Possibly what you write is what I mean, but I understood from your writing, that the 45s delay is more like the tubes wait for the solid state to be ready than the opposite?
1-2 minutes tube soft start time is also what I’m used to. No problem with waiting as long as I don’t need new tubes every 1-2 years (as I use little more expensive ones)
By googeling I find something like this under „tube soft start“:
Is something of this happening in the BHK for tube sake?
One thing you can adjust is when the BHK Pre sends a 12-volt trigger signal to the amp. The BHK 250 has a shorter warm-up time than the preamp so I set the trigger time so the amp completes its warmup just after the preamp.
Isn’t the intent of the 12V trigger delay to avoid any thumps or transients that may occur when the preamp comes online? By delaying the amp(s) turn on the thump simply isn’t amplified and thus not sent to the speakers. I get no thump so I have 12V delay at 0.
Yes. I don’t get any thumps when starting up my BHK system either but in general it is safer to turn the preamp on first so I set it that way out of habit.
Yes, you are right - 90 from cold and 45 from standby.
Damn, I need to learn some patience…
I really seem to have opened up a swarm of discussion here 
Anyway, I have to learn to wait the 90 seconds I suppose. It’s well worth the wait.
This preamp with the Tunsgram NOS tubes is sublime. I am hearing into my music stuff that I never heard before. Punchy but smooth - just what I was looking for in my system. It’s such a joy to discover my music collection again. I’m very late to the party but I have to say, good work PS Audio, good work BHK.
Discussion is good. 
I reread your last paragraph and concluded from „the tube heater voltage is applied full on“, that there’s no soft start for the tubes on the BHK preamp, which slowly rises the voltage in certain steps or applies any other of the described soft start options in the cited article. It seems the BHK preamp rather cares for a quick start of the solid state part by keeping certain circuits half warm. Maybe if BHK is online some time, he could put his info in, too.
When I shut off my BHK Pre, using the main power switch, the display and blue button light up for a couple seconds and then it goes into standby mode, requiring a push of the blue button or remote-on. Is this normal? I don’t see this in the manual. Is this configurable?
Mine behaves the same. I don’t turn it off via the toggle unless I’m changing tubes…so I’ve never thought about it. I’ve not seen that it is configurable.
Thanks. It’s not a problem, just a curiosity from a power cord “shootout” with some friends on day three of non stop rain.
That behavior is normal and it is not not configurable. We designed it to be used mostly with the standby button.