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
Yes, I did try preamp-less and preamped options between the DP-777 and Cary 300SE. I prefer the preamped sound, being more ripe, full-bodied, and solid. In comparison the preamp-less sounds a little cardboardy and less 3D, the difference is not as prominent as in some system though, but I consistantly find a good active preamp helpful in various systems (I've bought and sold hundreds on audiogon). Last night I invited a cellist friend to my home and we listened to various cello/string pieces, he confirmed that the preamped sound is closer to a real cello.

George, you are right the Cary is a low-gain amp and it certainly helps to reduce system noise in this case! But a good active preamp is the soul of a system and many people can't live without it. Nelson Pass has a point, but other designers at Conrad Johnson, Audio Research, Supratek, etc are not dumb either.

I should mention that Audio Mirror's T-61 tube preamp is a tiny little wonder for ~$1K. It replaced a trusty CJ Premier 14 tube preamp as well as an Audia Flight Pre SS preamp in my system. It's innovative in using LED (instead of a resistor) to ground the tube circuitry.
The findings of your musician friend comes as no surprise to me or others. When the full body, tone, color saturation and dynamics are preserved the sound is more realistic and live like. This is confirmed repeatedly when listening to live music. Components that are incapable of delivering this vital (and obvious) musical information are deficient. The complaint that passive or direct can sound lean, thinner and less dynamic is subtraction of information from the audio signal it would seem. If a good active preamp avoids this flaw that would be desirable.
Charles,
"being more ripe, full-bodied, and solid. I've bought and sold hundreds on audiogon."

All preamps sound different,Yingtonggao this is why you've bought hundreds?? they do not all sound like straight wire with gain (uncoloured) otherwise they would all sound the same and there would have been no reason for you to buy hundreds.
As they are all coloured in some way and not true to the sound of the source you are looking to find the colouration you prefer. Just these two statements of yours have basically said to me just that.

Cheers George

they do not all sound like straight wire with gain (uncoloured) otherwise they would all sound the same and there would have been no reason for you to buy hundreds

Pretty much any component in one's rig has a sound of its own, i.e. is "colored". This includes also the cables, which you keep on bring up as your reference. Can you be more specific and tell us which brand of wires are you talking about?