Dave Smith Instruments SYNTHESIZERS

>On the Poly Evolver keyboard, if I go down to a very basic patch, like on
>Anu Kirk's guide, say a sawtooth wave with just the two analog oscillators
>on, both levels at 50, and then hit the same note over and over again so it
>cycles through the 4 voices, I notice that the sound changes as different
>voices play the same note.  Kind of like what would happen with some
>oscillator slop, or a bit of a filter.  For example, I can hear a faint
>octave harmonic noticeable in voice 2 and 4.  The sound does not change if
>I hold the key down, but changes again when I hit the same key again, and
>when I get back to the voice that gave the octave harmonic, it sounds just
>like it sounded when it cycled there before.

I just have the regular Mono so I can't test this, but I would imagine what 
you're hearing is the phase offsets in the oscillators.  When you have both 
analog oscillators in tune, with osc slop turned off, no modulation, etc. it 
means the frequency of the oscillators should be the same, but doesn't 
indicate anything about the phase.  Combining two oscillators with different 
phase offsets will change the sound because the individual harmonics will 
reinforce/cancel differently (comb filtering).  The oscillators don't reset 
to the same phase when a new note is played (as far as I know), and you 
wouldn't want them to- it sounds lousy with detuning (my Casio VZ-10M does 
this and it really irritates me).  Since the oscillators aren't detuned, the 
relative phase difference stays the same and makes each voice sound 
different.  Try detuning one oscillator, then tuning it back- this should 
change the phase of the detuned oscillator and make it sound different.  To 
eliminate the effect, try turning osc sync on and then back off.  This will 
probably cover your voice 3 panning issue as well.

Like I said, I don't have the Poly Evolver so I'm really just speculating.  
Should be a pretty good guess though.