Power Amp Noise at very low volumes.

Conradicles

So I just hooked up an Audiosource AMP300 and notice a small amount of noise coming from my tweeters when the volume down or very low.

I heard it in my 2 channel rig and also when I moved the amp into my HT.

Almost possitive it is the amp, because I had a couple of power amps in the past and did not experience this problem.

I heard about the 60HZ Ground noise hum, but I am not sure if that is what is going on. This seems to be a faint buzz coming from the tweeter range.

Please let me know if there is any way to get rid of this via power cords or other means.

Thanks!

ben62670

Dedicated circuit?
BTW you need to come down this weekend:)

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ben62670 wrote: »

Dedicated circuit?

It is plugged into the "High Current" outlet on my power center.

Guess I should plug it into the wall and avoid the power center?

BTW, got my kids this weekend and can't make it.:(
Thanks!

ben62670

I am not a big fan of running amps in a power center. Try an extension cord to a bathroom outlet. They are almost always on their own circuit;)

Conradicles

Thanks Ben.

LessisNevermore

A 60Hz hum won't be coming from the tweeters....if it is, you got real problems.:D

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LessisNevermore wrote: »

A 60Hz hum won't be coming from the tweeters....if it is, you got real problems.:D

Those would be some special tweeters!:)

adam2434

Have you tried a cheater plug?

Also, you could try reducing the input level on the amp a bit.

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adam2434 wrote: »

Have you tried a cheater plug?

Also, you could try reducing the input level on the amp a bit.

The input level seems like a good idea. Currently is is set to the maximum level.

What is a cheater plug?

adam2434

A cheater plug is 3-prong to 2-prong adapter, which can be bought at any hardware store.

I created the same effect by removing the ground prong from some inexpensive Volex power cords.

This a "do at your own risk" thing because it eliminates the safety ground that exists to protect you if the chassis ever becomes energized.

A little more info:
http://electronics.howstuffworks.com/question110.htm

Conradicles

Problem solved. Turned the level on the amp down a tad and plugged into an outlet and not the power center and the noise was gone. Thanks guys.

treitz3

I would think it was more the gain on the amp than the PC. Have you tried plugging the amp back into it to see if it was part of the culprit?

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treitz3 wrote: »

I would think it was more the gain on the amp than the PC. Have you tried plugging the amp back into it to see if it was part of the culprit?

Yes I tried it both ways. I think it was the gain on the amp that made the difference.;) Thanks Tom.

george daniel

Tubes is what you need on those 2B's,,specifically one with EL-34's

adam2434

Glad it worked.

I think it's still worthwhile to try a cheater plug. This may allow you to take the input level back to max without noise.

Also, down the road, if you want to hear a bigger improvement to bass control and overall dynamics, pick up another 300 and run them mono-bridged. This is what I'm doing for my LS90's. Running 2 Amp Three's produces an "effortless" sound with tons of drive. I noticed that using one amp was an improvement over my Pioneer Elite AVR, but two running bridged is a night and day difference. I think I saw refurbed 300's at J&R for under $200. Running 2 of those for $400 would make many very happy vs. the sound they are getting from their run-of-the-mill AVR's.