I removed the R20, R21, C20, C21, and L1 and L2 from my 9000. My first impressions are that it's a bit more mid-rangey than before (after the mods mentioned earlier), but it may be my listening environment. I'll make some recordings later, through the same signal chain as my other tests, and see how it compares.
Instead of bridging the gaps with wires, I moved the output wires to the solder pads that meet with the wires coming from the tranny to reduce extra wire in the circuit.
The mic has the classic tube-mic response, which shows me how poorly insulated for sound my studio room is. Sounds from other rooms and outside (computer, fridge, TVs, planes, cars, etc.) are painfully obvious, and I live in a relatively quiet neighborhood...
Sibilance is not too bad, and that clean tube hi end is very nice, especially now with more stuff removed from the circuit. The noise level of the mic seems to be reduced a bit, too, which might be why I am noticing this even more than previously.
As a side note, I took Rodabod's advice (very good, I thought), and replaced the 9 pf cap back into the circuit. To make a long story short, it was no good, and may have been part of the problem with the mic all along. After warming up, the mic began to hiss and spit at quite a loud volume level. Since I did this at the same time as the removal of the aforementioned parts, it took me a while to trace the problem.
Chalk it up as a lesson about the delicacy of small value caps in tube circuits. I thought my solder touch was good, but maybe I burned it a bit.
The mic made these same noises to a lesser degree when I first got it (used and abused), but I thought I had repaired it when I found a stressed wire coming from the tube socket.
It's a whole new mic now, and much better than before. It's given me a good education.
Thanks all...
Jim