Passive summing mixer build

[Ramshackles]

I'm getting into audio electronics and thought I would start very simple with a passive summing mixer.
I decided on 16 channels on db25 inputs with 10K summing resistors (basically, forsell's passive summing schematic but for 16 channels).

So I've got my breadboard, bits of wire, resistors, db25's and xlr sockets all ready but:
What intrigues me is the thought of putting in 2 1:1 transformers to balance the output...but I can't find much about them or any existing designs with transformers.
How would affect my circuit - are there any transformers I can just put in their without worrying about having to adapt the circuit?

[Matt Syson]

Hi
If it is being 'sourced' from converters or other inputs that are balanced, then the output will also be balanced if you have built it 'correctly'.
You won't 'NEED' transformers and in any case, using transformers with a higher ratio would be beneficial anyway as it would reduce the amount of 'makeup gain' needed.
Matt S

[Ramshackles]

Originally Posted by Matt Syson

Hi
If it is being 'sourced' from converters or other inputs that are balanced, then the output will also be balanced if you have built it 'correctly'.
You won't 'NEED' transformers and in any case, using transformers with a higher ratio would be beneficial anyway as it would reduce the amount of 'makeup gain' needed.
Matt S

Hi. Yes, or course the input for the summing module will come from converters - there may be a hardware EQ or comp on the way, but whatever, it will all come from nominal +4dBu outputs.

I know transformers are not at all necessary to balance the output, but my thinking was to use transformers on the outputs mainly for the 'mojo' and also for the isolation - this module may become part of a larger summing setup in the future (i.e. it may become a single bus/group feeding a further summing module)