2. amps-preamps
  3. 1143525327

Which to turn on first...Amp or preamp?

Hoping someone can help me out. I have a tube preamp and solid state amp. I'm very new to tube equipment and have discovered that regardless of which unit I turn on first, be it the amp or the preamp, there is always some "electrical noise" from the speakers when I turn the second device on. If I turn the amp on first, followed by the preamp, I hear a slight buzz (I'm assuming this is the tubes warming up...?) followed by a low frequency noise that makes the woofers on my speakers push out and pull back to a large degree. If I reverse the order of turning the equipment on, I no longer hear the buzz, but the speakers still display the push/pull effect. This never occurred with my solid state preamp. Two questions....Is this normal? ...and....If it is normal, which unit should I be turning on first to do the least amount of damage to my speakers or equipment?

Any advice would be appreciated!
Tony
calgarian5355
vicdamone
850 posts
 
I had a similar issue with my large electric Bass rig which consists of a solid state power amp, a hybrid preamp, sub crossover, etc. Plugging the AC cables into a modified (10g wire and Hospital grade receptacles) switched power strip eliminated the problem.

Sol322's suggestion should be done regardless of weather it fixes the problem or not. A simple three light receptacle tester should do the job.

calgarian5355 OP
146 posts
 
Thanks to everyone who responded.
My equipment is currently being plugged into an Audio Magic Eclipse power conditioner. I'm not an expert at electrical testing, but with the test that Sol322 is suggesting, what am I looking for? Would this test indicate if the power receptacle was wired incorrectly? I'll see if I can find one of the 3 light testers at Home Depot this week. Aball...Yes, the push/pull effect occurs even when the volume is turned all the way down.

Tony
charlie101
57 posts
 
Mitch4t
According to Joe Fratus at Art Audio, you can leave the solid state amps powered up while powering down your preamp; it's good to engage an unused input before powering down. You need to follow the first on/last off if you run all tubes he says. Solid state can remain powered up but it helps if you are able to place the amps in standby mode when possible.
stevecham
3,340 posts
 
It has been well stated by my esteemed colleagues above, but another way to approach this is:

When powering up, work your way from source to end of the audio chain (speakers). Start tuning on at the beginning of the signal chain, i.e., the source (CD, tuner, phono pre) and then power on in the direction the signal will follow (the preamp next) and finally the last in the electronic chain (the amp).

When powering down, work your way back from the destination (speakers) to the source (next the preamp) and then the sources.

Power on from beginning to end.
Power off from end to beginning.
jea48
4,456 posts
 
If your tube preamp has a mute switch make sure to switch it to mute before turning the preamp off.
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Turn on any input equipment you will be using, CDP, ect.

When you turn on the preamp leave the switch in mute, then turn on the power amp. Wait about 20 to 30 seconds then set the mute switch to normal.
===

When shutting the system down, again first mute the preamp, then shut off the power amp , and then the preamp.

Last any input equipment, CDP, ect.

See if that helps.
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I assume you always turn the volume control down before starting shut down.
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