Ian MacGregor
Well-known member
I want to build a 8-stereo channel (maybe more, but let's start with 8) summing box using Neve 1272's (real or DIY'ed) for makeup gain. I am kinda familiar with how passive summing box's work (like the Folcrom); is this the same concept? Using the 1272's kinda how the Folcrom uses mic-pres? Except that 1272s were designed for the lower gain range?
Ok, so here's what I'm thinking: Have each pin 2 and pin 3 on the input XLRs connected via a summing resistor (5k??? have no idea...) to the primary of the 1272 input xformer. All the pin 2s will go to one leg of the primary and the 3s go to the other leg. My main question is how do I know how much gain I need to have in the 1272? It would be cool to have some sort of trim control or something as well. I'm very open to doing this the way Neve would have as well, even if the noise/distortion isn't steller.
Anyway, lots of questions...
Ian
Ok, so here's what I'm thinking: Have each pin 2 and pin 3 on the input XLRs connected via a summing resistor (5k??? have no idea...) to the primary of the 1272 input xformer. All the pin 2s will go to one leg of the primary and the 3s go to the other leg. My main question is how do I know how much gain I need to have in the 1272? It would be cool to have some sort of trim control or something as well. I'm very open to doing this the way Neve would have as well, even if the noise/distortion isn't steller.
Anyway, lots of questions...
Ian