"
I've got the output from the present inverting chip going to a 10k resistor and a 10mfd capacitor. Do I really need these? "
Won't hurt but 10 k in series? That will restrict HF on a long cable. Classic output config' is a series R of 74 to 120 Ohms* a series capacitor, 10mfd is fine into typical 10kZ inputs and a 'tie down' resistor of about 100k to keep DC from bleeding onto the OP and causing a click on connection.
Connecting the mic directly into the summing point of a shunt feedback amp means it 'sees' approx. zero Ohms and thus the whole thing resolves to 'current' drive and the response will be all over the shop! Mics are designed to drive a virtual open circuit or at least 5 X posted OP Z.
I think I shall have to post a couple of circuit ideas? BWT I think you are in UK? If so PM me if you like.
*You should always have a such an impedance (can be a small choke) on a chip's output into the 'world' because a 'cappy' cable can cause instability. Chips INSIDE gear, not driving a capacitance can simply be DC or AC coupled.
Dave.
I've got the output from the present inverting chip going to a 10k resistor and a 10mfd capacitor. Do I really need these? "
Won't hurt but 10 k in series? That will restrict HF on a long cable. Classic output config' is a series R of 74 to 120 Ohms* a series capacitor, 10mfd is fine into typical 10kZ inputs and a 'tie down' resistor of about 100k to keep DC from bleeding onto the OP and causing a click on connection.
Connecting the mic directly into the summing point of a shunt feedback amp means it 'sees' approx. zero Ohms and thus the whole thing resolves to 'current' drive and the response will be all over the shop! Mics are designed to drive a virtual open circuit or at least 5 X posted OP Z.
I think I shall have to post a couple of circuit ideas? BWT I think you are in UK? If so PM me if you like.
*You should always have a such an impedance (can be a small choke) on a chip's output into the 'world' because a 'cappy' cable can cause instability. Chips INSIDE gear, not driving a capacitance can simply be DC or AC coupled.
Dave.