correct way to turn off tube preamp


I recently purchased a tube preamp. My other equipment is SS which I leave on 24/7. From what I have read I don't want to leave the pre on all the time. When done listening is it ok to put the amp in standby mode, then turn off the pre?,, or should I turn off the pre--leaving the amp on and then going to standby mode on the amp. When I do the latter I get a very samll 'thump' heard through the speakers. Thank you.
classical1

Showing 4 responses by dougmc

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.
Dragon1952 - Thanks for the information. One question. When you turned off your preamp before your amp, did you turn the volume control on the preamp down all the wasy before turning it off?

The instruction from Manley's manual implies that the harmful noise or transients originate in the preamp or the source. If an amp produced noise that endangers the speakers when the amp is turned on or off, the sequence in which the amp is turned on or off wouldn't matter because the amp feeds directly to the speakers. It's interesting that the component with the most amplification power poses the least danger to the speakers (or amp designers adquately address the problem).

Dragon1952 - In your second post, in explaining why you should have a source connected to a tube preamp, you analogized to the load placed on an amp by the speakers. However, the amp, not the source, is the load on the preamp. I'm not suggesting that both statements you made aren't true, just that the analogy seems off.
Newbee - Thanks for your explanations and the advice about starting a new thread when interest starts to tail off. I thought I was still in time on 06/09, but when no responses came in for several days I should have started a new thread.