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.
on my system i turn off the power amp first and that stops the pop from making it to your speakers,you can allways turn your power amp back on after you turn off your preamp,,
Bad Kharma......no possible reason to leave the amp on.

Rule is....amp(s) on last, off first. Practice this before you damage the speakers.


Paul :-)
I always take my volume down to zero when I finish a listening session, just to play it safe.
Dawgcatching, does your preamp have a mute switch? Try setting it in the mute position first before you turn off the preamp.
Turn off your amp first and then your preamp!
Turn on your Preamp on first and then turn on your amp.
Okay, thanks! I was following C-J's manual and it said I could leave the amp on 24/7, but that I should turn off the preamp when not in use, which extends the life of the tubes. Guess that isn't a good idea in this case! After the first time it happened, I started turning the amp off first, but thought there was something I was missing (I don't have a mute button, and the volume control does nothing in this case).
I've had three CJ based pre-amp/amp systems and always turned off amp first (they were all tube designs) and waited about 1-2 min then turned off pre. If you turn off pre but leave amp on you're allowing some voltage to leak into speakers which causes popping sound - not a good thing.

When you shutdown your preamp - it's circuitry goes through
a "shutdown transient". That is as it loses power, the
circuitry goes through a type of "death throw".

Some amps and preamps have a "muting circuit" to disconnect
the output before the transient. Yours evidently doesn't have
that circuit.

You should always power up your equipment in the direction of
signal flow - source components on first, then preamp, then
finaly power amp.

When you shutdown your system - the order is reversed - the
power amps should be shutdown first. So if you follow
the proper shutdown order - the power amps should already
be shutdown when you turn off the preamp - so the shutdown
transient won't damage the speakers.

Note - the power down transient of the preamp may not be
suppressed by the volume control - depends on the preamp
design. So you can't depend on a volume control to save
your speakers.

As Paul suggests, learn / practice proper startup / shutdown
proceedures before you damage your speakers.

Dr. Gregory Greenman
Here is something to throw out there. If his preamp has a selector switch for different line inputs, and he installed shorting RCA connectors in one set of line inputs and turned the selector switch to this input before he turned the preamp off, would it shunt out the transients? Anybody, Ideas??? Would this work?
He would like to be able to leave his SS amp on all the time.
Follow up, rca shorting connectors would have to be install on the tape inputs. Switch set to source for normal operation, tape to shunt. Would this work??
Follow up follow up, tape input is still infront of that darn volume control.

When C-J wrote your manuals, perhaps they were assuming that
your C-J tube preamp would be paired with a tube power amp,
and that your SS power amp would be paired with a SS preamp.

That way, your tube power amp would be powered down [ to
extend tube life ], when you powered down your tube preamp.

In the latter case, your SS power amp would remain on with
the SS preamp.

Mixing tube and solid state components can be problematical,
depending on the design - although the marriage of the two
technologies can have a positive effect - exploiting the
advantages of both.

For example, tube preamps will usually have a greater
amount of DC voltage on their outputs. That's OK with
tube power amps which are capacitively coupled. However,
many transistor power amps are "direct coupled" - no
coupling capacitors in the signal path - thus expecting a
very low DC component from the upstream SS preamp.

If the upstream preamp is tubed, and the power amp is a
"direct coupled" SS - there can be problems - which can
easily be remedied by installing coupling capacitors.

Moral to the story - you just have to be aware of the
various characteristics of the components you link together,
for proper "care and feeding" of your stereo components.

Dr. Gregory Greenman
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.
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.
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.

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