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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
stereo5's avatar
stereo5
6,539 posts
 
Hence, a reason why I will not own a Rega.  Too many hum complaints.
lewm
13,536 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.
sumadoggie's avatar
sumadoggie OP
62 posts
 
While I don't have a frequency meter, and don't know if it's 60 or 120, it's certainly a hum tone.  

Should the wall outlet screw be grounded?  There are Faraday cages on Amazon in which the Aria would fit and when slightly modified the cables could be accommodated.  While cutting a hole for cables isn't ideal, perhaps that's a way to go.  

I did order some isolating fabric which arrives today.  I'll update the thread with my findings.  
sumadoggie's avatar
sumadoggie OP
62 posts
 
By the way, there is a "grounding post" on the back of the Aria.  Is this just there if the Aria is used with a different TT to prevent a ground loop, or can this post be used to help ground the Aria itself?
millercarbon's avatar
millercarbon
12,531 posts
 
Thanks for the DM. One key to preventing hum is having only one path to ground that is the same for everything. The Aria is already connected to ground via its power cord. So you connect the turntable to the ground on the Aria, and nothing else connects to that ground unless its another turntable. 

If the integrated is between the turntable and the phono stage then the phono lead has to go past it and there's a small chance it picks up hum along the way. Fooling around with phono lead routing is always a good idea. You can sometimes hear noises come and go while you're moving it, touching it, etc.  

Also, fields coming out of the integrated aren't necessarily equal in all directions, nor is the phono stage equally shielded from all directions. So there's always the chance that above it picks up noise, below it doesn't. Tracking these things down is my least favorite thing about phono, and explains why if you ever hear my system as totally to die for awesome as it sounds when playing music it would drive some guys absolutely crazy when its not. My standard is if the noise level is only about as much as groove noise then you call it good enough and get onto something else. You'll get there. 
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