Casio CZ/ VZ/ FZ - Pro Series

As far as I can tell, HZ waveforms, if normalized, look the same when 
decayed. The volume control seems to be independent of the waveform generation 
part, as you suggested.

> What I mean is that you should look at the waveform as it decays to 
see if 
> it actually changes.  I doubt the volume control part plays into the 
4-bit 
> waveforms, there would be a lot of quantization noise and there would 
be 
> audible stepping in the volume envelope.  I would imagine that the 
amplitude 
> control comes after the waveform generation part.