I used one of those cheap switch boxes off Amazon and it worked fine.
I had a hafler xl280 and a Jolida brc 1000 tube amp hooked up to my acoustat 2+2’s.
if I was going to listen for just 20 min, I’d go sand amp, 30 or longer- tubes!
The problem is they accept very thin wire ( 16g? I don’t remember).
I had to connect thin wire to my 10g wire.
With that short a run ( few inches) and minor effect of switch, I detected no degradation in sound. I think I have a Niles unit.