Turntable hum.

hey, I hope someone knows about this problem, my turntables are humming pretty bad, it's def not a ground problem, I've doubled checked that, in fact I've been through almost every problem solving process I can think of...

I checked the ground wire, still hums.

changed stylus, still hums.

changed mixer, still hums.

put the turntable on books (don't know what I thought that would achieve) still hums.

unplugged all leads apart from turntables and used my headphones to monitor, still hums.

changed the turntable to mixer phono leads, still hums

Then being a total dime bar I tried the most obvious thing last which is turning off the power to the turntable, NO HUM. The only problem is I obviously can't spin the turntable with my finger while recording into the mpc otherwise my beats would turn out wonky (although I kinda like wonky)

since working out that without power going to the turntable the hum stops I have changed plugs, changed the 8 way adapter and unplugged everything but turntable and mixer but nothing works. If I swith the mixer to line for using traktor scratch or cd's it's absolutely fine, even if the turntables power is on.

I really hope someone can work this out, I'm starting to go crazy.

Thanks an I hope I covered everything haha.

you checked the ground wire, but how?

what is grounded to what? just the TT to the mixer? or also the mixer to an amp or something that's properly grounded?

yeah, It's not a ground wire hum I'm sure of it, If the ground wire isn't grounded to the turntable or my audio 8 soundcard then you hear a really big hum. I'm not even thinking about the amp or speakers, the only thing thats even plugged in is a hak 360 mixer and a vestax pdx, I have my headphones coming out of the hak 360.

I've just remembered that I've got a ground loop isolator/eliminator somewhere so I'm going to go from turntable straight into the eliminator box and out of the eliminator box into the mixer. If that works then I suppose you'd be right in assuming it was a grounding problem. I'm still thinking it's some kind of weird interferance problem from something (but then how if everything else is off?) but I honestly don't know much about electronics so I could be so far from right.

dunno

ThNKAS for the input though.

sorry, I didn't answer part of the question, yes I have also tried grounding the mixer to various things such as an amp, a sound card and a table leg haha. I'm pretty sure mixers don't tend to need grounding though apart from 2 a ttable of course?

depending on the mixer (and its power supply) if the mixer and TT aren't grounded to the same zero voltage level as the amp/monitors then you can get a hum

you can't just ground two things to each other, they need to be grounded to ground i.e. zero voltage

but if you've grounded them to the amp that should be ok (I guess ... I don't know how two-pin electrical systems like in the US are grounded without a third pin for Earth)

are the 4 contacts on the cartridge all fully connected to the correct pin on the tonearm?

cool, thanks for the info, yeah I knew about the zero voltage part. I'm gonna get myself on wikipedia and really get clued up on grounding. by the way I'm also in the uk.

aha! then we can call it earthing not grounding and you have a proper 3-pin mains supply

The turntable hum you speak of, is it like a wobbling sub-bass kind of sound?

I had that too with my first set up, what I did to get rid of it was a couple of things, try these:

- If the turntable has a phono/line switch, then switch it to line.

- Check your speaker wire connection. If the wires are hooked up incorrectly then a hum will be heard. Connect the + of your amp to + of your speaker and the same with -.

- Make sure the table or desk the turntable is planted on is strong and sturdy. Slight vibrations from speakers or a jittering foot can cause hum too. One dude sliced two tennis balls in half and putted them under the turntable to cut the vibration.

Good luck.

hey, Thanks both for trying to help me out with this, you can't imagine how much this has been bugging me, I went as far as to talking my turntables over to a mates house an trying it on his set up and still a hum, even with his brand new carts....

I could only come to the conclusion that it was the turntable motor so I did an experiment to check it out fully. I took a turntable, plugged it in all by itself, (just to the power) no cables or anything and closed all windows an doors so I could really hear it, I then took my sony headphones and my h2 digital mic, put the mic to monitor, switched on the turntable an boom!!! it was humming again. So it HAS to be the turntable motor. By the way I have 3x vestax pdx mk11 ttables which were all bought at diff times.

I'm not an expert on turntables but the fact that the hum only occurs when the power is on and it's louder when the deck is idle (not spinning) makes me think it's the motor kind of in a magnetic stand still phase.

I've had these turntables for quite a while but I've only just started noticing the hum as I have to use headphones these days so everything seems or is more predominant.

Just to REALLY REALLY be satisfied that my conclusion is correct I'm gonna go to my cousins at the weekend with my digi mic and see if I hear the same hum from his 1210's. I very much doubt I will. oh by the way, it;s more just a drone than a wobble, it actually sounds like exactly how you would imagine a turntable motor sounding like if you were ever unfortunate enough to hear one haha.

i have the same problem with one of my technics sl-1210 mk2 turntables (the older one)
but the hummming is very low and i only hear it when the neeedle is on the record with the plate stopped
maybe could be a capacitor or another electronic component that is not working properly or it is not well soldered to the board, i don't know...
i changed the needle, the headshell, the rca cable, the power cable, and the ground cable on this turntable but it's still humming, don't know why
i believe the turntable is about 20 years old (probably more)
so i think it is normal it got some problems
but for the rest it works really well!
i use it every day since 2004

it's very unlikely that it is your motor.

it's a grounding problem within the turntable.

nogginj wrote:it's very unlikely that it is your motor.

it's a grounding problem within the turntable.

well then now I'm really confused because I thought grounding problems were only audible when you had and headphone/speaker output. Can you really hear a grounding problem from a ttable thats not connected to anything.

If thats the case then why if you hook up a turntable to mixer with ground leads but you have your amp turned off can you not hear the ground problem noise?

I know I know that will be the stupidest question ever but I don't care.

eltoppo51 wrote:

nogginj wrote:it's very unlikely that it is your motor.

it's a grounding problem within the turntable.

well then now I'm really confused because I thought grounding problems were only audible when you had and headphone/speaker output. Can you really hear a grounding problem from a ttable thats not connected to anything.

If thats the case then why if you hook up a turntable to mixer with ground leads but you have your amp turned off can you not hear the ground problem noise?

I know I know that will be the stupidest question ever but I don't care.

I meant if thats the case then why if you hook up a turntable to mixer WITHOUT ground leads but you have your amp turned off can you not hear the ground problem noise?

forgive me, maybe i'm misunderstanding.

Particularly this:

plugged it in all by itself, (just to the power) no cables or anything....put the mic to monitor, switched on the turntable an boom!!! it was humming again

Why are you micing the monitor if your turntable is not connected to it?

If your monitors are humming when you flip on another piece of electrical gear, that's only connected through the power supply of the house/apt, i'm at a loss.

Here's where I'm coming from...
- grounding problem within a piece of audio gear / within an audio system of different gear = common.
- humming coming from a speaker when an unconnected, low power device is flipped on = magic.

Ok it's a bit of a stretch to say magic, I don't know much about household power, but I imagine it could easily be a ground loop in the TT screwing up the monitor.

I guess he didn't mean monitor, but motor.

I have another idea: I guess you have heard the vibration of the PU

I dont know how the Vestax are build but you can look for vibration from the power unit.
I had to "modify" my 1210 because the power unit starts to vibrate with the known AC frequency of 50Hz (oh of course, if your in the US its 60Hz). I just loosen the screws of the power unit and put some foam under it. Since my 1210 only stays in its place in the studio its ok. I cant take it with me because of the unscrewd PU. The 50Hz is quiter now but its not completely gone. I guess I have to live with it or buy a new PU or a new 1210 (cant afford it now )

peace