Classe Audio CP-500 Owner's Manual page 13

In addition to receiving IR commands, the CP-500 can also transmit IR
commands so they may be learned by third-party learning remote controls.
The CP-500 includes a comprehensive list of discrete IR commands to
facilitate the creation of reliable macros. Specifically, there are discrete
codes for all commands that normally operate as toggle functions (e.g.
separate operate and standby commands in addition to the normal
command that toggles between the two states).
6 Volume Knob
The large knob on the right side of the front panel of the CP-500 is used
to control the volume of the system.
The volume is raised or lowered in precise 0.5dB increments throughout
the range of the control most likely to be used while listening to music.
At extremely low volumes, the step size is increased somewhat to make it
easier to move quickly between extremely low and normal listening levels.
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