Humming

[Peter D]

I have an Audio technica turntable with line outs and an earth lead. The system works with powered speakers (Azatom equinox) but there is no where to connect the earth lead to the speakers. How to do I get rid of the humming when activating the turntable with stylus arm? Can I earth another way and still use the powered speakers to avoid the humming?

 

[nopiano]

Welcome to the forum, Peter.

I had never heard of Azatom but I found their website and your speakers. What I can not tell from the pictures is if the connecting panel at the back is metal. I suspect it’s plastic, can you confirm?

The workaround would be to connect the earth/ground lead from your turntable to one of the screws. Otherwise, rewire the turntable earth to the screen of one of the phono plugs.

You should not have to do this, but I’m guessing you bought everything by mail order so have no dealer to help? With the volume set just loud enough to hear the hum, you can safely use the earth lead to touch metal bits on the back of the speaker to hear if that stops the hum. Obviously, don’t try to stick in the mains socket!

PS. What does Azatom customer support recommend?

 

[Al ears]

Welcome to the forum, Peter.

I had never heard of Azatom but I found their website and your speakers. What I can not tell from the pictures is if the connecting panel at the back is metal. I suspect it’s plastic, can you confirm?

The workaround would be to connect the earth/ground lead from your turntable to one of the screws. Otherwise, rewire the turntable earth to the screen of one of the phono plugs.

You should not have to do this, but I’m guessing you bought everything by mail order so have no dealer to help? With the volume set just loud enough to hear the hum, you can safely use the earth lead to touch metal bits on the back of the speaker to hear if that stops the hum. Obviously, don’t try to stick in the mains socket!

PS. What does Azatom customer support recommend?

funnily enough, if the OP is in the UK , I was going to suggest extending the earth wire to the earth terminal within the plug....
Or buy a Rega turntable.

 

[Peter D]

Yes, the back of the speaker is plastic. I’ve tried contacts on the back of the speaker but none of these work. I’m still waiting for Azatom to get back to me.

I had thought of using an amp just to earth?

 

[nopiano]

Yes, the back of the speaker is plastic. I’ve tried contacts on the back of the speaker but none of these work. I’m still waiting for Azatom to get back to me.

I had thought of using an amp just to earth?

But they’re powered speakers*, so that’s not really the answer. Can you return them and get separates?

* they have their own amp inside

 

[nopiano]

I’m not recommending this exactly, but in my shop days I’d have wedged the earth wire behind the screen/outer part of the RCA phono plug of one channel where it attaches to the speakers.

Try touching the earth there. Don’t unplug the phono plug with the speaker powered as that’ll make a hell of a buzz. Just offer up the tip of the earth to the metal bit you can see.

 

[Al ears]

I’m not recommending this exactly, but in my shop days I’d have wedged the earth wire behind the screen/outer part of the RCA phono plug of one channel where it attaches to the speakers.

Try touching the earth there. Don’t unplug the phono plug with the speaker powered as that’ll make a hell of a buzz. Just offer up the tip of the earth to the metal bit you can see.

Surely if the speakers are powered there must be an earth somewhere that can be tapped into.

 

[Friesiansam]

Surely if the speakers are powered there must be an earth somewhere that can be tapped into.

Not if they are double insulated and have a 2 conductor mains lead.

 

[Peter D]

That is the problem. There is no earth contact. None of the existing contact points work.

 

[Peter D]

Where to put the earth?

 

[Gray]

Where to put the earth?

Have you tried holding that spade connector on the outer body of one of the 'line 2' sockets.
That will effectively be doing what Nopiano suggested in post #6.

 

[Peter D]

Yes unfortunately that makes no difference.

 

[Gray]

Yes unfortunately that makes no difference.

Move to plan B for the next CAREFUL experiment - as hinted at by Al in post #3.
Assuming you've got 3-pin UK mains sockets - If you've got a spare mains extension lead, before plugging it in, wedge that spade connector into the exposed EARTH terminal on its socket, then plug the extension lead in.
If you don't know which is the earth terminal, DON'T DO IT.

 

[Peter D]

Where you say wedge into exposed earth terminal on socket (of extension lead) you mean underneath socket extension
May be one of 2, 3 or 4 ?

 

[Peter D]

Move to plan B for the next CAREFUL experiment - as hinted at by Al in post #3.
Assuming you've got 3-pin UK mains sockets - If you've got a spare mains extension lead, before plugging it in, wedge that spade connector into the exposed EARTH terminal on its socket, then plug the extension lead in.
If you don't know which is the earth terminal, DON'T DO IT.

 

[Gray]

Where you say wedge into exposed earth terminal on socket (of extension lead) you mean underneath socket extension
May be one of 2, 3 or 4 ?

Imagine a 4-way trailing extension socket with nothing plugged into it.
On each socket, the top, exposed terminal is the earth. All 4 of those are connected together, so it doesn't matter which of those you use - no need for a plug to be in any of the sockets.
It must be an earth - if you've got any doubts, don't even try it - it could be the last thing you do.

 

[nopiano]

Yes unfortunately that makes no difference.

I suspect that is because when 1 is selected to hear your source, 2 is disconnected. Hence my suggestion about trapping the wire under the shield.

 

[Friesiansam]

You could try something similar to what I do with the wire on my anti-static wristband. One end is connected to the wristband, or in your case the turntable. The other end is fitted with a small crocodile clip, this holds an earth-pin from a mains plug and, can be plugged straight in to a standard wall socket, completely safely.

 

[Gray]

You could try something similar to what I do with the wire on my anti-static wristband. One end is connected to the wristband, or in your case the turntable. The other end is fitted with a small crocodile clip, this holds an earth-pin from a mains plug and, can be plugged straight in to a standard wall socket, completely safely.

Yes, if it cures his hum he could just buy a mains plug - the type where you can easily remove the pins....and either remove and use the earth pin or remove the live and neutral pins, for a neater look.

 

[Al ears]

Not if they are double insulated and have a 2 conductor mains lead.

true

 

[Al ears]

Yes, if it cures his hum he could just buy a mains plug - the type where you can easily remove the pins....and either remove and use the earth pin or remove the live and neutral pins, for a neater look.

That's what I would do if necessary

 

[Gray]

I suspect that is because when 1 is selected to hear your source, 2 is disconnected. Hence my suggestion about trapping the wire under the shield.

Certainly worth a try before moving to the mains earth option.
I suspect that lines 1 & 2 grounds are permanently connected, but you never know.

 

[Peter D]

Imagine a 4-way trailing extension socket with nothing plugged into it.
On each socket, the top, exposed terminal is the earth. All 4 of those are connected together, so it doesn't matter which of those you use - no need for a plug to be in any of the sockets.
It must be an earth - if you've got any doubts, don't even try it - it could be the last thing you do.

Yes that has worked, humming only very feint.

 

[Peter D]

Yes that has worked, humming only very feint.

 

[Al ears]

Yes that has worked, humming only very feint.

Good to hear.
How close are those speakers to the turntable itself?