Phono hum

Silly question, but have you checked your earth cable (from the arm) is connected to an earthing terminal on your phono amp? Might be also worth checking the earth connection is correct in the mains plug, assuming you are confident?

Peter,

Please  try your P75III into the 52's Tuner input and see if your hum disappears?

The 52 Phono input has internal phono boards attached- connecting an additional phono pre ( your P75III) would certainly cause some issues... If the Tuner input works well , then use it, Imo, the P75III is a better phono than the 52's internal boards . If you are up to it, open the 52 casework and see if the phono boards are installed? Good luck !

Atb,

Mark

Have you moved anything?

I had this with rega TT and Elys cartridge i had to move the phono amp a good way from the TT and that well away from the main amp.

Initially there was lots of hum because the cartridge was picking up hum because it was too close to the transformer of the amp. ( It was at least 12 inches away)

Good luck

I have had hum issues with my TT. Generally moving everything away from the tonearm that I could and making sure power cords only crossed signal cables if they had to and at a 90 angle. 

Thanks for your suggestions. I'll certainly check things with your points in mind.

Mark - your suggestion makes sense, but I don't currently have a phono to din cable. My cables are phono. I may have something in the back of a cupboard somewhere.

I'll have another go tomorrow (well, later today technically) and get back to you.

Peter

Do you run a separate earth from the back of the turntable to the P75? On my Amadeus it was essential into the P75 to avoid a hum.

Pedro,

Did you replace the phono boards in your 52 with "straight through" boards? Definitely worth looking inside the case imo. If you have a set of phono boards  inside the case  and you run your P75 through the Phono input, you are essentially running TWO phono stages! Take a look inside....

ATB,

Mark

Hi Peter,

if you are running a third party phono stage into a Naim pre- or integrated amp, which I do as well, connect the ground wire from the arm to the preamp and run a second one from the preamp to your phono stage. This setup made things noticeably quieter in my system.

Mulberry-Do you run your third party phono stage into the "loaded" Phono input of your Naim pre-amp as well?

If Pedro has straight through boards installed in his 52's phono section then maybe an earthing problem is the culprit. If he has "N", "S" or "K" boards installed and is connecting an additional DV P75 to this input , then THIS is the problem !

Open the case and look inside...

Hi Varyat,

I sure hope Peter is not doing this. On the other hand, if he does, discarding the Dynavector phono or using a line level input on his 52 would be pretty easy solutions.

My phono stage is connected to the Aux 1 input on a Supernait, just as intended .

Exactly! Peter's original post clearly states that he is connecting his DV P75 into the PHONO input of his 52- hence my question regarding the phono boards. An easy mistake to make because the phono boards are tucked inside and out of site... All that needs to be done is getting a phono/Din cable and connecting his P75 into  the Tuner input, or Aux as you have done. If he still has a hum problem, then it is likey a grounding issue, RF from his P75, cartridge tags......etc.

ATB,

Mark

Have just tried the suggestions made earlier. I did find a cable that enabled me to use the aux input. The buzzing was there. Not so when using the tuner. I've attended to the cable dressing issues and the improvements made no difference. Still buzzing.

I originally used the P75 in to the phono inputs on my 52 and there was never a buzzing issue. The buzzing started recently. So something has changed.......it suggests a fault now that the cable dressing has been attended to. As it worked fine for quite some time, then I think it reasonable to assume there are no internal phono boards.

My thanks to all who have made suggestions.

I'll perhaps refine the cable dressing further. As for the earthing cable from the turntable. This was hooked up to the earth on the back of the 52. I did try attaching it to the same on the P75. This made no difference.

Peter

Peter, I'm clutching at straws a bit here but when I owned a DV P75 mkIII, it had its own wall socket as did the record player. The rest of the system was powered from a WW Matrix2 from a third socket. My Linn's arm was earthed to the back of the P75. Might be worth a try.

Chris

Thanks Chris. Will try this evening. I did change sockets recently, so will revisit the plus and where they plug in.

Peter

Thanks. RCA to DIN i/c from the back of your P75 mkIII into an unused DIN on the back of the NAC obviously.

C.

I recently had some work done to my LP12 and when I got it home I had a hum. I removed the earth cable that is connected to my phono stage and all was well. It was probably caused due to a better earth to the chassis after a Circus bearing upgrade. Since then I have removed the Valhalla power supply and fitted a Lingo3 and now all is back to normal with earth lead reconnected. So I would remove the cable and see if that cures it. 

Thank you all for your ideas and suggestions. The hum stubbornly refuses to go away. I just removed the earth cable from the back of the 52, but this didn't result in a reduction in the hum.  I removed the tuner, but can't think of anything that's different between now and before the problem arose.

Before re contacting my dealer, I plan to disconnect and re-connect the entire system again. Off to listen to Nut Rocker again......

Peter

I had this problem with a superline. Connecting the Earth on the phono amp with that on the pre (mostly) sorted it