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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
clio09
3,355 posts
 
It's virutes are transparency and lack of coloration. It's shortcomings are timbre and dynamics but you have to spend perhaps 10X or more $ to substantially improve on the LSA.

I would say I can agree if the second half of your statement was attributed to passive preamps (a well designed TVC the exception) in general. I find in my system the LSA does not lack in timbre and dynamics. For reference I use the LSA with the Music Reference RM-10. My other system is Atma-Sphere MP-3 and S-30 amp. Sources are the same for either as are speakers. I could live with either of these amp/pre combinations, one costing about 5x less as the other. Sure there are differences in the sound, but they are much more similar than different. Ironically I found a combination of the LSA and S-30 to be less satisfying, although still enjoyable. It tided me over just fine while I waited on my MP-3.
whart's avatar
whart
3,039 posts
 
The original purpose of the thread was to discuss noise abatement using a very high efficiency speaker (one which I own). George, I have great respect for what you do, but I think the proselytizing is a bit much since many of us have a variety of experiences using different sorts of set-ups, passive and active. I'm not sure this is the place to debate the merits of passive preamps.
And I say this without being condescending. I just recognize that there are many ways to get to the end result, which is music.
No disrespect intended, either to you or to Mr. Pass.
atmasphere's avatar
atmasphere
11,817 posts
 
George's Lightspeed is IMO one of the best PVCs made, but-

If then you don't like this, by all means colour it to your liking with a active preamp of your choice, this is why ALL active preamps sound different as they are not a strait wire with gain, as Nelson Pass alludes to in his statement. And if other can't see this they cannot see the forest through the trees and believe in voodoo.

this quote is rendered entirely fictitious by the last sentence. IME PVCs usually have more coloration, not less, than a competent line section (although as I have pointed out in the past it is because the math of the situation goes against you when trying to use an outboard PVC, Nelson Pass or no; I am sure if he ran the math he would come to a similar conclusion). Try running 30 feet of cable between the PVC and the amps and you will see what I mean.

I find that the better a line stage is, the more they sound like real music.

Now if you really want to make a PVC work, the thing to do is install it in the amplifier so you don't have the math issues associated with the cable.

Don_s, you were correct- I meant 'without'.
grannyring's avatar
grannyring
6,484 posts
 
An isolation transformer can indeed fix or sort out the noise issue mentioned by the poster. I have used them with good results.

Yes, the LS passive attenuator is easily one of the best buys in audio history. It does sound very nice and if I had a very low budget it would be high on my list. Both Charles and I are talking about best in class active tube preamps that cost many times more.

I, like Charles, simply wish George would stop saying we like Voodoo etc..That simple.

I also thank George for his unselfish DIY giving. I am a very active DIY guy and kind folks like George make it possible for me to play.
clio09
3,355 posts
 
The OP is going to have a hard time sorting out the noise issue with 104 dB speakers. I do not think line conditioners or isolation transformers are going to solve the issue. He has already said going direct with his CD player has worked. Maybe this is the solution. Based on this if he feels he needs to insert something in between I would have to recommend something that will not add gain. I would recommend either the LSA or a very good TVC (Bent Audio and Music First come to mind), and if there is a need to increase flexibility to have longer cables or to have peace of mind regarding impedance matching then something like the Pass B1 or Burson Audio buffer could work. An MP-3 set up as a tube buffer could work as well.
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