Examples of high voltage relay

[CascoSieg]

I'm considering a design posted by Jojokeo with input stage (12A_7) switchable between parallel triodes and cascaded. The schematic posted requires switching the signal path, as well as the B+, to separate the plate load resistors, but I'd like to run it from a footswitch. I only have experience with low voltage signal-path relays that Doug supplies.
Anyone have examples that would well for B+ voltages?
Thanks!

[tubeswell]

The relay can still be powered by 5 to 12v. You don’t need to power it with 400v.

[sluckey]

I'm considering a design posted by Jojokeo with input stage (12A_7) switchable between parallel triodes and cascaded. The schematic posted requires switching the signal path, as well as the B+, to separate the plate load resistors, but I'd like to run it from a footswitch. I only have experience with low voltage signal-path relays that Doug supplies.
Anyone have examples that would well for B+ voltages?
Thanks!

I'd like to suggest that before researching to find a proper relay that you build the circuit and use toggle switch(s) to do the switching. This will allow you to test the circuit before committing to a relay. It could be that you don't even like the results.

[CascoSieg]

@Tubeswell - Yes, I figured I could run the relay off my 5v circuit, but can I get a switch mechanism with internals rated for 400v?  Or maybe the plain ol' relay setup is perfectly fine... I can't really tell from the posted ratings.
@Sluckey - For sure, will mock it up on a test board first. But if it's complicated or costly to find a relay actuated switch (opto-isolator?) for it, I'll forgo the idea. The reason for having the foot-switchable cascade option is to better drive an OD circuit, so it would be mainly used for that, but I have other options. Otherwise, for cleans, I like the parallel triode mode.
Thanks!

[PRR]

24V AC coil relays with 240VAC 5A contacts are standard items in heating/cooling work. The same frame and contacts are available at 12V and DC. I'd hope 240V 5A contacts would stand many uses at 400VDC 5mA (in resistance load, not inductance). These can be found cheap enough to get a socket and a spare. (No, not in Doug's shelves.)
https://www.digikey.com/en/products/detail/omron-electronics-inc-emc-div/G2R-1-DC12/368669
https://www.amazon.com/s?k=dc+12v+relay
https://www.amazon.com/API-ELE-Warranty-Electromagnetic-Power-Indicator/dp/B07KMC8MW7
https://www.amazon.com/dp/B07SYHNVHN
https://www.parts-express.com/electronic-parts/relays/general-purpose-relays-sockets

There are also 12VDC relays for car headlights, blinkers, and my O2 heater. They are not rated for high voltage on the contacts but they are VERY beefy inside and also quite cheap (carry spares).
https://www.digikey.com/en/products/detail/cit-relay-and-switch/A2F1CSQ12VDC1.6/12418826
https://www.amazon.com/s?k=dc+12v+relay

100% agree: TRY (by hand) before you buy (a lot of relays and wire and supplies). It might be a thing you use twice a year. Like I just switched-over my house from heat to cool.

[DummyLoad]

https://www.pickeringrelay.com/reed-relays/high-voltage/

https://www.pickeringrelay.com/pdfs/131-hv-mini-sip-1500v-reed-relays.pdf