Mixing console - single opamp audio mixer

The majority of audio mixer circuits published to date in Elektor (and other magazines) require a relatively large number of components. However, a simple unelaborate system could also prove effective, especially when only a few signals are to be mixed together. 47k log. 47k log. 47k log. 47k log. 680n The circuit described here utilises a single opamp as the summing amplifier. The individual input signals are connected to the 100 Idt "adder" resistors at the inverting input of the opamp, after being fed through the "mixing" potentiometers. Normally, there will be no need for any series 9 ... 15 V 10 W16 V 9 ... 15 V IC1 = TDA 1034 LF 356 TL 071 TL 061 TL 081 741 capacitors to be connected to the inputs, as the majority of todays signal sources do not produce a DC voltage level. Nevertheless, if it is considered necessary, 330n capacitors could be included. Readers may add as many inputs as they like. The overall quality depends entirely on the type of opamp used. Recommended type...