Got some Newcomb input trannies. Now what should I do?

[Rodgre]

I just inherited some Newcomb TR-100 input transformers. They have 125/500 Ohm primaries and nothing listed on secondary other than "Sec to grid". Would these make good mic input transformers for a preamp? Any thoughts on what sort of preamp design I should pair them with?

Roger

[winky dinglehoffer]

"sec. to grid" would suggest a high impedance on the secondary--probably between 50K & 100K. Should work well for (some) tube designs & possibly for something like an API-style mic pre (1:10 transformer, if I'm remembering right.) If you can find a schematic from an old Newcomb mixer, you might get some clues from there. Sorry I don't have more info to offer.