DC heaters and voltage regulator for relay switching

[Curranm]

OK I got a DC heater supply working in a new amp build, this is a 2 channel amp and I want to use the relay board and relay from the kit page here to change channels. can I use the regulator right odd the 6.5vDC tap to do this. it is already filtered and stable. IF I can as is. where do I ground the regulator since the regulator board that I buy here is a "floating ground" set up. I am definitely in the weeds and murky water here, I am making a lot of assumptions about how this works because I have never done it before. BUT I have the switch, relay board and foots witch jack wired like I do for my other 2 channel amps that are using BOTH the regulator board and the relay PCB from the parts shop here.

[pdf64]

Be aware that a power tube short (eg screen grid to heater) could blow the 100 ohm balancing resistors and pull the whole heater circuit up to HT voltage.
Hence it would be a good idea to plan for, and put in mitigation to accommodate that, so as to limit collateral damage to an acceptable level.
Referencing the relay supply to 0V may work out counter to that goal?

[Curranm]

damn it here is the correct schematic!! I had removed the 100R's because the AC heaters are getting ground reference from the rectifier ground! and reviewing the relay pages it looks like I can just ground the regulator to the chassis as long as I use an isolated or cliff jack foot switch jack, correct?

[pdf64]

A tube short of the type described previously will fill the amp chassis with conductive electrolyte due to those caps exploding, necessitating a big clean up job and rebuild / rethink of the heater and relay supply