[quote author="WJS"]first off, my'g9' based pre, is very loosely based, (I started a thread in the lab on g9 mods with a link to the schematic) and there is no gain knob so zero is already out the window there... and what kind of impedence are we connecting to the input? nothing? short? there are too many variables in my humble opinion to make this usefull. I also dont really have a way to measure the noise other than hooking it up to my mixer and reading the channel meter. if you really want this i'll do it....
Bill[/quote]
Sounds like its not a G9 clone??? Which makes it ineffective for this purpose, simply because we won't get enough measurments to get a accurate average. However, since you have 6 channels built you can still try to see how consistant the noise is in your circuit.
You can try to measure the output of both shorted input and no input with output turned up half way, do you get a lot of difference in the noise figure between shorted input and no input??
Try it on all 6 channels and see what you get in terms of rms, and post the result if you can.