correct way to turn off tube preamp

Classical1, 85db speakers are not a problem whatsoever for a tube amp with 80wt+ power. The biggest consideration is the impedence curve of the speakers. The flatter the better and the closer to 8 ohms the better. Higher efficency will open up options for amp designs though. FWIW, althought I'm sure your are factoring this into your choice for a SS amp, be sure that your SS amp has the proper imput impedence to match the output impedence of your preamp. A lot of SS amps have lowish imput impedence. Other than that there is no reason that a SS amp won't sound just fine.

Great. I can ask some related questions without starting my own thread.

1. Many posts describe the correct order for turning on and turning off system components, but I have yet to see an explanation why. I’ve experienced “speaker thump” when turning off the electronics, so I guess avoiding that noise and its effect on the speakers is the reason for the order of turning off components (yes or no?), but what’s the reason for the order of turning them on?

2. What causes the “speaker thump”? Is it an electrical discharge by the capacitors?

3. What happens electrically when an amp or preamp is in standby mode? Since no sound is produced, I assume the signal from the upstream component is cut-off somehow. Is the entire circuit still activated by the electricity from the wall or do some parts need the signal to become activated (stay warm)?

With an integrated amp, the amp and preamp sections go off and on together. The integrated I used had a standby mode, but putting the amp in standby caused a small speaker thump, even with the volume turned all the way down. I never experimented to see what would happen if the wall plug was pulled with the unit on. Interestingly, the speaker sound was very slight if the amp was put in standby almost immediately after the music ended, but got louder when time elapsed before hitting the standby button.

Thanks for any answers.

No one has any answers?

Doug.. I've checked each day hoping your questions were answered. I too would like to know. The only thing I could answer is yes to the 1st part of question 1.. Many of the "Sage" audiogoners have forgotten more about audio than I will ever know. I've learned a lot from these forums and greatly appreciate it.. I'm hoping the venerable Sean, Newbee or one of a host of others will explain. :)

From a Manley preamp manual...
"7. Power up the preamplifier FIRST and allow it to settle for a minimum of 30 seconds before powering up your amplifiers. Turn off your preamplifier and source components LAST when powering down a system. This prevents amplification of turn-on transients and other noises when powering up or turning a system off and ultimately protects the speakers"

I'm new to tubes and got away with turning the preamp off first a few times. Then one time I heard this fluttering sound and then a pop. I powered the preamp back on and put on a CD and had no sound in one channel and a faint sound in the other. It turned out ,luckily, that I had blown 2 fuses in one channel of my amplifier and 1 fuse in the other channel.
You can do a Google search if you have a little time. That's how I found the Manley manual. It recommends, in another section, turn on sources first, then preamp...wait 30 secs, then amp and wait another minute or so before playing a source to give everything time to warm up a bit. Power off in opposite order.