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Thinking of a new preamp and looking for advice...

So, I am currently running a BAT VK30 into a Parasound A21 to Golden Ear Triton 2 speakers.  Sources are a Sony Z1ES and a Linn LP12 to a Parasound JC3+ phono stage. Green Audioquest cables all around. Most of my listening is vinyl--lots of jazz and 70's-80's rock and female vocals. I love the sound of my system, but the BAT is very finicky about power, and I have a ground loop that I cannot find...It works fine at other locations, but has a hum in only the right channel in my listening room...It's driving me bananas!

I demoed a Sonic Frontiers LS1 and the ground loop was gone, but it didn't have the open airy sound that my BAT does.  I am looking into an Audio Research LS-27, and also a McIntosh C47.  My must haves for a new preamp are at least 2 balanced inputs and balanced outs, and a remote control.  I may like to stay with tubes, but I'm not opposed to SS either.  Price-wise my ceiling is around $4000.  I would love to here from anyone who has either of these preamps as to what they like or don't like about them.  I am also open to suggestions. 

Thanks for your input.

128x128jptenberg1
minorl
1,016 posts
 

I have REF 3 for sale at this time.  I'm the original owner and you would love it.  look me up on AudioGon

As far as the ground loop is concerned.  Have you tried the tried and true procedure to find it?

1. Connecting the speakers to the amp only. removing all connections and interconnects, except speaker cables.  Noise?  yes, it is the amp.  No, move on

2.  Connect the pre-amp only to the amp to the speakers.  noise?  yes.  it is the pre-amp or the cables from the pre-amp. 

and so on one element at a time till you find the source.

jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
1) I have unplugged all sources from the preamp and it goes away.

2) cleeds

Good suggestion. I just tried it with my iPod. Iplugged it into a SE input and the hum was not there.


I think this is all the proof you need to know that the BAT VK30 is not the problem, as well as VK’s assurances.

I went through this 20 years ago with a Cary preamp (my 1st tube preamp). I sent it back to Cary twice, and both times they found nothing wrong with it. I eventually gave up and went back to a SS preamp (Classe?).
SS preamps are less susceptible to ground loop hums, but IMHO, they are less susceptible to musical nuances.
I cannot live without a tube preamp anymore, though occasionally I have to fight through a grounding issue.

I’m rather surprised to hear that you tried Jensen ground loop isolators on RCA and XLR audio inputs, as I was thinking of the video device.

http://www.jensen-transformers.com/videos/

Do you have no video cable in your home/apartment?
If you do, try simply unplugging the cable input, and see if the hum goes away.
It makes no difference if the video system is on a different circuit, or in a different room.
tango_tilingo
47 posts
 

Hi jptenberg1  I know your price ceiling  as you describe it, but I will share with you briefly

my journey into this crazy hubby. I start it with a Kenwood receiver, move to a separate

power and pre amp it was a David Haffler. I change the pre-amp to Ps Audio 4 after that

I try most of the major brands from MC, Mark Levinson, Pass Lab, Cary Audio, SLP-98 and SLP-05, and final one was the Audio Research LS 27. My search ended when I try the Merrill Audio Christine Reference Pre- amp, it will take your system to the next lever. Merrill has a 30 days try, he is a very nice to deal with, good luck  Juan.        

atmasphere's avatar
atmasphere
11,834 posts
 
I'm not convinced this is a ground loop. If that were the case, lifting the ground connections (I assume at the power cords; please correct me if I'm wrong) would have solved it.

Do you have a Digital Volt Meter (DVM)? If so, some simple measurements can put the ground loop issue to bed. On the Ohms scale, with the equipment unplugged, measure from the ground pin of the power cord to pin 1 of the XLR. What is the reading? Is it the same as the ground of the RCA connection? I would do this for the preamp and amp for starters.

BTW we make a tube preamp called the MP-3 that is fully balanced, has dual outputs and 3 balanced inputs (one of which is phono if the preamp is optioned with a phono section, which is also balanced). You might be able to find a used one or a demo at your price point.
dragon_vibe
430 posts
 
I was just about to Recommend the MP-3 Pre-amp from Atma but it seems Ralph is already suggesting it.  I have both the MP-3 and MP-1.
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