Aikido line stage - plus phono line stage

[cjkpkg]

I am at the early stages of building an Aikido 5687 line stage. I also want to integrate RJM's 6DJ8 phono stage into the chassis for an all in one preamp.

I have all the iron figured out - I am using a separate 12.6V xformer for all heater needs - it is a 3A unit which just gets me there.

My main question is, if I use the preamp primarily for non-phonograph use, how can I easily cut B+ and heater current so that I am not running the tubes when they are not in use?

My target B+ is 250VDC. Would a standard DPST switch rated at 250VAC be sufficient?

 

[Merlinb]

Presumably a double pole switch, with one pole cutting the HT and one pole cutting the heater supply to the phono section.
A 240V mains switch should survive- everybody uses them. The current levels are so low that you can over-voltage them quite a bit and still get long life.

Alternatively, you could just switch a resistor into the heater circuit so that the phono valves run with a reduced heater voltage (about 6V say), which will allow them to idle at reduced temperature. Since you're only dealing with low voltage, the switch rating won't be a problem.