I have that value from my 861v3 and from 565.
Play a very low signal or music and turn up the volume to 87, listen if the signal its not distorted untill you go o higher numbers.
But take attentation only use low level signals otherwise you dont need that test anymore...

Robert


800v3/218/271/8k.2/5k5s smile /5kC/DSP3200/Reviver/
TT-ELP/Graham Slee Revelation/Trinnov Altitude 32/OPPO 205
__Ayon/HB/Shunyata/Miltzow -- power cables,
__Ayon/Jungson/Miltzow --analog, Miltzow-- digital,
__Vortex/WMA ,