Thanks for the quick response.
A 10K resistor from vcc and it works very well.
I plan to use this preamp in conjunction with a CMOY amp for my home built audio system for my motorcycle.
The CMOY amp does a great job of amplifying my Garmin and MP3 to my helmet speakers. I now want to be able to communicate with my wife (passenger) when we take a few longer trips this year as I am retiring.
Can this preamp be used for both mics or will I need to build another circuit? Also, Is it possible to power both the preamp and CMOY amp from the bikes 12v system or will I be getting too much noise and feedback?
I know that I could have bought a bike communication system, but I love to learn new things and it is so much better when you do it yourself.
Thanks again
Harry