New wiring experiment goes wrong, kinda

[Newc]

I had an idea to use a 6-way rotary switch as a pickup selector on a 2-hum guitar hooked up to a pair of concentric Volume pots (outer 500K, inner 250K), and use a push-pull to select between the two pots.

The rotary switch provides 6 separate connections, as opposed to bridged connections, so I was able to get 6 independant wiring options:

1 Bridge full
2 Bridge split
3 Bridge full + Neck full
4 Bridge split + Neck split
5 Neck split
6 Neck full

Once I finally got the pickups wired properly (took about 2 hours because of the way the dual-layer switch had to be jumped), I connected the push-pull to the concentric pots:

Switch Down = 500K
Switch Up = 250K

So that gave me 12 tonal options:
1 Bridge Full 500K Volume
2 Bridge Full 250K Volume
3 Bridge Split 500K Volume
4 Bridge Split 250K Volume
5 Bridge Full + Neck Full 500K Volume
6 Bridge Full + Neck Full 250K Volume
7 Bridge Split + Neck Split 500K Volume
8 Bridge Split + Neck Split 250K Volume
9 Neck Split 500K Volume
10 Neck Split 250K Volume
11 Neck Full 500K Volume
12 Neck Full 250K Volume

It was a rousing success! Massive tonal variety out of 2 humbuckers, a push-pull switch, and one pair of concentric pots.

Except the concentric pot only has a 1/4" long threaded collar, which makes it entirely too short to mount on anything other than a pickguard.


So I have to drop the idea until I can find concentric pots with a longer shaft. Yay.

Or I could put the Dremel to it and route out the inside of the cavity, but I would basically be mounting the pot on a 1/8" veneer.
Ummm. No.

So, does anyone know where to find long-shaft concentrics?

[Diego]

If the pots have the common split like this

[img]http://i300.photobucket.com/albums/nn15/Diegosfb/Potenciometros.jpg[\img]

The you can fit a shaft there to make it longer but you ll have to find the knobs that go with that shaft, and that can be kind of hard

[Diego]

Sorry I think I made a mistake in the photo link

[Rich#6]

6ways are rare enough, but finding a long shaft won't be easy. What are you trying to use it in?

[Newc]

The 6-way shaft is fine, it's the conentric's threaded portion that's too short (the part that sticks above the surface of the guitar so you can actually mount it to the body).

I'm using it in one of my NASLs.

Just thought it would be neat to have the 500/250K option for either setting at the flip of a switch.

[Rich#6]

I have pushed it on some by leaving the inside washer off and cutting off the tap but not on an archtop.
Great Idea though!

[Newc]

Yeah, even with the inner washer off, it's still too short. It's only 1/4" long. I'd need at least 1/2" to get the nut to touch the top thread, 3/4" would be better.

Can you wire a 250K resistor to a 500K pot and turn it into a 250K pot that way?

[rjohnstone]

Did some checking and short of a custom order, CTS does not make long shaft stacked concentric pots. They only make 1/4" and 3/8" shafts on these.

I also checked all my usual places for electronics and none of them list a 250k/500k stacked pot that is longer than 3/8".

[Newc]

Yeah, I've been to StewMac, GuitarElectronics, GuitarpartsResource, GuitarPartsDepot, and CTS too. Looks like I'd hafta do the 250K resistor mod.

[DHardmanJr]

Check out mouser

Yeah, I've been to StewMac, GuitarElectronics, GuitarpartsResource, GuitarPartsDepot, and CTS too. Looks like I'd hafta do the 250K resistor mod.

Did you try mouser.com? Usually if mouser doesn't carry it, it doesn't exist.

Dave

[Diego]

Try digikey too !!

[Newc]

Neither one even lists a concentric pot.

[satyr]

Hey Newc
If you are only using one Vol pot at a time, get a 2 deck 500K (One shaft ,2 pots), and use your push pull to use either 1 or both pots in parallel...this will give you a 250 or 500 k pot.....cheers.

[Newc]

That's a stacked or dual-concentric, isn't it? Is there a difference between "stacked" and "dual-concentric"? I thought they were the same, but IIRC I have seen both....somewhere.

[satyr]

Hey
The coencentric has an inside and an outside shaft...like the old car stereos ...vol.in the middle with the tone outside around the bottom of the knob..
I found lots of knobs for these, but not pots!! but I think you want the stacked (2 or 3 deck) I have a supplier I have used....they are easy to get..like the pickup fader controls.
The ones I saw yesterday are sold for guitar...3/8 long...thread 7mm shaft.I have used them on a Les Paul..although not much thread sticks out....and couldn't use the washers.