2. amps-preamps
  3. 131736-78740

Pre amp ruining analog

I recently obtained an Audio Research Ref 6 which works wonderfully well for digital but creates such a whine and hum when I try using it for vinyl I can no longer listen to it. I've spent a lot of money on my analog set up and enjoy vinyl enormously so you can imagine how frustrating this can be.

I've tried all the known remedies; cheater plugs. grounding from the tone arm to all components, unplugging my cable box and wireless router(which of course cannot be a long term solution), using different inputs, switched rca and balanced interconnects... I don't have a lot of room in my apartment so I can't go moving components far away from each other. I could go back to ss but I'd prefer to keep the arc because digitally it creates such beautiful music compared to the ss pre I had before. And it would be a hassle to sell needless to say.

My amp is a vtl s200(shortly switching to a Pass 350.8) which created a slight hum for vinyl which was masked by the music but the tube pre makes lps intolerable. My phono pre and head amps are allnics(when replaced with a Shiite the hum was still there. When I had a ss pre amp and amp the allnics created no hum at all.)  Turntable is a vpi superscout with 3D tonearm and koetsu blue lace.

Any ideas before I am forced to go back fully to ss? Tubes are so musical and warm but they seems to come at too high a price.
vindanpar
lostbears's avatar
lostbears
538 posts
 

 That was a long time ago when ARC gear was mostly single ended. There was sometimes a ground loop between the amp and preamp. ARC recommended grounding the preamp and floating the amp.

 Are using balanced or single ended cables from the  phono preamp to the Ref 6?


roberjerman
4,319 posts
 
Your Allnic tube pre-pre amp is the likely culprit. Get a good step-up transformer!    Any tube gain stage will be inherently noisy when trying to amplify a mc cartridge's typically low voltage (<1 millivolt). Yet the mc cartridge has adequate current output - making it an ideal match for a transformer! I have been using step-up transformers with my mc cartridges for 40 years with NO problems! Perfectly quiet backgrounds to the music from LP's! I'm presently using a Denon 320 with a Denon 103R. Since you have a Koetsu you might consider a Koetsu step-up transformer (after selling the Allnic!) Or for less money a Bob's CineMag would be a good choice! Check out Art Dudley's writings on this subject on the Stereophile site (under "Listening") He believes (as I do!) that NOTHING beats a good mc cartridge and transformer! That is why I have always preferred analog over digital playback!
roberjerman
4,319 posts
 
I have yet to hear an active gain-stage that can equal a passive transformer's quiet backgrounds AND dynamic contrasts when used with a mc cartridge!
atmasphere's avatar
atmasphere
12,198 posts
 
A whine is often caused by a microphonic tube.

But this problem only shows up on the phono input, and as I recall all the Ref series preamps are line stages. So the problem sounds like a microphonic tube in the Allnic.

Try swapping the interconnect cables left for right at the input of the ARC for the phono. If the problem moves, the ARC is off the hook and the Allnic is suspect. I'd be tapping the tubes to see if the whine shuts up even for a little bit.
More to discover