This is something i've noticed to - I ordered 4 sets of standard cos's (from a well know UK distributor) two in ta5 and two in 3-pin lemo - going into lectro transmitters. I'm normally an 4060/61 guy, but for continuity with an existing show, I added the above.
I've noticed that across the board, I'm running them around 30-36 to get them to modulate properly for normal dialogue - much higher than what I am used to (18-24)
is the general consensus that its the resistor thats the culprit?