2. amps-preamps
  3. 1375199393

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
georgehifi's avatar
georgehifi
10,312 posts
 
Ok you tried to give all 4 preamps a earth with no joy, but you have not said if the mains lead on them is earthed?, if so disconect it, if this still is not a fix, "luckily you can still enjoy music running source-direct." which in your case is a good impedance match and you still have an abundace of gain.

Cheers George
yingtonggao OP
71 posts
 
Finally got a noise-free pre/pwr combo! Audio Mirror T-61 preamp + Cary 300SE monoblocks. I don't know why but this combo is free of noise/buzz/hiss. Sounds wonderful too! The best I've heard with Avantgarde Duo.

Substituting either pre or pwr with another brand and the noise comes back.

Unfortunately Cary discontinued the 300SE. Does anybody know the sonic difference between 300SE and 300SEI?
charles1dad's avatar
charles1dad
10,250 posts
 
Active tube pre with 300b SET, you`re good to go. Congratulations with solving the problem.Now just enjoy your music.
response34's avatar
response34
169 posts
 
There may not be much difference in the circuitry between the SE and SEI but with the SE being mono blocs and the SEI being an integrated, my guess would be the SE monos would sound better as they don't share a power supply or chassis. The other advantage (if you want to call it that) is that you can choose your own preamp when working with power amplifiers vs integrated amps.
georgehifi's avatar
georgehifi
10,312 posts
 
Yingtonggao looks like high system gain may have be your problem with the other setup.
This is what Stereophile said about the measurements on the Carys, looks like they have very low gain. Which is what's needed for a very efficent horn system.

"Input impedance was an easy 150k ohms in parallel with around 100 picofarads.
The amplifier needed a fair input voltage despite its modest output power"

With their very high input impedance of 150kohms they are also begging to have the DP-777 directly into them.

Cheers George
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