Solid great sounding ladder filter. Very easy to overdrive. Negatives: the range switch has no real purpose, the control inputs have no attenuator, no voltage controlled resonance, no signal input attenuator. But hey its cheap and sounds really good, the sound changes radically if you change the signal input level, and always very musical. +/- 5V input is classic thick driven moog sound, lower is really clean, higher means serous squashing.