Line out to mic in

How can I do ?
Line out and mic mix and convert to mic level because record sound my phone.
Do you have to diagram ?

line out + mic ------> mic in

Line out and mic mix

Mic mix? What? You CANNOT connect two (or more) outputs* together (like connecting a mic to a line output, or connecting the line outputs from two CD players into one amplifier input. You need an [u]audio mixer[/u] with at least one mic input and one line input. Or, if you are using a computer you may be able to configure your computer to work as a mixer.

Note that audio mixers are designed to work with studio/stage mics a low-impedance, balanced (3-wire) connection. They don't work properly with computer mics (high impedance unbalanced 2-wire, often requiring 5V power).

A microphone signal is about 1/100th of a line-level signal (depending on the "loudness" of either signal). You can make a 100:1 [u]voltage divider[/u]. The sum of the resistances in the voltage divider should be in the ballpark of 10K. You may have to experiment with different resistor ratios to get it "just right" or you can replace the bottom resistor with a potentiometer, and take the output from the pot's wiper.

You'll may also need a [u]adapter cable[/u] with a TRRS (4 wire) connection for the phone and a TRS (3-wire) or RCA connections for the source. (I'm not recommending that particular adapter, that's just a picture.)

  • It's OK to connect two (or more) inputs together, so for example it's OK to connect the line output from a CD player into two amplifiers.