The SYSTEM-500 521 is in excellent condition and all controls have an excellent feel - see pictures.

All input/outputs are in good shape and make solid connections.

Comes with ribbon cable.

Used in a smoke-free environment with no pets.

I will ship safely and insured via Reverb with the default signature required; thanks for looking.

Please feel free to ask any questions.

### From the manufacturer

Dual VCF

The 521 Dual VCF (voltage controlled filter) module features two separate low pass filters for modifying the timbre of audio sources. Each filter has its own dedicated controls for frequency cutoff, resonance, and a fixed high pass filter with two switchable cutoff points. Audio and CV input mixers on each channel allow the blending of multiple audio signals and modulation sources.

Controllers:
SIGNAL IN 1 slider
SIGNAL IN 2 slider
SIGNAL IN 3 slider
MODULATION IN 2 slider
MODULATION IN 3 slider
HPF switch
FREQUENCY knob
RESONANCE knob

Connectors:
SIGNAL IN 1 jack: Miniature phone type
SIGNAL IN 2 jack: Miniature phone type
SIGNAL IN 3 jack: Miniature phone type
OUT jack: Miniature phone type
KEY IN jack: Miniature phone type
MODULATION IN 2 jack: Miniature phone type
MODULATION IN 3 jack: Miniature phone type