197

Audio ICs

BA3308 / BA3308F / BA3308FV

(2)

Playback (See Fig. 7)

During playback, the ch1 and ch2 amplifiers are used as

NAB equalizer amplifiers, and time constant circuits are

connected between pins 1 and 3, and 7 and 9 in the nega-

tive-feedback section to give the NAB characteristics.

The voltage gain is given by:

In the same way as for recording, the NAB time constant

circuit is adjusted to give the required gain (to prevent

generation of a “pop” noise when power is applied). The

5V, the maximum output voltage will not exceed 1.2V

(typ.). The ALC circuit is not required for playback, so pin

5 is grounded. The S / N ratio during playback is better if

input pins (2 and 8) for recording are switched out.