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Please help me eliminate my phono section hum

I have a Well Tempered Classic V turntable, with the carbon-fiber arm, using with an Audio-Technica ATML170 high output moving magnet cartrige, going to a Balanced Audio Tech. P5 tube phono stage, then passing this signal to a Reference Line passive preamp.

The connections from the phono stage to the passive are XLR, the phono stage is plugged into my PS Audio P300 AC conditioner,, which has it's own completely isolated AC line. There are no florescent lights in the room.

I have TONS of gain, but cannot eliminate a persistant tizzy buzz (it's not the cheap wine either!)

The turntable has a ground line from the RCA output block going to earth ground as does the phono stage and even the passive pre.

I would like to upgrade to a high output MC cartridge but am afraid it would only exacerbate the problem.

Help! Anyone?
denf
dogpile
118 posts
 

Hi Denf.

The first thing I would check in this instance are the tubes in the phono pre. Try lightly tapping on each with a pencil and listen closely taking notes.

OR / AND

If the buzz is in one channel only, switch the tubes from right > left and hear if the buzz follows.

OR /AND

If buzz is coming out of both speakers, swap each one to locate the noisy tube.

Check back with your findings and all the best!!

Hy :D
elevick
2,638 posts
 
Try eliminating all of the grounds, then hooking them up one at a time?
denf OP
241 posts
 
Thanks guys - and I will try your recommendation Dogpile. So far though, it seems like it might be the tonearm and/or RCA block at the table itself? Anyone ever heard of a buzz coming from defective tonearm wire??

I'll keep looking...
bdgregory
1,715 posts
 
Denf, I've been having a similar problem and have yet to trace it. I have an Audioquest PT6 and it seems it's highly prone to this hum sound. I've noticed as I change the configuration of my equipment in the rack it can be better or worse, but it's still there. I also found most recently that if I conect a jumper wire connected to the ground post on the table and to the ground on one of the RCA connectors (any one) it helps to reduce the problem. My next step is to get a new tone arm cable (ie from the DIN connector on the arm, to the pre), and see if that solve it. After that I'll either try to hat new internal wiring in the arm, or just get a new arm. I've tried everthing else. I'm watching this thread carefully to see if anyone comes up with a simpler solution, as I posted a similar thread a while ago and there were no simple fixes provided.

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