YouTube entry says :
Casually testing out the rare analog beauty, Rocktron Prochorus. It is BBD-based, stereo analog chorus. Derived from the MN3011 chip, this unit has as much tonal flexibility as digital choruses, but in analog format! Each of the 6 taps have a set delay time, with longer delay time producing a 'thicker' chorus sound. Each tap can be panned to left, right or both for mono signal. Combine this with controls for rate, depth, and width, and the ability to assign overall mix for right and left channel, and you have the ultimate analog chorus! There is also a regeneration control that can be assigned at the first or last tap for more extreme flanger type sounds.
Listen to the Demo