6 (or 8) channel mic pre using active input tranny and tube output; possible?

[jrudi]

Newbie post:

Many years ago, I purchased two used Northern Electric mic pre chassis (no pwr supply nor 70v output ckt) with the intent of "someday"... Well, someday is here, and I realize I can use some sage advice (or thyme advice, if you prefer).

The units no longer have input xfmrs, so I was considering using Altec 1588B transformer/preamp modules in their place, which I have some experience with. Even though I had my original training with vacuum tubes, I have never done anything of significance with them.

It has occurred to me, that the 1588B's could produce too much gain - rated @ 35dBm gain, standard; up to 50 dB with the Ned Clayton mods - for the input to a 12AX7, as I understand that the AX7's are usually used in low-level circuits.

I suppose I could modify the gain of the 1588's down, but what is a reasonable input level for a 12AX7? And at what point does this become a fool's errand; or is it already one?

Any and all thoughts appreciated.

Jeff

[PRR]

Welcome.

> at what point does this become a fool's errand

When we try to give advice on an un-specified and probably obscure preamp without info or plans. *Which* Northern preamp? "70V output"?? "35dBm" is a level not a gain; typo?