EKO 2 Bass Pedal Synth

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via this auction

"The main functions are for Tuning, Sustain & Percussion. An On\Off switch and power light. 16, 8 & 4 octave switches, and indicator lights. Sustain on/off. When on, the knob above operates, when off, it decays quickly and a volume control

It then just plugs into an amp or PA (no midi). On its own it sounds big, deep and smooth, and can do 'Hammond -style' bass very well."