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AUDIO FORUMS >> General Discussion and Support >> Turntable hum and grounding
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Message started by chromadream on 02/05/23 at 06:16:56

Title: Turntable hum and grounding
Post by chromadream on 02/05/23 at 06:16:56

I just swapped my turntable out for a new one, and now I’m getting hum plus what, for lack of a better description, sounds like audio bubbles. I had this same issue when there was no ground wire on my old VPI, but connecting a ground wire fixed it.

New turntable is an Acoustic Signature Double X Neo, with an AS TA-2000 tone arm. The tonearm has a “tonearm cable,” (DIN), with ground. The supplied cable is an AudioQuest DIN to RCA and has a ground wire. This cable goes to my ZP3, with ground connected (hum/bubbles happening).

The turntable itself has a ground location under the plinth, so I tried that, in addition to the tonearm ground, but still hum and bubbles. I did connect that to the same ground on the ZP3 - that may be the improper way to do it, I have never had to deal with DIN tonearm cables, I have always just had RCA jacks on the back of my turntable.

My questions are - am I doing it wrong for the turntable ground going to the ZP3 ground, where the tonearm ground is also going (2 grounds in same spot)?

If this is incorrect, where should I connect the turntable ground?

Anyone else have a similar issue that you fixed?

Signal path = turntable > ZP3 > ZStage > Taboo Mk IV

All interconnects are Decware, except for the AudioQuest tonearm cable.

Thanks!

Title: Re: Turntable hum and grounding
Post by GroovySauce on 02/05/23 at 13:23:25

Nice table! I just got the Maximus NEO and am blown away at how good it is.

I'm not clear on the "bubble" sound you describe.

What cartridge are you using?

I'm not familiar with the DIN system. Is it possible it's not getting good ground contact?

Take a spare piece of cable/wire and attach it to the ground of the ZP3. Touch the other bare end to a few different points on the tonearm. If it stops or changes there might be an issue with the tonearm cable.

Is the hum/bubbles worse when you disconnect the grounds? If you take a wire and touch both the negative RCAs (outside on the ZP3) to the ground post does that change the hum? Does the hum/bubbles chance when the stylus is on a record? Have you tried rerouting the cable paths?

In the past when I've grounded both the tonearm and table I've run both cables to the ZP3 and it worked well.

Title: Re: Turntable hum and grounding
Post by chapsjon on 02/05/23 at 13:30:20

I don’t have a ZP3, so can’t comment on how well grounding to the ZP3 itself works vs grounding to something else. If you can try another grounding it seems you have little to lose but time. I do know some have so much electrical interference that they ground to a dedicated ground. I have never had to do that, but I think I remember reading about it on this forum RE persistent humming.

Another consideration is your cartridge. Some carts are known to have less shielding and are more susceptible to electrical fields. Grado is a good example. If this is the case, moving equipment around in addition to grounding may help, with the intent to get the cart further away from electrical fields.

Hope that helps.

Title: Re: Turntable hum and grounding
Post by EdwardT on 02/05/23 at 14:51:30

Maybe disconnect the cartridge and have a listen to the cable itself using the ZP3 ground as your reference.

Title: Re: Turntable hum and grounding
Post by chromadream on 02/05/23 at 22:24:06

Thanks everyone for the replies!

I guess the sound is kind of a static sound, not crazy loud. I describe it as “bubbles” because it ebbs and flows, gets worse, gets less worse.

Touching the tonearm with my hand makes it worse, especially on the carbon area of the arm.

Cartridge is Ortofon Black LVB 250….

I removed the Zstage from equation - interference is lessened, until I touch the tonearm.

When I turn off phono stage, no hum/interference.

Swapped turntable power cables, no change.

Swapped tonearm cables, no change.

With tonearm cables unplugged, there is no hum/interference.

Connecting wire to ZP3, and touching tonearm does not do anything, but when I touch the tonearm with my hand, it does get significantly worse.

————————————-

“If you take a wire and touch both the negative RCAs (outside on the ZP3) to the ground post does that change the hum?”

It does not change when I do this.

————————————-

“Does the hum/bubbles chance when the stylus is on a record? Have you tried rerouting the cable paths?”

I don’t really hear it clearly when a record is playing, but I feel like it is buried in there. Whether it is or not, this will bother me because I will always be wondering if it is.

I did rearrange components somewhat, no change, but maybe they didn’t move far enough. I’m done for the day.

I’m actually not too impressed with this table, at least as of right now. It is pretty, I guess, though the platter came with all kinds of gunk on it, even though it was new. I’m coming from a VPI traveler that I had for maybe 9 years….. I would say that the Double X Neo is more resolving, but so far I am trying to justify the cost to sound difference, and it just isn’t there. Hopefully when/if I sort this out I will think differently.

Title: Re: Turntable hum and grounding
Post by LiquidBlue on 02/05/23 at 22:52:01

Have you checked the connections to the back of the cartridge? Make sure the thin wires are not damaged and the leads are properly crimped to have a solid connection to the pins on the cartridge.

Title: Re: Turntable hum and grounding
Post by GroovySauce on 02/06/23 at 13:27:35

What a bummer! This is an odd one. Seems like some sort of grounding issue. I'm don't have any more things to try. I guess call the dealer you bought the table and arm from and see what they say.

Title: Re: Turntable hum and grounding
Post by Crazy Bill the Eel Killer on 02/06/23 at 16:07:32

Years ago when I got my ZP3 it hummed. Same as yours. Touching a tube or anything metal increased the hum. My Sonic Frontiers was dead quiet. Could not sort it out. ( read the thread ZP3: A Humdinger ).
I finally decided to go solid sate and in the process I discovered that the actual ground coming out of the wall was no good. Ran an extension cord from another outlet that tested good and the hum went away.
Check your ground on the outlet.
Good luck, Crazy Bill

Title: Re: Turntable hum and grounding
Post by EdwardT on 02/07/23 at 15:26:32

“ With tonearm cables unplugged, there is no hum/interference”

You've isolated the problem to the tone arm or cartridge, now you have to disconnect the cart to isolate the tone arm.