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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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tinear123
241 posts
 
Many tube amp designs shunt the outputs during shut-down.  Some amps will see this as a shorting of the input.
arsh
367 posts
 
 I definitely agree with what some of the other folks have said here about operational sequence.  I always try to remember this about my main amplifier: “last on, first off. “
 
 I switch on everything else first and wait until it is fully powered on and only then turn on my main amplifier. When I’m done listening I switch the main amplifier off first before I switch off the other gear. 

 I hope this helps. 
bdp24's avatar
bdp24
9,734 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.
n80
2,116 posts
 
Thanks guys. Small correction to my post: When pushing the standby button on the amp to the standby position there is a tiny pop from the speakers and a click within the amp. Turning the pre-amp off first (I don't do it anymore) makes a loud pop in the speakers.
imhififan's avatar
imhififan
2,176 posts
 
It’s pretty easy to accidentally turn off the preamp when I’m leaving the 509X on all the time.
My suggestion is use a IR remote controlled plug/outlet for the CL40 valve preamp and a remote control with macro, program a set of command sequence to turn off the CL40 valve preamp:
Mute the L-509X, change the input out of HT bypass, power OFF the remote controlled plug/outlet for the CL40 valve preamp.
To turn on the CL40 valve preamp:
Mute the L-509X, change the input out of HT bypass, power ON the remote controlled plug/outlet for the CL40 valve preamp, change the input to HT bypass, un-mute.
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