Yamaha VL-7 Owner's Manual page 63

Feature Reference
High Control
Sets the reverb time of the high frequencies in relation to the overall reverb time.
Higher values produce longer high-frequency reverb times, gradually approaching the
overall reverb time.
Diffusion
Adjusts the left-right "spread" of the reverb sound. The higher the value the greater
the spread.
Initial Delay
Sets the delay time before the reverb sound begins.
Initial
Delay
Feel
Selects one of four variations in density or overall sound available for each of the
VL7's reverb types.
Bass
Emphasizes the bass frequencies. The higher the value the greater the bass empha-
sis.
Treble
Emphasizes the treble frequencies. The higher the value the greater the treble
emphasis.
Edit Mode
Reverb
Time