The A-127 is a triple resonance filter with three separate voltage controlled band pass filters, each with it's own LFO (triangle) with LED display and adjustable frequency and amplitude. Instead of the internal LFO an external CV can be used to control the filter frequency. Each filter has it’s own separate audio output, along with a mix output.
The input signal can be added to the triple filter mix signal with a separate control. All of the 3 filters share a common attenuated audio input. The audio input is very sensitive so that distortion can be used to create new sounds - if desired. The frequency control range of the bandpass filters is about 40Hz ~ 6kHz, and the LFO rate is about 0.02Hz ~ 20Hz. Each filter can be used also as a resonant 12dB low pass instead of band pass. For this a jumper per filter can be changed on the pcb. In which case the module becomes a "triple low pass filter".
A breakout module (A-127 BOM) is available to allow individual filter inputs, and all filter mode outputs.