Quote:
Originally Posted by lontas  Hello,
I have a device with on-board transformerless mic preamps. They have an input impedance of 1.6k, which is too low for my tastes. I would like to raise it to 2.5k or even higher. But it is impossible to get access to the schematics, so I will be manually tracing the circuit.
1) Am I correct in thinking that the input impedance is set by a 1.6k resistor connected somewhere between the Pin 2 and Pin 3 signals?
2) If that is correct, then is raising the impedance really just as simple as raising the value of that resistor? Or is it more involved than that?
Thanks! |
Why is that too low for your "taste"? That statement doesn't make sense to me. What is the source imepdance? A lower load impedance will mean more signal loss while a higher load impedance will mean more noise. As long as your load impedance is about 10x your source impedance you should have nearly max signal transfer.
Load loss = 20Log(Rload/Rload + Rsource)
If you are absolutely hell bent you could build a buffer.