Yamaha SY85 Owner's Manual page 241

Levl (Send level)
168
SONG EDIT MODE /
1)
CS6 (EFFECT
1./. (a and b off)
1a/. (a on, b off)
1a/b (a and b on)
1./b (a off, b on)
If a "single" type effect is selected then only stage "a" can be selected. If a
"cascade" type effect is selected, then only stage "b" can be selected. If a
"dual" type effect is selected, then both stages "a" and "b" can be selected. An
effect stage that cannot be selected is represented by "-" on the display.
Range: 0 ... 127
Controls: [CS8], [-1] [+1], Dial
This parameter adjusts the amount of direct voice signal that is sent to the
effect processors, determining the strength of the final effect sound. A setting
of "0" results in no effect, leaving only the "dry" sound. The maximum setting
of "127" produces the maximum amount of effect.
SONG EFFECT
CS7 (EFFECT 2)
2./. (a and b off)
2a/. (a on, b off)
2a/b (a and b on)
2./b (a off, b on)