Is it possible to try a different outlet without the extension cord?
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.
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.
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- 58 posts total
Lowrider, I had previously suggested trying the CDP’s stock power cord on the preamp. However, given that it is now evident that the CDP’s stock power cord doesn’t fully eliminate the problem when used on the CDP, what I would suggest is that you try connecting the CDP with the Audience power cord in series with the long extension cable (which eliminated the problem when plugged into a distant outlet), plugged into the **SAME** AC socket you normally use for the CDP. And if that resolves the problem but also results in any adverse sonic effects, try putting the extension cord in series with the preamp’s power cord instead, plugging it into the same place as usual. Keep in mind that when you eliminated the problem by connecting the CDP to the distant outlet you changed two things at once, namely using the distant outlet, and putting the extension cable and its undoubtedly significant inductance in series with the CDP’s power cord. At this point we don’t know which of those variables eliminated the problem, but it very conceivably could be either of them (or both). Best regards, -- Al |
@jea48 Check again for resistance from the ground pin on the power cord plug to the metal chassis of the amp. "OL"?Yes, OL (or zero L). Maybe a code for something? Next measure from the ground pin on the plug to one of the outer grounds of one of the RCA jacks on the back of the amp. (No ICs connected to the inputs of the amp.) Any resistance?1.0 for resistance. I have looked on Carver/Sunfire forums for a schematic and no luck. Others are asking for them and apparently the company has never released them to the public. Many thanks for interest thus far. |
If you do not measure 000.0 or in otherwards "short", or continuity, then for some reason the metal chassis of the amp is floating above the safety equipment ground. That does not meet any equipment electrical safety standards/requirements. What is odd though, from your measurements, the safety equipment grounding conductor of the power cord is connected to the signal ground. You measured 1 ohm of resistance. Correct? That’s basically "short". Have you ever removed the top cover from the amp before? If you can remove the top cover,. then look at the back where the power cord enters the back panel. Look for the green equipment ground wire of the power. Is the wire broken free from the metal chassis? It should connect directly to the metal chassis. One other test measurement I should have had you check. From what you have said thus far the result should already be known. I still would like to have you check. Check for continuity from the outer contact of one of the RCA input jacks to the metal chassis. It technically should read "short", "000.0", continuity. But from what you have said from the measurements you have taken, you should read "OL" open circuit. The signal ground is not connected to the metal chassis. IF the chassis if floating above the signal ground as well as the safety equipment I would think that could cause buzz/hum problems. And then there is the coupling capacitance leakage of the primary to secondary winding to consider. Is this what your amp looks like?
I assume you have the jumpers installed in XLR female connectors. |
- 58 posts total