Sony STR-VX4 - Page 32

SONY STR-VX Series Circuit operation
STR-VX4, -VX5, -VX6 Tone a constant-current load for Q605. The
A lifi bass and the treble controls are con- |
mpiirer nected in the negative feedback loop. (
. ; The STR-VX4, -VX5 and -VX6 also
Four discrete transistors are employed have subsonic filter circuitry. The
in the tone amplifier (Figure 7). Q603 operation of the circuit is identical to
and Q604 are connected in a differen- that of the STR-VX3. The STR-VX6,
tial configuration to eliminate the com- which is the top model of the STR-VX
mon-mode noise coming from B+/B- line. series, features pre-out/main-in ter-
Q605 further amplifies the voltage sig- minals for expanded utility.
nal coming from Q603. Q606 acts as
LOUDNESS SUBSONIC
$602-1 $604-1
=
A
Q605
1) 2SA1026
Q603 Q604
2sc240l 2802401
RV6OI
250K
BALANCE
2scisis
R637
150
Fig. 7. STR-VX6 Tone Amplifier (Left Channel).