extension of wires on turntable

[plippert]

Hi all,
I am beginning to feel really really dumb.
I have bought a Rega Planar 3, and it is working like a charm. The turntable is places approx. 6 meters from my amp, an old harman/kardon with RIAA, and I have made an extension-cable for the turntable, but no matter what I do, there is a loud humming sound. From the turntable there is two phonos and a seperate ground-cable. From this I have made an extension with female phonos and seperate ground -> female DIN. The DIN is connected with the + connected to the connector called 3 and 5. The - in from the signals and the seperate ground connecte to leg called 2.
From the female DIN there is a male DIN connected the exact same way -> male phono with the seperate ground connected to the ground-connecter on the amp...

Alright. This annoying humming is loud, and I can't seem to get it to disappear. However, when the two female-phonos touch each other, the humming becomes less loud.

Can someone please help me with a few pointers on how to make an extension cable for a turntable that actually works? Links to where I can buy new parts is much appreciated (if necessary)...

Merry x-mas to all and thanks in advance.


Peter

[tvrgeek]

Sorry Peter, but that is a bad idea for the reasons you are experiencing and others. You need the amp as close to the cartridge as possible, the cables as low of capacitance as possible. (If you fixed the hum, you will find your high end rolled off). You are dealing with tiny voltages and current.

Your best bet is to get or build a phono stage suitable for your cartridge and put it right at the table with short wires. I have an old NAD I use as I don't have a high end table any more. Might look for the first generation Hafler kit, it had a very good phono stage.

[plippert]

I was afraid, that it would not be possible
So the correct setup is:
Turntable->phono stage->6 meters extension->amp?

Thanks
Peter

[tvrgeek]

Yup.

[pski]

Originally Posted by plippert

Hi all,
I am beginning to feel really really dumb.
I have bought a Rega Planar 3, and it is working like a charm. The turntable is places approx. 6 meters from my amp, an old harman/kardon with RIAA, and I have made an extension-cable for the turntable, but no matter what I do, there is a loud humming sound. From the turntable there is two phonos and a seperate ground-cable. From this I have made an extension with female phonos and seperate ground -> female DIN. The DIN is connected with the + connected to the connector called 3 and 5. The - in from the signals and the seperate ground connecte to leg called 2.
From the female DIN there is a male DIN connected the exact same way -> male phono with the seperate ground connected to the ground-connecter on the amp...

Alright. This annoying humming is loud, and I can't seem to get it to disappear. However, when the two female-phonos touch each other, the humming becomes less loud.

Can someone please help me with a few pointers on how to make an extension cable for a turntable that actually works? Links to where I can buy new parts is much appreciated (if necessary)...

Merry x-mas to all and thanks in advance.


Peter

It could be possible that the two AC devices are on different circuits making the "ground" connection invalid.

It could also be that the signal from the turntable to the pre-amp is near another AC cable and the cable is not well insulated.

[tvrgeek]

pski,
Both may be true, but still just aggravating a basically untenable situation; that of a very low power source trying to drive too much load.

[pski]

Originally Posted by tvrgeek

pski,
Both may be true, but still just aggravating a basically untenable situation; that of a very low power source trying to drive too much load.

Try the simple first