via
this auction
"This is one of the most famous effects units that were produced in the 70´s. The Compact Phasing "A" was made in Berlin by Gerhardt Schulte, and this thing was heavily used by Krautrock bands and electronic musicians not only in Germany: Kraftwerk, Tangerine Dream, Oskar Sala, Jon Lord, Rubycon, J.M. Jarre, Pink Floyd...
It´s possible to use it in a very subtle way, but it´s more interesting when you play with knobs to get more deep, dramatic and esoteric tones.
This is the rare white version which i bought some years ago from the first owner. The thing is in very good condition and comes with the original footswitch. You need the switch to get the Leslie-like brake sounds as you can start and stop the LFO with it.
It uses 220V power, but there´s a jumper inside that you can switch to 110V."