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Rega Planar 10/Aria MC Phono Stage HUM

Hey all. I recently took delivery of a Rega Planar 10 and Aria Phono Stage. Hooked it up yesterday. Result: pretty significant MC hum. I’ve done some interwebbing on the matter and have seen the P8/Aria post at this forum, and see that the Aria seems to hum quite a bit. Most of the suggestions about fixing the issue are directed towards checking for grounding issues, etc. The rest of my system is fairly straightforward (Hegel H160 integrated; Hegel CDP4A; top shelf Supra wire) so after hooking it all up, I unhooked everything except the Aria to the amp and the speakers. Same hum, same volume. I did typical ground checks and that doesn’t seem to be the issue. I took the Aria and put it one more shelf away from the amp (as far away as the cable allows) and lo and behold the hum volume was cut in half. While at the new position, the hum would be "tolerable" at any particular music volume, it’s annoying when there’s no music signal going to the speakers. Standard light background white noise is somewhat expected, extraneous signal hum doesn’t work for me. So, if, indeed, this is a simple proximity issue (I don’t feel like buying more wire and putting the Aria across the room), is there an elegant shielding solution for the Aria? Is this an issue of Aria design (possibly an engineering "compromise" as Roy Gandy might suggest)? What are other phono stages at a similar price point ($1500ish) which perform musically as well as the Aria? I see I see the Parasound JC3 Jr might be an option. Looking forward to suggestions. Thanks!
sumadoggie

Showing 5 responses by lewm

lewm
13,476 posts
 
Lady Macbeth never heard of Shout.  It would have done wonders for her guilt complex.
lewm
13,476 posts
 
Balanced operation might help, but if the Aria circuit is not balanced internally, you will not get the benefit of balanced operation. It takes more than an XLR input and three conductor cables to have balanced operation. For that matter, the amplifier may not be a true balanced circuit. You would know that.
lewm
13,476 posts
 
Is it ERS cloth?  You may need to wrap the component completely so that no part of the chassis is uncovered, and then ground the cloth.  A true metal cage is better in this case if only because it allows for cooling.
Before you get that crazy, try using a cheater plug on the Aria, so that it is not grounded to the mains.  As long as you have interconnects plugged in, the unit will still be grounded via the ground of the ICs.
lewm
13,476 posts
 
If what you have with the Aria is truly "hum", then I am beginning to doubt it's due to EMI, but your story certainly is consistent with airborne interference, which usually is EMI or RFI.  Except you've now revealed that you had no hum with your old turntable and phono cartridge.  The problem arose when you substituted one Rega TT for another.  Was the Aria situated as close to your integrated amp back then, as it is now?  If so, the information about re-positioning the Aria in your room having solved the problem to some degree, is out the window.  And I am getting more convinced the problem is or was due to grounding. Either your components are grounded to two or more different nodes, such that ground in one case is a few volts different from ground in another case (a ground loop, in other words), or something just isn't properly grounded.

But have we all been through a a time warp in the last 24 hours since your OP?  You say now that you upgraded the Aria to a Luxman (which is indeed an excellent unit) and your problem is solved.  When did you go out and buy the Luxman?
And yes, the ground lug on the back of the Aria certainly is for grounding. Millercarbon mentioned that the Aria should be grounded to house AC ground via its power cord, but that assumes you are using an IEC standard, 3-conductor power cord and that your electrical outlets are properly grounded.  If you have an older home, that isn't always a valid assumption.
lewm
13,476 posts
 
"Hum" is generally used to refer to a 60Hz or 120Hz pure tone. Do you really have hum or what is more loosely defined as "buzz", which is a mixture of frequencies?

Assuming this really is EMI and not a grounding problem, a Faraday cage may work, but by definition, a Faraday cage must totally surround the shielded component and be grounded. That would make it impossible or awkward to access the controls on the Rega preamplifier. If just putting the Rega on top of a shielding material works, that’s great, but it’s not a Faraday cage. Maybe easier to open up the chassis and install a shield inside, once you figure out the source. Anyway, I think this is a solvable problem and not a reason to discard the unit if you otherwise like it.
Or, if the amplifier can be shown to be the source of EMI that disturbs the Rega, it might be more practical to shield the amplifier, since you don't have to fiddle with it all the time.
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