Turntable concerns...

nooshinjohn

I am having a ground issue with my table and a difficult time in tracking the source. I am using an Origin Live Conqueror MkIII 9 inch arm, ClearAudio Goldfinger Statement V2 cartridge, and Analysis Plus Phono cable.

When the table is in use, I get a very loud hum, and when I touch it, the hum gets louder and there can even be a discharge similar to static electricity. The table sits on top of a marble topped entertainment center...

Any ideas what the cause could be?

gp4jesus

Like, as soon as you switch to “Phono,” “hmmmmm.....?”

W/ or w/out the platter spinning?

Are you wearing shoes? On what kind of floor?

Hum get louder wearing gloves? Yeah deep space, but I’m considering all possibilities

Have you tried disconnecting one TT channel or the other?

Does the TT have a separate ground connection? I had a table w/the same.

What have you unplugged or disconnected during “hhhmmm-ing?”

Does anything has a grounded plug?

Is this a 2 ch system only?

txcoastal1

Is it plugged into wall or a common source like a power conditioner

jdjohn

So this came from out of the blue? Like yesterday it was fine, and now this?

spongebobsquarepants

Want your old cartridge back?

mhardy6647

@jdjohn's question is a very good one.

Cables (and, IME, cable connectors) are always suspect when hum of unknown origin pops up. Some judicious swapping is in order.

I'd also disconnect the cables from the tt to the phono preamp and make sure that the problem's upstream of the preamp. It might not be.

In the good old days, reversing the polarity of the AC power cord plug in the mains socket was the first troubleshooting stop for hum issues. I presume that's a nonstarter in this case (polarized two prong or grounded three-prong plug).

Assuming that it is better hum-wise, to have the tt grounded is ... just that (i.e., an assumption). Test the assumption! Try removing the ground and see if hum is better or worse. If more than one ground lead; remove one at a time and check the effect on the hum.

I like to use clipleads to ground components piecemeal and look for changes in hum; for example, a ground lead clipped to a grounded screw on the phono preamp to the preamp itself. Also, I know some tts (like the "Marantz" Clearaudio I have) had two separate ground leads. try moving grounds around, or lifting grounds.

When it comes to power conditioning, regeneration, & stuff -- all bets are off. Strip all of that cr@p out of the power supply, plug stuff into the wall, one component at a time and look for the return of the hum. Remember that a tt will "work" fine (in terms of signal generation) unplugged. The power is only for the motor! Does the tt hum if unplugged under the same conditionsunder which it does when plugged in/turned on?

Hum is often induced. Are there any power transformers/power supplies near the tt? If so, try removing them, or just move them and see if the hum level changes. Turning a P/S or transformer 90 degrees can/should alter inductive coupling substantially (remember there are three dimensions).

Any digital cr@p in the vicinity is always suspect. Unplug or remove any that is nearby & see if it matters. Don't forget SMPS and Class D amplifiers produce tonnes of RF hash; not just DACs, digitial players, and computers/tablets/displays. All of this stuff is of the devil when it comes to analog noise.


FWIW, I suspect the static discharge is a red herring & unrelated to a persistent hum issue. It is wintertime; the humidity is probably extra-low even in @nooshinjohn's neck of the woods.

nooshinjohn

The motor for the table is in a stand-alone unit separate from the table itself, and I have found that if I touch that silver platform that shows in the picture as being part of the arm assembly, and on the same plane as the platter ring, all noise goes away completely. I guess that means there is an isolation issue with the arm.

mhardy6647

clip lead, baby!

are you 100% sure all of the leads in the arm (and the connections at both ends) are A-OK?

jdjohn

Did you recently swap cartridges?

nooshinjohn

problem was there before the swap, and all the leads are good...

displayname

I don't know the science of this, but try touching and wiggling each section of the entire phono chain. See what parts increase, decrease, and make no change in the hum.

I occasionally have some hum creep into my system. I isolated not only to my phonostage, but specifically to the kid. I lightly loosen or tighten the lid screws one at a time. Once I find one reduces the hum, I hone in there. A quarter turn to a full turn in one direction or another cleans it right up.

Sometimes I don't need to touch to for months. Sometimes I need to twice in a month. But it's a very easy fix now that it's been isolated.

And in an older system I would place a book on my amp and it would resolve a similar but less frequent option.

Ground hums and weird, and unfortunately can be inconsistent.

jdjohn

So you had the problem with your original GF, and now also with the GFSV2? I saw where you did a major disassembly of your tt before installing the GFSV2, but it read like you had good results after all that work. What happened next?

nooshinjohn

jdjohn wrote: »

So you had the problem with your original GF, and now also with the GFSV2? I saw where you did a major disassembly of your tt before installing the GFSV2, but it read like you had good results after all that work. What happened next?

The hum has always been present at some level, and gets louder as I turn up the volume, as has the static issue. It is only now that I am turning my attention to it. It is there whether a record is playing or not, so long as phono is selected as the source.

TroyD

I've had a similar issue with my VPI if the motor gets to close to the power supply of the amp or phono stage....

BDT

jdjohn

John, along the lines of what Mark said, you may need to add another ground wire connection, and I would start with one between your phono preamp and line-level preamp. If that doesn't help, try going from phono pre to power amp, or to the power conditioner if you have one. I have to do this with some of my MC carts, but normally only if I have an SUT in the chain. There is no rhyme or reason to it...I just live with it.

Yes, it is frustrating attaching two wires (spade connectors are easier) under one ground lug nut on your phonostage, but we do what we have to when chasing grounding issues. If your line-level preamp, power amp, or power conditioner don't have a ground lug, you can just loosen a chassis screw on the back panel, and slip the connector under that. Of course before you attach it in any way to those units, you should be able to hear the difference (hopefully hum being gone) by simply touching the wire firmly onto the spot.

The wire does NOT need to be fancy in any way, and thinner will be easier to work with. So again, attach one end under your phonostage grounding lug along with the one from your phono cable, and then with the other end, start experimenting with touch points on units further down the chain. Hoping for the best!

mhardy6647

jdjohn wrote: »

...
Yes, it is frustrating attaching two wires (spade connectors are easier) under one ground lug nut on your phonostage, but we do what we have to when chasing grounding issues...

Words to live by.

nooshinjohn

I ran an alligator clip from my tonearm to a negative terminal on one of my amps and the noise completely went away, so I think I am on the right path here. I will move the ground to something else when I get a chance, but for now, I am content...

jdjohn

Your noise floor just dropped! Now you can finally get some good sound out of that setup

Joey_V

Dang
A GFSv2
Very nice