Microphone (3.5mm plug) to an ADC (phono interface)

A phono input applies some frequency corrections, known as RIAA correction. Basically, a phono input boosts low frequencies while dimming high tones. Apart from that correction, 'phono input' does not fully describe the type of input. It can be meant for anything from crystal to MD to moving coil.

Also important to know is the type of microphone involved. Most low-cost microphones are elektret nowadays. Which means, that they output a voltage that is OK for a crystal type input but is far to high for any other phono input. Elektret also requires either some powersupply (not available on a phono input) or a high impedance input (available if the phono input is suitable for crystal; but most aren't.)

If your microphone is of the 'dynamic' type, the voltage levels won't cause any problem if the phono input is meant for MD. (Most are.)

All by all: using a phono input to amplify a microphone is not the easiest way to go :-)

Radio Shack carries those.

Well I don't have much choice with using phonos as input as these are fixed, however I do need to be able to connect microphones to phono sockets. As you have quoted, the microphones I intend to use are just low-cost electret based microphones. I haven't quite determined what type of input the phono inserts are. I need to look into this. I do have electret microphones that come with power, so given the right plug converter, this could work.

If you have info on the different types of phono sockets, that would be helpful.

Best Regards,

Binod

Gerard Bok wrote:

That being the case, I suggest you take a look at

By the way, the type of phono-input cannot be determined by the type of socket. Most common phono input is MD (Magneto dynamic, 47 kilo-ohms, a few millivolts)