[Amps] OK to run HV power supply with no load?

[Bill Dzurilla]

In connection with my homebrew 6m 3-500Z amp that we discussed in an earlier thread, I would like to try a test with a power supply from a different amp.  The homebrew amp's internal power supply has B+ and B- wires running from the Harbach board.  For the test, I'd like to remove just these 2 wires and connect the B+ and B- to the external p/s.  However, the internal p/s would remain powered up to run the filaments, fan, and relay.  

Is there any problem with this idea?  In particularly, is it OK for the Harbach board to be connected with no load?

The test would be far more difficult if I have to disconnect the internal p/s completely.

73, Bill NZ5N