Mixers

This is a classic signal mixer that is used for audio purpose. VR1 & VR2 are inputs audio volume controlers and VR3 is used to control the balance between Input1 and Input2. connect a dynamic microphone to Input1 and a music without vocal to Input2, then adjust the VR1, VR2 and VR3 for obtaining a good mixed audio signal from the circuit Output. VR4 is an optional volume control for output audio signal.

The PC soundcards are typically designed to accept the audio signal only from one CD-ROM drive. Even if the soundcards have many types of CD-ROM audio input connectors those are just wired together and are designed to be used so that there is only one sound input in use at one time.

This is an image Schematic. No Description available.

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.

This project is a 3 or more lines mixer. For more than 3 inputs you can repeat the input parts (P=10K R=22K). It powered with 9Vdc.

Description is not in English language.

This is an image Schematic. No Description available.

The target of this project was the design of a small portable mixer supplied by a 9V PP3 battery, keeping high quality performance. The mixer is formed assembling three main modules that can be varied in number and/or disposition to suit everyone needs.

With this circuit you can mix four separate audio inputs. Each input will accept high or low impedance microphones, phonograph, tape or aux signals. You can adjust the gain of each input by adjusting each respective pot. With the Stereo/Mono switch you can combine just inputs 1,2 and 3,4 or in the Mono position combine all four inputs.

The mixer circuit below has 3 line inputs and 3 mic inputs. The mic inputs are suitable for low impedance 200-1000R dynamic microphones. An ECM or condenser mic can also be used, but must have bias applied via a series resistor. As with any mixer circuit, a slight loss is always introduced. The final summing amplifier has a gain of 2 or 6dB to overcome this. The Input line level should be around 200mV RMS. The mic inputs are amplified about 100 times or by 40dB, the total gain with the mixer is 46dB. The mic input is designed for microphones with outputs of about 2mV RMS at 1 meter. Most microphones meet this standard.