2. tech-talk
  3. 123848-2280

Isolating Digital Noise, need help.

I'm hearing noise from my ARC CDP thru my speakers presenting as a high frequency "whine" or "soft screeching." I need to isolate my digital from the AC line it shares with my analogue components. Running another dedicated line is not an option at this time.

I was wondering if a power strip with isolated receptacles, such as star-grounding, would be an alternative to a separate AC line.
As a test, I now have the CDP connected to a different outlet in my house and the noise thru my system is eliminated.

Would this type of power strip be an effective solution, and if so, I could use some recommendations. I have several layers of Blue Circle power conditioning, so I would need a strip with surge/EMF/RFI protection.
128x128lowrider57
jond's avatar
jond
5,807 posts
 
lowrider57 you're sure the ARC is the issue? Have you tested other sources just to be sure? And you mention using a cheater plug on the preamp, did you try the cheater before of after you started hearing this noise?
lowrider57's avatar
lowrider57 OP
5,417 posts
 
jond, I've had to use the cheater on the preamp from the beginning due to 60Hz hum. Spoke to Ralph at Atma-Sphere and Almarg and the problem is due to ground loop thru unbalanced cables.
The Jensen Iso-Max didn't work on the preamp, there was still low-level hum and it changed the sonics of the preamp.

The ARC is the issue. No noise when using my backup NAD CDP.
jond's avatar
jond
5,807 posts
 
Gotcha so this noise from the ARC is new or have you heard it combined with the Atma preamp the whole time?
lowrider57's avatar
lowrider57 OP
5,417 posts
 
@jea48, so far there is no high-pitched noise when using the stock PC on the ARC. Perhaps the Audience PC is not a good design for a digital device?

The stock PC sounds pretty good thru my power conditioner, but lacks the open soundstaging and depth of an audiophile PC.
I actually have a Synergistic Research Black PC on order for demo.

Since I'll be adding a DAC, I will still need to isolate digital from analogue components. Is a dedicated line the only way?
Also, I still need to work on the ground-loop problem between amp and preamp, and that will require a separate AC line.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
jond, yes, I’ve heard it the whole time. It took me a while to track down where it was coming from.

I have excellent upper frequency hearing and there has been a constant high-pitched "whine" in my house whenever my system was powered up. I have tinnitus, so at first I thought it was me. I finally put my ear near the tweeter to find it.
More to discover