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
What's wrong with just using the AMR DP-777 with it's volume control or just use a passive preamp like Lightspeed Attenuator or similar with just a pot in a box, no noise with passive pre's. And as you have such high sensitive speakers you are throwing money away using an active preamp, unless you like the colouration they can give.

Cheers George
Passive volume controls and digital controls offer their own colorations. You are certainly not throwing the money away if the active preamp delivers on its promise. They can be plenty quiet on high efficiency speakers if the system is set up correctly.
Whart and Triode: I may have to go through the lengthy process like yours to eventually get rid of hum/noise. I was thinking about Granite Audio Ground Zero yesterday.

Georgelofi and Atmasphere: There are pluses and minuses using an active preamp, and endless threads/debate about going preamp-less. I am fully aware that in recent years digital front ends have better and better output stages capable of interfacing power amp directly; and before I fix everything I have to live with the AMR DP-777 driving my power amp (Audia Flight 100) directly. But you never know what you are missing, and I've witnessed many times a good active preamp can do wonders to a system.
Ying: Just keep in mind that the Granite Audio thing is not really a total solution, but in some ways a 'band-aid'- and i had mixed results with it; on some system configurations with different amp and preamp it seemed to work better than others. Just sayin'. And, you really need two people to work it successfully- one to throw the various switches (exponential combinations, when you add in what gear you join on the same 'path') and one to listen to results. You also may have to order more of their grounding cables and longer lengths to get it to connect to various components. (and yet another variable is not connecting to some components). I bought mine back in 2007 or so, it is far cheaper than some of the esoteric external grounding solutions available today, but imagine if you are handy, you could come up with a DIY solution. ( Ralph or Almarg might chime in here), you may be fighting potential grounding problems within the components themselves. None of this is easy, but it's more labor than anything to get it sorted.
Let us know what you come up with. I hate hum!
Yingtonggao, just read this quote from Nelson Pass, I think we could all aggree that we all here with our combind wisdom pale into insignificance compared to him. Remember your FL100 takes 1.4v input to clip. Your AMR DP777 gives out more than 2v and you have 104dB sensitive speakers.

A Quote from the master Nelson Pass

We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.

Cheers George