CXA2561Q
3. Playback equalizer amplifier
PB IN
FWD
AMP1
300k
RVS
Ri
PBOUT
PBTC
PBFB
R1
OUTREF
to TAPEIN
PBREF
C1
0.01µ
Fig. 3. Playback equalizer amplifier block diagram
The CXA2561Q configures the playback equalizer amplifier by connecting the external capacitor C1 and
resister R1 shown in Fig. 3.
Two systems (FORWARD and REVERSE) of playback head input are provided for each channel.
The FORWARD input pin is selected when DRSW (Pin 19) is Low; REVERSE is selected when DRSW is
High.
The playback equalizer amplifier frequency response can be set in two levels (70µs/ 120µs).
When TAPESW (Pin 18) is Low, Ri is 7kΩ; when TAPESW is High, Ri is 12kΩ.
The gain can be adjusted by connecting VR between PBOUT (Pins 2 and 29) and OUTREF (Pins 3 and 28); or
by using VR for the external R1.
T1
Gain [dB]
G1
R1 + 300k
R1
G1 = 20 log
–6dB/oct
R1 + Ri//300k
R1
G2 = G3 = 20 log
T1 = C1 · (300k + Ri)
C1 · (R1 · 300k + 300k · Ri + Ri · R1)
T2
G2
G3
T2, T3 =
T3
R1 + R2
f1
f2
f3
Frequency [Hz]
Fig. 4. Playback equalizer amplifier
frequency response
– 13 –
SONY [ SONY CORPORATION ]
