Leave it on?

@larryi  Thanks!  Very helpful and just the info I was looking for.  I’ll contact my preamp manufacturer and ask them. 

@soix 

Yes, definitely ask the manufacturer on that. The more sophisticated (expensive) balanced tube preamps I’ve owned (ARC Ref 6, Rogue Hera, VAC Master) have relay-timed outputs: the outputs are not "live" during a warm-up period, and are first disengaged on shut-down. These have been OK when I’ve inadvertently violated the usual start up / shut-down order - no thumps. BUT I think for general "gear hygeine" it’s still smart to stick to the usual order, as much as possible. But also, these days, with all the protection options available, I think it’s very hard to justify manufacturing any preamp that could cause an awful THUMP in speakers!

@mulveling  Yeah I tend to agree.  My preamp is from Linear Tube Audio and it’s hard to think they’d engineer something that’s capable of blowing my speakers no matter how it’s used, but still I’m gonna check just to make sure.  Peace of mind, better safe than sorry, etc.  

@gano if global warming was so dire, then we shouldn't even be listening to stereo equipment, it's not a necessity.

@invalid I have no idea what that means.