Marantz SC-6 - Page 5

MARANTZ MODEL Sc-6 STEREO CONSOLE AMPLIFIER
tone loudness (“ORT meniter input
Lm tape selector
FEATURES
@ MC head amplifier @ TONE switch
The first stage uses 4 super-low noise NPN transistors and
4 super-low noise PNP transistors connected in parallel
to form a push-pull circuit. The second stage is also a
push-pull circuit. The output stage is a high gain SEPP
amplifier. Totally, 13 transistors are used for a channel.
The feedback circuit has very low impedance, thus im-
Proving the S/N. With this design, this MC head amplifier
provides a high voltage gain (20 dB or 10 times) at a rated
input of 220 uV.
PHONO amplifier
The PHONO amplifier is a unique Marantz full-stage push-
pull circuit using 11 transistors that ensures low TIM
distortion and a high S/N.
The first stage uses super-low noise, high Gm FETs in
push-pull connection (N and P channels) and a cascode
Current mirror circuit to prevent the deterioration of the
characteristics due to changes in input impedance. The
PHONO signal is fed through the emitter follower buffer
amplifier to the push-pull voltage amplifier in the second
stage.
The output stage is an SEPP circuit which has sufficient
driving ability. The equalizer circuit has a very low im-
Pedance so that the S/N is a high 90 dB at the rated input.
This circuit uses high quality metallic film resistors
(41%) and polypropylene capacitors (2%) to reduce the
deviation from the RIAA characteristic to less 0.2 dB
at 20 Hz ~ 20 kHz.
Optimum cartridge load can be selected between 27 kQ,
47 kQ and 100 kQ by using the PHONO switch on the
front panel. The input stage includes a muting relay to
eliminate the shock noise which is normally generated
when the power is turned on and off.
The output stage is also provided with an EQ subsonic
filter to eliminate wow and flutter generated by the
turntable.
a
By using this switch, the output of the PHONO amplifier,
passing through the coupling capacitor, is directly fed to
the main amplifier without affecting the gain and input
sensitivity, thus the line amplifier operates inthe TONE
IN/OUT mode.
TONE-OU HE. ADPHONE
OUT
e@ LINE amplifier
The Class line amplifier is a unique Marantz full-stage
push-pull circuit using 15 transistors that ensurts flow TIM
distortion and a high S/N. This fullstage DC amplifier
employs a unique Marantz circuit design to rninimize
TIM distortion and a DC servo circuit to elinimate DC
drift.
The input stage uses a matched pair of dual FETs as a
source follower amplifier to prevent the deteroration of
the characteristics due to changes in input mpoedance.
The low impedance signal is amplifier by the dual tran
sistor differential amplifier with an active load balancing
circuit. The differential output is fed through he emitter
follower buffer amplifier to the push-pull anpalifier in
the next stage.
The power amplifier stage uses newly developed super
high fy (70 ~ 90 MHz) power transistors coinected in
parallel to form a 2 stage Darlington circuit The new
circuitry with pure Class A operation compleel y elimi-
nates switching and TIM distortion. Headphoms are also
driven in Class A.