Hi Jason, well, mine's not working yet, but I have a 1ma meter (same type as used in a gssl)... I'm pretty sure that's what was called for
PRR said.
GR metering can sense either 12AU7 cathode current or grid voltage. This is a little annoying because both points are referenced to +12V. This complicates using one meter for either output level or GR level. But you have level meters on your recorder. A milliampmeter plus a shunt resistor in R3's location is the simplest way to indicate relative GR. Adjust the shunt so the meter indicates full-scale at no-signal.
the meter out's on Kent's board have a trimpot, so you should be able to dial in your scale and if you can't you should get a higher value trimpot or throw some resistance in series.
50ma seems like it's way to big.
hook up some external meters, like on your DAW
with the threshold control all the way open watch the meters and your test signal level and figure out where compression starts.
your meter should be zeroed out right there and as you lower threshold you should see your output meters drop. your gain reduction meter should drop accordingly, otherwise, try messing with the trimpots and see what happens.
As to the scale corresponding to the needle, I think you might have to mark it out on the meter and then open up the meter and print a scale in your graphics program that corresponds to your gain reduction.
There's probably some way to take the tube curves into account and build up some kind of logarithmic meter amp that tells you what you want to know PRECISELY, but this is the quick and dirty way to do it and your meters will probably move a bit when you hit the compressor soft and a lot when you hit it hard.
Kelly
