The PPG EVU was intended to be a rack mount PPG Wave 2.2 with some added functionalities.
It ended up being similar to the PPG Wave 2.3 in every way if you don't mind not having any knobs to turn - or not having a LC display to look at.
Apart from that is it a PPG Wave 2.3 in a rack.
It is considered to be much more stable than the PPG Wave 2.3. Probably so because of its lack of knobs if you ask me.
As you may or may not know the PPG Wave 2.3 is known for its way to alter the program you load into memory by adding the current knob position to that program - making the program sound different than intended; not so with the PPG EVU.
In the PPG System you could have one PPG Wave 2.3 and three PPG EVU's connected at once to a Waveterm making it a 32 voice sampler/synth/sequencer - all that anyone could ask for in the early/mid 1980's.
The PPG EVU has eight separate outputs on the front of the unit as well as a phones output and the common left/right outputs. A very cool feature of the PPG EVU that is not featured on any other PPG unit is the pan knob for the separate voices.
With these you can make some pretty cool panorama effects by setting the voices differently using the L/R outputs.