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Why do my speakers "POP" when I turn off preamp?

HI. Is there any way I can get rid of that loud POP sound though my speakers that I get when I turn off the preamp (and leave the amp on)? My preamp is a C-J PV10A, which is recommended to turn off when not in use, but my amp is the C-J MF-2200, which is SS and can be left on. That sound can't be good for the speakers.
dawgcatching
tbg
5,263 posts
 
Amplifiers amplify! Why would you want your amp to strengthen the sound of the power supply of your preamp collapsing? Next you will be telling us that you cannot pick up your lawnmover with it running and not cut off your fingers.
jeffreybehr's avatar
jeffreybehr
805 posts
 
To Jea48, that won't do any good because the turn-off (and -on, too) transient is created by the line stage, and that's always in the circuit full volume no matter where the selector switch or volume control is set.

"Next you will be telling us that you cannot pick up your lawnmover with it running and not cut off your fingers."
Just who is 'you', Thg? There are a dozen people above you.
.
jea48
2,944 posts
 
Jeffreybehr, It was just a thought. What you said makes since why it won`t work. I`m no tech, but let me throw another one out there. If the preamp has at least two sets of rca outputs, if the spare set were shunted just before he turned off the preamp. Volume control set at minimum. Or instead of a total shunt install a load resistor. Would this cause any damage to his preamp. If it would do the job and not cause any damage to his preamp, he could take a cheap pair of ics cut off one end and install a simple momontary 2p n/o contact push button. He would press and hold the button, turn off the preamp, continue holding the button for say two or three seconds. Would this work?

Guys, as for wanting to leave his SS power amp on all the time, a lot of audiophiles do.
morbius396c
134 posts
 
Jea48,

The input impedance to an amp is quite high. Therefore, it
doesn't take much signal for the amp to see it.

If you install a shunt - or even if you try to short the
output - that shunt or short is still in parallel with the
amplifier input. [ Any "short" you place on the terminals
still has a finite resistance - so it's not a true short. ]

Even though most of the "signal" current from the shutdown
transient is sent through the shunt - a tiny amount still
finds its way to ground through the amps input stage.

Result - problem not solved.

The only safe solution here is to shutdown the amp.

Dr.Gregory Greenman
Physicist
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