I've used tube preamps with solid state amps for several years now. I was carefull about turn-on and turn-off sequence at first, but found three of my preamps could be turned on and off while leaving the amp on with no ill effects. They were a BAT VK-31SE, Kora Eclipse, and Audio Research Reference TWO mk II. With the Audio Research preamp I do mute it before I turn it off. The Kora had a built in "warm-up while muted" turn-on sequence. I left the BAT in standby mode so when you turned it on it had a short warm-up delay and then was ready to go. I would think the amp you partner it with could make a diffence in the behavior, also.
