2. amps-preamps
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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
jea48
4,522 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.
mitch4t's avatar
mitch4t
1,611 posts
 
Excellent tip Charlie101, especially to engage an unused input when powering down.

....thanks, mitch
sol322
426 posts
 
Tony:
Yes the test will show you if the polarity is correct in your wall plate and also tell you if you have adequate grounding. I'm not familiar with your Eclipse, took a peek at the audio magic site but couldn't tell if it has LED indicators for polarity and/or grounding as others do. It's important to check this for your equipment and filter to work in a proper way.
calgarian5355 OP
146 posts
 
Sol,
I'm not sure if the Eclipse has an LED indicator. I'll check tonight. I'll get the tester this week and see if it's wired correctly. I know the YBA amp I'm using specifically states that the polarity is important (there's a red dot or indicator at the plug location that shows this). Thanks for your help! I learn something new on Audiogon every day! I'll update this thread when I find out what the outcome is.
Tony
jea48
4,522 posts
 
Tony, Just a thought, try disconnecting the ics from the Power Amp's inputs. Power up the Amp just by itself, with just the speakers connected to it. If the Amp still makes the noise, "push/pull effect", through the speakers then that would indicate the problem is with the Amp.

What is the make and model of the preamp? Does it have a mute switch?

What is the make and model of the SS Amp?
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