2. analog
  3. 156664-112802

Phono stage hum - Rega Aria

Hi folks, trying to solve a hum issue and would appreciate any thoughts. Rega Aria phono stage, into a PrimaLuna Dialogue tube preamp, then to Bel Canto SS mono's. 

With the tonearm NOT plugged into the phono stage, there's a hum.(especially when set to MC vs. MM)
Rega powered off, no hum while preamp at max volume. Turn the phono stage on, there's the hum...I hold the phono stage in the air, 4 feet from everything, same hum. When I hover it over my preamp, the hum gets much louder due to interference. Magnaplanar 1.7i speakers very quiet until that phono stage enters the chain.

Haven't tried a cheater plug...but have tried 2 diff interconnects (Better Cables/Silver Serpent and BJC LC1) from the phono stage to the PrimaLuna, and 2 different power cables (Furutech FP-S022N and factory cable) into a Furman Elite 15-DMi. 

Either this Rega Aria is a noisy phono stage, or I've somehow got a ground loop in there with it. It's really not bad at lower volumes, but sucks when that hum breaks the silence at louder volumes between songs/sides. 
Opinion - is this phono stage a weak link in my system? Maybe it would be fine if I find a way to eliminate that hum. 

JA Michell Gyro TT
Rega RB 808 tonearm
Ortofon Cadenza Black cart
Primaluna Dialogue Premium preamp
Rega Aria phono stage
Bel Canto M500 mono amps
Furman Elite 15-DMi power
Magnaplanar 1.7i

Better Cables/Silver Serpent interconnects
Blue Jean Cables for phono and Maggies
Furutech FP-S022N power/outlet

Cheers, thanks for any advice! 
128x128malmc02
malmc02's avatar
malmc02 OP
30 posts
 
Tonearm plugged into the phone stage = hum. Tonearm disconnected from phono stage = hum. Cheater plug added to power cord for phono stage = hum. Cheater plug added to power cord for preamp = hum. Connected the tonearm ground wire to the ground of the phone stage. (Phono stage manual recommends that) = hum.  Grounded phono stage to ground of a few other pieces = hum. 
RCA out from the preamp feeds a powered sub. Disconnected that cable from the input on the back of the sub just now, for giggles. Accidentally touched that rca tip to a screw/ground on the back of the sub (other end is still connected to the preamp rca out) and the hum essentially stopped. LOL
gordon
127 posts
 
With everything connected, try moving the phono cable around, ideally away from other interconnects and power cords.
malmc02's avatar
malmc02 OP
30 posts
 
Hi Gordon, I’ve tried multiple phono to preamp cables moving them around, and lifting the phono stage in the air, away from everything...= hum. 
malmc02's avatar
malmc02 OP
30 posts
 
Everything was powered by the Furman...so I just ran a 50’ extension cord from the preamp to an outlet in the kitchen. Hum still there.

The fact that the hum went away when grounding the tip of an RCA, while the other end is plugged into an output on the preamp is strange. 

@millercarbon I know from reading your posts for quite a while now that you’ll have some theory about this gremlin. ;) It’s quite vexing. 
hagtech
163 posts
 
You've got magnetic coupling into the phonostage.  Will get worse when you add TT.  Check proximity to a power transformer in another piece of equipment.  You will need to space things out... 
More to discover