Do I need double earths?

[Phil Lawton]

Just turned on just the amp and Primare and got the earth buzz, without the turntable being switched on.

[Phil Lawton]

It would appear the Clearaudio Concept Signature turntable uses an external 12V power supply. How is this connected to the mains?

It’s a wall wart mains connector.

[Barry]

Connect the separate earth lead to the Primare R32 phono stage, using the ground terminal. If the hum problem persists, then you could try connecting the earth lead to the ground terminal on your Marantz amplifier.

If you still have a hum problem, we will have to look at the turntable's external power supply (unlikely) and to the cartridge/tonearm interface.

[Phil Lawton]

Connect the separate earth lead to the Primare R32 phono stage, using the ground terminal. If the hum problem persists, then you could try connecting the earth lead to the ground terminal on your Marantz amplifier.

If you still have a hum problem, we will have to look at the turntable's external power supply (unlikely) and to the cartridge/tonearm interface.

Will do…means moving the Primare up a level, so I’ll try this on the morrow.

Thanks for all of this, Barry.

[Barry]

Just turned on just the amp and Primare and got the earth buzz, without the turntable being switched on.

That clears the wall wart power supply, which being a DC power supply was not a prime suspect.

We will see if there is any improvement in changing the arm earth lead to the ground terminal on the Marantz amplifier.

[CageyH]

What happens if you disconnect the earth lead from the turn table to the R32?

[Steph Dale]

To be honest, that's probably where I would have started. Some cartridges, cables and/or tonearms have odd earthing arrangements and this would check that the loop/hum isn't due to a parallel earth between the cartridge/arm/turntable and the amp.

Steph

[Barry]

The Concept V2 cartridge uses a metal housing. If this housing is connected to the 'cold' connecting pins of either of the two channels, and the separate arm earth lead is also used, then an earth loop would be formed. But it is not at all obvious if the metal cartridge housing is connected to the signal earth.

[Phil Lawton]

That clears the wall wart power supply, which being a DC power supply was not a prime suspect.

We will see if there is any improvement in changing the arm earth lead to the ground terminal on the Marantz amplifier.

Barry

You were bang on…Clearaudio now attached to the amp’s earth and buzz eliminated.

Many thanks for your help.

[Lawrence001]

Barry

You were bang on…Clearaudio now attached to the amp’s earth and buzz eliminated.

Many thanks for your help.

Isn't this the standard set up for a TT to try first? I've always done this (well except where I have a separate phono stage, when I use that - maybe that was the issue here, I should really read the above first [emoji23]).