Scott Dorsey wrote in message
...

Yeah, but if you're designing the thing yourself you can do it so as not
to
need 100uF. Make the resistance on the right-hand side of the cap 10k and
you can get away with 10uF. That's doable in polypropylene.

That's where the rub is. You want a low input impedance on your preamp,
so that it properly loads dynamic microphones. BUT, you want a high input
impedance, so your phantom blocking caps aren't enormous.

With a 600 ohm input Z, 10 uF gives you a -3dB point at 20 Hz or so, which
is kind of high, I think. But not insane.

So put your 600 ohm or whatever oad resistor on the left side of the
capacitors, between the two input pins. They have the same DC voltage on
them, if your phantom resistors are matched properly, so no current will
flow. Total AC load will be the resistor across the pins in parallel with
the 10k on the right side of the caps.

Peace,
Paul