Noise from phono. Help please.


Recently became an analog fan and currently experimenting with different phono stages (ASR basis excl., ARC Ph7 and ayre p5xe.) System includes Avid Acutus, triplanar arm which comes with RCA connectors and ground wire. ARC ref3 preamp, VAC amp and Avalon speakers. System is quiet with cds but when a phono was added, noise became an issue.

The Ayre is very quiet and there is very faint background noise that is not audible at 8-10ft from speakers. (Vahalla XLR to ARC preamp) IC position doesnot change noise level.

ARC ph7 has some noise (buzz, hum). It is audible when no music is playing but when music is playing it is not an issue. What is strange is that when I change the position of the interconnect (single ended Cardas) connecting the phono to pre, the amplitude of the noise increase and decrease markedly. The PH7 is quieter at my friend's system in a dedicated circuit.

Noise is loudest with the ASR, amplitude varies with the positioning of the phono cable, interconnect. Interestingly, when I was leaning over the ASR phono, noise also decreased. Noise is present even when the tonearm is unplugged from the phono. Noise doesnot change with shunyata hydra in or out. I used to have a Hovland preamp which had a low level hum which completely went away when RF filter was installed by Hovland.

Guys, please advise me on how to reduce hum/buzz.

1) IS this due to RF from the powerlines (needs dedicated circuit ) or is it from RF in the air?

2) How can I shield RF in the air?

3) Is the RF picked up in the tonearm cable, phono stage or interconnect? I assume that the main culprit is the IC and possibly the phonostage because when tonearm cable is unplugged, noise is still there?

4) Is grounding issue involved?

thanks in advance
128x128glai

Showing 1 response by steveaustin

I've driven myself batty chasing down the same gremlins in the past. I DO know that basing your noise level "frame of reference" on what you hear when your pre-amp is set to "CD" when comparing phono noise levels is a recipe for total frustration. The fact that you are dealing with the low-level phono signal, AND have tubes in the circuit almost demands you learn to tune out some low-level noise as you do with vinyl surface noice and just "enjoy the music", as they say. Want to really frustrate yourself, though? Add a step up transformer to the mix, and then spend hours trying to find the position where it causes the least amount of added 'hum'. AAArrrgh!
My latest OCD phono fixation? The motor noise I can hear from my 'table between tracks in a quiet room. Can I hear it when the music is playing? Of course not. Does that stop me from obsessing over how to get rid of it? No way, Jose' - just the idea that it's there really bothers me.

Audiophilia nervosa.

I do look forward to the responses from some of the other, more knowledgable A-goners to the good question you've posed, and good luck.