Vocal Zeppler

If you love to sing and you feel your voice is not good to hear, you are obliged to make this simple circuit. Because this tool will make your sound quality will be better.
Consider the following sequence:





Description:
The specialty of this series the possibility to use background music from your stereo system.
When the position of SIA in normal circumstances, the second input terminal (J1 and J2 to the left to right) will be mixed simultaneously (mono).
J3 and J4 same output. R11 potensio mic controller. SIA to move to the position Zapping it will be stereo.
And it should be noted the signal from the music, the volume should be as small as possible and SIA are in normal position. During the SIA on Zapping position then you will spend your golden voice in front of the mic. This circuit requires a 9 V DC power.