Dual concentric pots, 500K/100K and 250K/250K needed!

[BillyJ]

Does anyone have a sourch where these could be found in lower quntities?
Thanks!

[Paul Perry (Frostwave)]

Stewart Macdonald guitar parts catalog has some pretty weird pots, not sure whether they have these though.

[drew]

I bet you could buy one of each of the values you want, in a dual-gang style, then disassemble them and put them back together as a halfbreed pot!


drew
www.toothpastefordinner.com

[BillyJ]

Thanks guys! Stewart NCdonald didn't have exactly what I needed but did have some so I may rethink things and see if I can fiddle with some tapers and stuff. Good time to get down witht hat math not that I have a better uderstanding of what's shaking (thanks Jason Stout!).
Drew I tried that the other day and I just made a wreck of the whole mess. If anyopne knows of any particular brands that come apart and go back easily again I might try this again.
Back to the drawing board as it were.
Big thanks though gentlemen it gets me closer!

[J Gagan]

Are you looking for a dual gang with different values or a concentric dual shaft pot like the car stereos used to have? If this is what you are needing, try a surplus electronics place or old car stereo repair shop.
I just built a vintage looking round fuzz with two holes but it needed three controls so I used an old car stereo type concentric inner outer shaft dual pot. pretty trick. Found it at my electronics surplus place.

Rg Keen's "secret life of pots" is a great resource for doing fun mods to pots.

If you are simply looking for a dual gang with different values in each section, the alpha dual gangs come apart and go back together pretty well. Buy the second value in a single gang and swap the guts in.

Radio shack usually has Alpha type pots and also sells a kit to install a clickswitch by disassembling the pot and adding a second piece on the back These usually go together pretty easy. perhaps you could try it with those? their selection of values is pretty limited tho.

[Mark Hammer]

The need for any of these specific pots would depend on whether you intend to use them as voltage dividers or simply variable resistors.  If all you wanted to do was have one control operating a 0-500k resistance and a 0-100k resistance at the same time, then all you need is a dual 500k or dual 1meg and suitable parallel resistors.  Same goes for the dual 250k.

Of course, if you wanted to use them as voltage dividers and the circuit in question is sensitive to the specific pot value, then you may encounter a little more difficulty.

Although in principle you CAN simply hoist a resistive element from one single or dual-ganged pot to another of identical dimensions, you'll need to be careful about damaging it, about installing it facing the right way, and about securing it to the lug-rivets.  Not as difficult as defusing a time bomb, but still tricky.

[BillyJ]

Yeah I need dual concentric.
I will try some car audio places, that sounds like a good lead. I would have never thought of that but it makes sense.
I think if go and read sectret life of pots again I will get it this time.
Been meaning too for weeks but sometuimes I wind in circles checking all the stuff out there that it takes me forever.
I almost got there last night but only got as far as technology of the wah, my other fascination these days.
Thanks for all the help gents. I should be able to figure something with all the leads and information.