(All of these controls are in groups of four, one for each operator. Operator 1
is on the left followed by operators 2, 3, and 4.)
The label for this section is a button which brings up a menu, and this is
documented in the section on Menu Buttons.
The four LCD controls at the top of the output section are the operator output
levels. For carrier operators, this is the volume. For modulator operators,
this is the amount of modulation that is applied by the operator.
Operator Enable Buttons
Directly below the output level controls are four numbered buttons. These are
the operator toggle buttons, and they are used to temporarily disable operators
so you can listen to certain operators individually as you edit the sound.
If the button is pushed down then the operator is enabled. The settings for
these buttons are not stored with the sound. That is, all operators are always
enabled when you change patches on the TX81Z, even if you stored it while
operators were disabled. If you want to permanently disable an operator then
you have to set its output level to zero.
The key velocity sliders determine how much each operator will be affected by
the speed in which the keys are pressed (provided you are using a
velocity-sensitive keyboard, of course). Turning these up actually
decreases the overall output level of the operators, so it would be more
accurate to say that these determine how much a lack of velocity affects
the sound. I often find myself turning up the output levels to compensate for
the decrease in overall output level.
Scaling represents the change in output level across the keyboard. Rate
scaling compresses the EG time as you go up the keyboard, so the envelope will
sound shorter/faster. Level scaling will decrease the output level as you go
up the keyboard, so the notes will sound softer.
And, just in case you're wondering, yeah rate scaling does belong with the EG
parameters. I just like it better over there on the left :-)