Microphone Preamplifier Circuit

Mixer Circuit

Clipping Monitor

Tone Volume Balance

Power Amplifiers

Power Supply
The appearance account of this arrangement are:
* Six absolute microphone amplifiers with up to 60dB accretion (theoretical, not tested). Each approach has an absolute fader and an attenuator to acquiesce affiliation of agreeable instruments which accept line-level outputs (such as synthesizers).
* Mixer to amalgamate all the six [...]

Mixer circuit above 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 [...]

Small portable device – 9V battery operationThree high/low-sensitivity switchable inputs
Although the modular Portable Mixer design available on these web pages has become a hit for many amateurs, some correspondents required a much simpler device, mainly for mixing mono signals. This design should fulfil their needs, featuring three inputs with switchable high/low sensitivity and unusual level-control [...]