passive summing box with selectable o/p irons?

[tripledot]

just a thought...

For now I do all my summing ITB but after reading through the analogue summing meta I've decided to give NY Dave's summing box a bash. So, 16 channels (8 stereo pairs from my MOTU 24io) to a single stereo pair, all fully balanced, minimum signal path (no mutes or pan switches) bla blah blah... it all makes sense.

Gain make-up. Now this is where I get confused. Sorry for asking such a stupid question, but I know I'm out of my depth ...I want the resulting summed signal to go back into my MOTU's line inputs, so obviously I need a preamp of some kind...

Given that this box is going to be permanently patched into my MOTU, I only really want the preamp to gain my precious signals back to line level. Is it possible to use simple trafos to give me that gain boost, instead of building a mic pre with all the trimmings? If so, I wonder if, with appropriate shielding, I could use a switch to select different trafos for different tone?

I'm anxious not to repost tired old questions but I'm struggling to find basic trafo information. What else do I need for a beautiful-sounding preamp!?!? any schematics would be greatly appreciated!

thanks, chris.

 

[skipwave]

Kubi's right. The insertion loss is too great. The design creates a 40db loss. You need an active stage for that amount of makeup gain.

The gain from a transformer is never free. Impedance conversion is their main purpose, the gain is just along for the ride, and in most designs with a stepup at the input there was a nearly-as-large stepdown at the output.