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
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
4,456 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?
calgarian5355 OP
146 posts
 
Jea48...
I'm in the midst of re-wiring my entire system (moving components around) so I'll give your suggestion a try in the next couple days. My preamp is the Copland CVA306 six channel tube preamp; my amplifier is the YBA 2 Alpha High Current. The preamp does not have a mute switch.

I somehow doubt that it's an amp problem though. I was previously using the amp with my Rotel pre-processor (now sold) and it did not have that problem.

Tony
calgarian5355 OP
146 posts
 
Thanks to everyone who responded. I bought the receptacle tester and everything seems to be wired properly. I realized that the volume was not turned all the way down before powering up my equipment. With the volume knob turned all the way down, combined with waiting 10 - 15 seconds after turning on the preamp, there is now a very minor push-pull effect on the speakers when I turn the amp on...much less than before!

Again, thanks for all your great advice!
Tony
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