audio processor circuit schematic

Audio Processor Circuit

This audio processor circuit features the SSM2045 IC which was developed specially for electronic music applications and the 741 opamp IC. The circuit is configured as a low pass filter with a DC voltage control for gain. The input signal is set to a working level of 150mVpp through the resistor R1.

How does the audio processor works

The filter has 2 buffered outputs: the 2-pole output at pin 1 and 4-pole output at pin 8. Internally, the outputs are connected to 2 voltage-controlled-amplifiers (VCA).
The R15 and R16 are connected to these outputs to achieve optimum offset and control voltage suppression.

P4 is the volume control. The current that flows to the pins 15 and 16 should not go beyond the maximum of 250 µA. The balance of the two VCAs and the entire filter is being controlled be a voltage range of -250 mV to + 250 mV at pin 14.
This voltage can be set by P2.

The input can be driven with source impedances up to a maximum of 200 Ω. With an input level of 0dBm, the VCA weakens by 6 dB. The bias current needed at pin 17 is between 120 µA and 185 µA. The cutoff frequency can be shifted between 20 Hz and 20 kHz with a variable voltage at pin 5. This can be varied through P1. The capacitor values were selected to give the filter its Butterworth characteristics.

The output current of the SSM2045 IC is converted to a voltage output by the 741 opamp. Any sybsequent circuit must be DC decoupled from IC2.
The noise-voltage ration is about 80 dB.

Audio processor circuit schematic

audio processor circuit schematic

Sent by Claudio, IT


Join the conversation!

Error! Please fill all fields.
  • Mike

    Do the SSM2045 circuit have 4 pins labeled 15?
    -“The current that flows to the pins 15 and 16 should not go beyond the maximum of 250 µA”
    Hello? You short these two pins according to your schematic.
    I hope no one have tried this, because you will fry the chip!


      It pays to check more than one manufacturers’datasheets as I have discovered some that were the same number but completely different ic

  • johnson

    I want use this circuit


    Good&qulity circuit that iam use in my hi-fi home theatre system.Sound performance is nice with good dynamic range .also i use it in comercial PA system with little adoption circuit for punched bass & grisp treble.Thanks.

  • Kotag

    you have a audio processor circuit with ic LF347 sir ? ineed this/./.

  • kwabla

    good circuit.pls help me know the importance of an audio processor.can i connect it to my amp.if so what can be the outcome

    • Alexander

      этот корректор звука применим к любым усилителям большой мощности с двух полярным исмточником питания. (the sound equalizer is applicable to any high power amplifier with two polar ismtochnikom supply.)

Looking for the latest from TI?