Does anybody really know what makes turntables hum?

[Ixnay]

So I set up a normal turntable with a normal (Fidelity Research) tone arm and a normal cartridge and normal cables. And the turntable hums like nuts, way more than one can ignore. I mean, I bought all this normal stuff because I wanted to get rid of hum.

And nobody really knows anything about this, do they?

 

[Purité Audio]

Usually a grounding issue, does your tonearm cable have an earth wire?
Keith

 

[Ixnay]

Yes. Connecting it makes a small difference.

 

[Purité Audio]

The hum is through the speakers rather than a transformer?
Keith

 

[Galliardist]

You'll need to post full details of this "normal" equipment, up to and including the amplification and how things are plugged in for power. With sufficient information I'm sure someone can help you.

Alternatively, it might be that the poor turntable is humming because it doesn't know the words.

 

[Ixnay]

Here's something: If I grasp the tone arm between my thumb and forefinger the hum recedes to an ignorable level. I'd love to hear one of you slide-rulers explain that to me.

Always somebody wants to hear "full details of this "normal" equipment, up to and including the amplification and how things are plugged in for power". Like grounding principles are different if there's a different name on the nameplate. I think that they're really just voyeurs who want to hear all the details so they can

 

[Ixnay]

The hum is through the speakers rather than a transformer?
Keith

Transformers don't get that loud.

 

[sergeauckland]

Here's something: If I grasp the tone arm between my thumb and forefinger the hum recedes to an ignorable level. I'd love to hear one of you slide-rulers explain that to me.

It's very clearly a grounding issue. By touching the tone arm, you're grounding it. You need to check the grounding of the tonearm through the wiring, also check the grounding of the cartridge body, as with some cartridges that's grounded to one of the cartridge pins. Then also check that the arm ground wire and any turntable metalwork grounding, which may be separate to the arm grounding.

I know grounding issues with turntables to be a bugger to fix, but they are almost always caused by a broken connection or perversely, too many connections causing a ground loop. You'll just have to work through them. A continuity meter or buzzer will be a great help.

S

 

[Ixnay]

I get what you're saying but how am I a ground when I'm floating around in space?

I don't have a wire wrapped around my ankle and going to a stake in the ground somewhere...

 

[SIY]

I get what you're saying but how am I a ground when I'm floating around in space?

Unless you're an astronaut, you're not floating. Listen to Serge.

 

[solderdude]

you need to check if there is an electrical connection between the tonearm and the groundwire.
That groundwire should be connected to a special screw on the back of the amp or the metal casing of the amp or on the RCA shield.
This will only do something when the tone arm and ground wire are actually connected.

 

[fpitas]

I get what you're saying but how am I a ground when I'm floating around in space?

I don't have a wire wrapped around my ankle and going to a stake in the ground somewhere...

You're a capacitor to the Earth.

 

[JayGilb]

You're a capacitor to the Earth.

A touch lamp works on that principle.

 

[fpitas]

A touch lamp works on that principle.

Us slide-rulers know that kind of thing

 

[xaviescacs]

I get what you're saying but how am I a ground when I'm floating around in space?

Don't listen to this people, according to general relativity we are all floating, not just astronauts.

 

[Joachim Herbert]

Slides rule the world. Unfortunately.

 

[Purité Audio]

Slide rules are cool, never knew how they worked but cool nevertheless.
Keith

 

[computer-audiophile]

When I was still young in my profession, it was customary for us to wear a clean white coat in the lab. A slide rule visible in the breast pocket. The first 'pocket calculator' I was given was a Compucorp, as big and heavy as a brick. Many years later, HP pocket calculators came into fashion as a status symbol.

 

[Deleted member 21219]

When I was still young in my profession, it was customary for us to wear a clean white coat in the lab. A slide rule in the breast pocket. The first 'pocket calculator' I was given was a Compucorp, as big and heavy as a brick. Many years later, HP pocket calculators came into fashion as a status symbol.

I gotcha beat. When I went to school, we got our daily issue of fresh clay and a clean stylus. Not only that, but our textbooks were unbelievably heavy (the phrase "chiseled in stone" comes to mind).

Jim

 

[fpitas]

When I was a boy, logarithms were made from real logs!