On Fri, 11 Mar 2011 09:24:49 +0000, Adrian Brentnall wrote:

HI Folks
Does such a thing exist ?

As others have said, they used to, but might be hard to find now. The
ones I recall had the switch on the rear of the pot, and had a cam
attached to the shaft which operated spring-loaded switch contacts. It
might be difficult to make something like that, but if you found a pot
with a long input shaft (assuming those are still available too, even!)
then maybe you could homebrew something on the front-side (along with a
metal bracket to mount it all onto the front panel).

Is this for a main power switch, or something else? Adding an interrupter
and an optical switch would be relatively easy[1] I think (more so than a
nice clicky on-off switch) but does have the disadvantage that you still
need to waste some power in the 'off' state.

[1] heck, you might even find a suitable pot that you could somehow graft
that onto the back.

....and I can see dual-gang pots without switches, and single-gang pots
with switches - but not 2-g with switch.

Hmm, maybe with a bit of jiggery-pokery the switch from a single-gang
will transfer to an unswitched dual-gang?

cheers

Jules