Doug Ford, former head designer at Rode Microphones explains 48V phantom powering of microphones and how it works.
There is a ton of stuff here:
Electrostatic and electromagnetic noise, differential amplifiers, common mode noise, transformer magnetisation current, JFET differential driver circuits, balanced impedances, phase splitters, miller capacitance and how it matters, and he explains how the Schoeps amplifier topology works.
$140 for a 2CH 100MHz 1GS/s tablet oscilloscope? Review of the $140 FNIRSI-1013D 2CH 100MHz ...