Marsona 1200A Noise Generator

via this auction

"Vintage Marsona 1200A.
This unit was made as a sleep-inducer. It is actually an analog white noise generator.
Selector Knob - Off/4 Noise Modes: Surf I, Surf II, Rain, Waterfall.
Surf Rate Knob - Slow>Fast
Surf Range Knob - Low>High
Tone Knob - Bass>Treble
Volume Knob - Min>Max
Surf I and Surf II are modulated white/pink noise.
Pulsating from a trebley white noise to a moremuted pink noise.
Rain is more like plain White Noise.
Waterfall is more like plain Pink Noise.
I'm not sure if it induces sleep, but it makes a good and highly usable noise signal.
It's also circuit-bendable or makes a good enclosure for synth projects."