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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
glai
glai's avatar
glai OP
446 posts
 
The noise is louder with phono cable plugged into the ASR and quieter without the phono input plugged in at all. However, there is still noise with the phonostage connected to the preamp. I tried orienting the IC differently and did result in marked decrease in noise (awkward equip position_. Would this indicate RF is in the air?

The ASR is battery powered. Why are some phono more sensitive to RF than others, are there RF filters or shileding available?
markd51
763 posts
 
Unsure if those little Ferrite RFI Filters that clip onto an IC would be of help?

One thing you could possibly try, is connecting a ground wire from the Chassis of the Phono Stage to Pre, or even perhaps too, a ground wire from Pre to Main Amp?

The only other things that come to mind here, is trying different Interconnects, but you might have tried this already? That, and perhaps another Pre-Amp? Can someone borrow you one to try?

I'm certainly no electronics guru, and I'm just drawing straws here, but the only logical answers I have is to go through every component associated with, and go through the process of elimination. Mark
glai's avatar
glai OP
446 posts
 
I tried the grounding the phono and preamp wiht no improvement. Tried Valhalla, Cardas GOld Ref and Signal Cable, no significant difference there.
swampwalker's avatar
swampwalker
5,138 posts
 
IYou said it decreased when you re-oriented the IC. s the IC running parallel to any AC cables, or near any transformers or power supplys in your equipment?
skytop's avatar
skytop
48 posts
 
Be certain to use balanced cable with your balanced equipment.Have proper grounding.Also, use of noise reduction equipment (distribution/ power conditioning) can also be very helpful.
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