPufHNV9w%3d%3d
I am not too familiar with rotary switches.  Its not a D shaft, but I am not finding too many options.

[tehfunk]

http://www.generalguitargadgets.com/diagrams/wah_mod_lo_rotary.gif

Where do the resistors go to reduce popping?

I got this 1P6T switch: http://www.smallbearelec.com/Detail.bok?no=581&sfs=982ee11b
I have never used one.  I don't get what the other two pins not labeled are for.  There are 5 on top and 5 on the bottom.

Also, I still need that other rotary switch.  Is the one I got a decent one?  Otherwise I will get another when I order this one.  Any have a flat on the shaft?  I am going to grind the one I got so the set screw has something more to grab.

I am not familiar with the one you got, though if you go to the alpha page you will probably be able to find a datasheet for it. The one I got has a flatted shaft, here I'll give you a d shaft 1p6t version if you want to buy a different one, and the d shaft knob i used. About the 3p3t, I would look on mouser for one, as I can't seem to find one in that exact same model, and I'm not sure what specifically you are looking for. Hope this helps.

1P6T d-shaft http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMvNbjZ2WlReYgyU92IkYgpfnacaK2O1Kwo%3d
Red-topped d-shaft knob. http://mouser.com/Search/ProductDetail.aspx?R=450-WB118virtualkey56100000virtualkey450-WB118

Thanks.  I will get that switch.
Would this one work for the 3P3T?  http://mouser.com/Search/ProductDetail.aspx?qs=6uASyQ2j9sfVscPufHNV9w%3d%3d
I am not too familiar with rotary switches.  Its not a D shaft, but I am not finding too many options.

From the looks of the datasheet, it should work. good luck with your project.