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Preamp Noise with High-Efficiency Speakers

I have Avantgarde Duo Classic Speakers, I hear a very audible buzzing noise whenever I insert an analog preamp. If I run my DAC (AMR DP-777) directly into power amp, the noise disappears. I have tried 4 different preamps (tube and SS), 3 different amps, a bunch of RCA and XLR interconnects, the problem persists. I have tried dedicated power line and two power conditioners (with Multi-wave options) and various high-quality power cords, so far nothing works, and I am forced to run DAC-direct into power amp. The buzz is not very loud but certainly audible enough to be annoying. There's no noise running the same equipment and power source into regular speakers, I am pretty sure it's just the Avantgarde (104dB sensitivity). Please share your solution if you have had similar situations. Thanks!
yingtonggao
grannyring's avatar
grannyring
4,637 posts
 
George, no need to be shattered. The source you use or anyone uses is not perfect so fidelity to the source is not the goal. The end result of the music out of the speaker is.

An isolation transformer can and has in my experience removed ground related noise that no other method would. Sometimes this happens with certain gear - that is this unwanted noise. I had a noise issue that I could not get rid of until I used an isolation transformer.
georgehifi's avatar
georgehifi
4,966 posts
 

He has tried all that and more.

Quote from the OP:
whenever I insert an analog preamp. If I run my DAC (AMR DP-777) directly into power amp, the noise disappears. I have tried 4 different preamps (tube and SS), 3 different amps, a bunch of RCA and XLR interconnects, the problem persists. I have tried dedicated power line and two power conditioners (with Multi-wave options) and various high-quality power cords, so far nothing works, and I am forced to run DAC-direct into power amp.

Cheers George
grannyring's avatar
grannyring
4,637 posts
 
An isolation transformer from Jensen it different from what he has tried.
georgehifi's avatar
georgehifi
4,966 posts
 
He has way too much system gain, and with speakers that are 104db! He shouldn't have to use an isolation transformer if that would work at all with the problem he has.

Cheers George
grannyring's avatar
grannyring
4,637 posts
 
I agree. He should have to use it. I liked the sound of a past system and the
only way I could keep,same components was to use a Jensen ISO tranny.

It rid the system of a buzz I could not tame in any other manner. Not ideal
as you say, but it worked and did not change my sound. In my case the
issue was between the amp and preamp. It was a buzz.

Just an idea.

The OP can call Jensen as they are very helpful and they can help
determine if this would be a strong potential fix. I bet they would be open to
letting him try and return it if it does not,cure the problem.

Almag here is the one who turned me onto the idea as well as another
Agoner who had the same issue and the Jensen worked wonderfully.

I assume here a nice tube preamp would deliver better sounding music and
this step is thus worth it.
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