The Quad LFO gives you four independent high quality temperature stable modulation sources. While audio rate analog oscillators famously sound more alive, the living quality of analog modulators is often overlooked. The Quad LFO has a totally analog sine core, for living, low distortion, accurate, and consistent sine wave outputs. However, if you need a square wave for a clock, to drive a logic input, or for another purpose, you can set one or more LFOs to a square with a jumper on the back.
The Quad LFO provides linear voltage control over frequency, matching our perception of sub-audio rate frequencies. Each oscillator ranges from nearly stopped to around 23 Hz. It is designed for knob twiddling, with accurate potentiometers, aluminum knobs, and 1Hz easily reachable in the center.
Quad LFO: $239
LFO Phase Expander: $99
More info here: New Systems Instruments | Quad LFO