The Grand Orbiter Phase Machine is a four-stage OTA phaser, with options for vibrato or phasing (a bit like a Univibe).

Not exactly a small board, but not too much to take on either.  MLC caps might be a good idea for some of the 1uf caps to save space. 

Currently unverified.  I have reviewed the schematic a couple of times, and two errors have been found and corrected, but still…  it’s a huge board.  What could go wrong, right?

EARTHQUAKER DEVICES GRAND ORBITER PHASE MACHINE – VERO LAYOUT