An implementation of a Class A amp. Capacitors act as isolators for the DC voltage, only letting the AC voltage through.
An audio mixer adds separate frequencies together to produce a single frequency. With this circuit, you can have as many inputs as you want.
To increase the gain, we bypass the emitter resister with a capacitor. This allows the AC voltage to go straight to ground without providing negative feedback.
The inputs have a different impedance value (The 50 and 600 resistors) To accommodate for this, we swamp the input with a large resistance on both inputs, so the difference in impedance is negligible.
I included some switches to exclude a source if you wish. Go ahead and play with the frequencies to see the output.
