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mob-audio-io-stage

Audio I/O Stage Module Board

Audio input and output stages module board. This MOB operates at 9V or more for VCC (rail voltage of op-amps) and VCC/2 for internal VR (reference voltage for virtual ground). The input is a buffer stage, the output stage has a selectable gain (jumper JSW2) between 1:1 or 2:1.

mob-built

Schematic

mob-schematic

PCB Layout

mob-pcb

Bill of Materials

  • paperboard 5x7cm

  • 2-pin (Molex-KK) VCC-GND power connector

  • 2-pin (Molex-KK) external VS-GND power connector

  • 4 x 2-pin (Molex-KK) input/output audio connector

  • 2 x bulk capacitor (tantalum) 10uF

  • 2 x led current limiter resistor 2K2Kohm and 1Kohm

  • 2 x power activity led green 3mm

  • 3-pin voltage VS internal/external selector header

  • 3-pin output gain selector header

  • 9 x resistors: 1 x 1Mohm, 2 x 470Kohm, 1 x 100Kohm, 4 x 47Kohm, 1 x 100ohm

  • 1 x decoupling capacitor C=100nF

  • 1 x bulk capacitor 47uF

  • 5 x filter capacitor 1 x 10uF, 3 x 1uF, 1 x 4n7F

  • IC Dual OpAmp NE5532 with socket DIP4+4