Potentiometer & Power Switch Help

[emretelci]

Hi there,

I am making a stereo tube amp. I am using a 100K dual (ALPS, six legged) pot for volume.

Instead of having another power switch, I want use a rotary volume pot with built-in on/off. So basically, I need 100K dual on/off volume pot.

I can't find an unused dual one. All I find is mono (with three legs) Maybe I am looking at the wrong places. Is there any place that I can find good quality dual pot with on/off?

Thanks...

 

[DF96]

They can be be harder to find nowadays. Most commercial electronics have moved away from them, partly because they often have a separate PSU and partly because the pot wears out more quickly if has to be moved every time you switch on or off.

 

[azazello]

Not good idea...AC near to audio signal....

 

[petertub]

As far as i now pots with power-switches has not been made in 20 years. If you find one then the chances of obtaining a spare is minimal.

You _might_ make one with a microswitch and a cam om the pot shaft, the cam
activating the switch at bottom level. But i admit it's flaky as best , better is
to use a separate power switch it's safer, it may be replaced in the future.

 

[Eli Duttman]

As far as i now pots with power-switches has not been made in 20 years.

As the OP stated, you can still buy them, but they are not "ganged"/stereo. Alpha (Taiwan) item # RV16A03F-10-15R1-B5K is an example.

Not good idea...AC near to audio signal.

Agreed.

 

[Ketje]

because the pot wears out more quickly if has to be moved every time you switch on or off.

I remember long ago there where potm.s with a push-off/pull-on switch, no useless turning.Dono if there are still made.
Mona

 

[wa2ise]

Another problem with a power switch on the volume control is that when you turn it on, you don't hear the audio for the warm up time. And maybe you turned it up too high, 20 seconds of quiet, and then you get blasted until you run over to the amp to turn it down.

 

[Merlinb]

Perhaps you could use a pot with a momentary push-switch, which are quite common? This could in turn control a relay to switch the mains.

 

[emretelci]

Thank you very much all. I think using a separate power switch will be a lot better according to your comments...

Cheers...