A9 Ratchet

  • PCB - top view

    PCB - top view

  • Loop gain analysis

    Loop gain analysis

  • A9 Ratchet

    A9 Ratchet

  • THD 1kHz

    THD 1kHz

  • IMD 3kHz, 4kHz, 5kHz

    IMD 3kHz, 4kHz, 5kHz

  • THD plots

    THD plots

  • Square wave

    Square wave

  • Triangle wave

    Triangle wave

  • Sine wave

    Sine wave

  • Clipping


  • Slewrate ~108V/us

    Slewrate ~108V/us

  • Stability test

    Stability test


This simple IPS board was inspired by mr Mile Slavkovic's amplifier called A9.

I have changed the VAS stage, gain, power supply, OP-amplifier and the compensation.

Overall performance is very good. The key feature in this design is the NFB network.

The feedback loop is splitted in between OP-amplifier and the inverting input of the front stage.

The inverting input of the OP-amplifier is AC-coupled so we can say it works as a ''DC-servo'' circuit.

Script logo