Outboard Valhalla ?

[stonedeaf]

I would like to try mounting a Valhalla in a outboard box and seeing if this deals with some of the humm pickup I'm experiencing with a Grado cart on inner groves on my Linn LP-12 ?
Anybody tried this and was there any reduction in humm pickup as a result ? And yes - it probably would be easier/faster/cheaper to go to another cart line that doesn't have this problem - but I do really like the sound of the cheap Grado's !

[analog_sa]

The Valhalla radiates some RF but compared to the motor and wiring it simply has no ability to radiate hum. Whatever benefits you experience from externalising the board, hum reduction probably won't be one of them. Do you love cheap Grados enough to go for a dc motor?

[stonedeaf]

I've looked into the Origin Live DC motor setups - may eventually go that route. But scrounged up what appears to be a brand new Valhalla board that I would like to try out and my very old and heavily modded LP-12 is not a confortable fit for the V board -so will probably outboard it in any case.

[sq225917]

offboard the Valhalla and wrap the motor in Mu-metal, even with my MC cart the effect was a few db reduction in noise at multiples of the mains frequencies, about 3db at 50hz decreasing to about -.3db at 450hz.

Definitely a worthwhile job, and Mu-metal is only about $20 for a 6 inch square sheet.

[stonedeaf]

Since in the best audiophile tradition - I made at least three signifigant changes - not at all sure what worked. BUT - the final result is that I haven't got ANY hum now with the Grado. Here's what i did: substituted 50hz/110 V new motor and pulley for very old 50/60 hz motor with 60 Hz pulley- left switch to fill hole - removed the power cord and the rest of the 60Hz stuff , installed a later Valhalla board (diode mod on board) in a separate chassis with Valhalla power switch. Other than initially getting nothing to work ( had inserted ribbon cable upside down ) - this just got up and ran. The surprise was that for some reason or other - I have NO hum at all now with the Grado Prestige Blue in a Rega RB-600 on this modded LP-12. Previously I was getting low level hum on the inner groves -dead silent now.
Somehow I doubt that this is a result of remoting the Valhalla ( lots of folks would be doing this already if this were really effective) - anybody know if these newer Linn motors have lots less hum field ?
Thanks to Rick at Audio Alternative for coming up with the parts i needed.