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Turning off tube preamp first sends solid state amp into protection?

I have been experimenting with using a vintage Luxman CL40 valve preamp as a separate preamp stage for my L-509X integrated. Because I leave the solid state amp on 24/7, I accidentally turned off the preamp while the 509X was still in Separate mode. The integrated immediately went into protection mode with the power light blinking. I powered it down into standby mode, then brought it back up and it remained in protection mode. It wasn't until I unplugged the 509X and plugged it back in that everything was cool. 

Did I do any potential damage here? What it it happens again? It's pretty easy to accidentally turn off the preamp when I'm leaving the 509X on all the time.
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harrylavo's avatar
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harrylavo
346 posts
 
n80 - That gear should give you good sound, and your sequence is correct.  But you should not have to turn off the amp once you've put it in standby.  Standby cuts power consumption to only a few watts, but keeps the capacitors formed.  It may lengthen the problem-free life of the amp.
imhififan's avatar
imhififan
2,210 posts
 
wolf_garcia4,373 posts11-18-2018 11:12am
Always turn the preamp on first and off last, although with many modern systems it might not matter much...but that's been the conventional wisdom for a while.
jeenam50 posts11-19-2018 10:06pm
smh @ wolf_garcia. Do not listen to his awful advice.

ALWAYS power the amp on last!
ALWAYS power the amp off first!
@jeenam, Your advice absolutely correct, btw, wolf_garcia is right too.
atmasphere's avatar
atmasphere
11,861 posts
 
The turn on/off order has nothing to do with tube vs. solid state. You turn on the pre-amp and sources before the power amp because the amp can’t send any of their on/off noise to the speakers until it is on. And you turn off the amp first for the same reason.
This. +1
n80
2,125 posts
 
harrylavo, thank you. I wouldn't call myself a 'green' person but I am not wasteful. If the power consumption is low (manual says 150W...which means nothing to me) I'll certainly leave it on standby. Plus, the power button is tiny and out of the way. The 'standby' button is huge.
genez
220 posts
 
If you have separates the rule is always turn the amp off first, not the preamp.  Otherwise you can easily get the same problem, be it solid state, or tube.  It makes no difference. Shutting off the preamp while the amp is on sends a spike to the amp.  Depending upon the amp's design, it may shut down, or make a scary loud pop sound.  My NuForce amp and preamp used to give me a scare once in a while.  That is when I learned to stay with a "soft off" that left the preamp in standby.
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