Electret bias question

[Dylan W]

Many of the schematics I've seen for electret microphones (the kind without built-in JFET) have the backplate grounded and the diaphragm connected directly to a JFET's gate (no coupling capacitor).

My question is, how does this not upset the bias of the JFET?

If the electret has an inbuilt polarizing voltage of about 60V, as I've seen some on here suggest, and the backplate is grounded, wouldn't the ~60V be superimposed on the gate of the JFET?

 

[RuudNL]

Short answer: no.
An electret capsule behaves like a capacitor.
(Try to measure the DC voltage at the output of an electret capsule: it isn't there...)