Question about adding a DI input to a 500 series preamp

[JAY X]

Hi!

I plan to add a DI input ( that i have to design and build), to an already made 500 series preamp. Luckily, I could connect the DI balanced output to the balanced input at the pcb board edge small through hole pads.

As far as the incoming signal to the preamp comes from either the 500 rack rear input OR the front panel DI, (when a guitar is connected), there should not be any problem...¿Right?.
(because the output of the DI will be permanently soldered to the input edge connectors at the pcb).

So, this is my question: will the output of the DI (without any signal), interfere with the balanced input by any means, just because it is soldered at the board edge?? I think it should not... but i prefer to ask before messing...

Jay x

 

[chilidawg]

You could use a switched jack connector with a simple transistor logic to turn on/off a signal relay to bypass your DI circuit when an instrument plug is not inserted, or when a plug is inserted, the rear balanced input is bypassed, and your DI output signal takes over its place going into the preamp.