Main synth upper octave cut-off

The Pinnacle's MA-1 sampling engine uses different rates to play back 
different notes.  It normally plays at 48 kHZ, and can play up to 96 kHZ. 
As it passes 96 kHZ, it will stop playing.  Effectively at 48 kHZ, if you 
go an octave up, you have doubled the frequency and also reached the end of 
the range. Therefore, you will not get any sound.