Question abouit signal grounds and connections from a TV ?

[Peter Stockwell]

I just installed a new Mains cable arrangement in my system, I believe the overall noise floor of the system has dropped considerably.

My question:

I have a 4m attenuated interconnect between the TV and the Preamp. The TV has 2 wire mains input, i.e. no earth (I imagine it's double insulated ?).

I haven't tried disconnecting yet, but I was wondering if the 4 metre interconnect would be polluting the ground plane of the preamp, even when the TV is off ?

If it was I was wondering if some kind of transformer connection would be better ?, or even a A/D converter, they can be had cheaply, and going through an optical of my DAC.

Any thoughts on the subject ?

[Ali Tait]

Is this going to an amp or preamp? You could fit an earth lift resistor to the signal ground inside the amp/pre. How you do this depends on how the signal ground is connected inside, i.e. are the rca sockets insulated from the chassis?

[Peter Stockwell]

Is this going to an amp or preamp? You could fit an earth lift resistor to the signal ground inside the amp/pre. How you do this depends on how the signal ground is connected inside, i.e. are the rca sockets insulated from the chassis?

Come to think of it I think the preamp has a ground lift switch, The preamp is an implementation of the tentlabs volume control, i've asked the same question of the builder.

[Ali Tait]

Ok sounds like it's sorted then. If not, you'd just need to fit a resistor from the rca socket grounds where the i/c from the telly connects to. 100 ohm will do.