help with connecting balanced out transformer

[tempus]

Hey all;

I've got a piezo pickup in my electric so that I can get acoustic tones as well. I'm currently sending it through my pedalboard to the PA, but I'd like to add a balanced out. Here's my schem:



Have I got the 150 ohm resistors and caps connected to the right ground, or should they be connected to the centre tap on the 150 side of the tranny, or have I just got the whole thing set up wrong? It seems to me that in the above schem, I'd be opening things up to ground loop hum and negating the use of the tranny, but I'm not sure where else to connect them.

Thanks

[brett]

Hi
usually, you'd want to isolate the two grounds.  The signal is coupled electro-magnetically through the transformer core, and doesn't need a common ground.
The ground on the "left" is the PA ground, and the one on the "right" is the guitar ground.
cheers

[tempus]

Thanks for the reply brett.

Yes I knew that, but where would I connect the ends of the R/C network then?

Thanks

[tempus]

I just had a thought. Would the ground loops still be broken in the above schem since there is no DC connection between the 2 grounds?

[2wm]

isn't "Would the Ground Loops Still Be Broken" an old religious folk song? it should be if it isn't.

[alanlan]

Why do you need the extra components?

The balanced input of the mixing desk will have a lowish input impedance - that's the main reason for using the transformer isn't it? (as well as providing isolation).