– 13 –

CXA2021S

<Description of Operations>

• AGC circuit

The AGC circuit is incorporated in the input block. When AGC is turned ON, gain is 0dB for small signal

input, boosted for medium signal input and reduced for large signal input. The AGC circuit can absorb

volume differences between input sources.

• Surround circuit

L-R signals passing through the phase shifter are added to L channel and R channel each in the opposite

phase. The transfer function of the phase shifter is obtained by the following equation:

Vin

where R is internal resistance

≈ 18kΩ and C is external capacitance.

• TONE circuit

BASS and TREBLE tone control. BASS control characteristic can be determined by external capacitance

can be performed in 32 steps.

• BALANCE and VOLUME circuits

Controls BALANCE and VOLUME in 64 steps each.

• DAC

DAC circuit for controlling BASS, TREBLE, VOLUME and BALANCE. Internal impedance is approximately

20k

Ω. Connect external capacitance for LPF.

1 – SCR

1 + SCR