> From the gate circuits audio is fed through internal series
> resistors to the inverting inputs of the output operational
> amplifiers (pins 9 and 12), which can also be used as
> signal inputs for cassette playback or other sources when
> the mute is activated. The gain of these amplifiers is
> defined by external feedback resistors Rout
> (pins 9, 10, 11 and 12).


The soft mute facility (pin 8) provides silent tuning for RDS
processing. The mute time constant may be adjusted from
pin 8. In mute position and the VCO switched off (pin 7),
the output amplifiers can be used for cassette playback,
AM stereo purpose or other signal sources.