FM Front End With Dual-Gate FET’s, Buffer Amp
FM tuner’s sensitivity, overload resistance (ability to
receive very strong signals without distortion), image
rejection and spurious rejection are determined chiefly by
the front end. In the SX-1010, latest components and circuit
technology have been employed to bring all these values
close to their theoretical limits: three dual-gate MOS
FET’s, RF amplification, and the inclusion of a buffer
amplifier between local oscillator and mixer stage. In all
performance characteristics, the SX-1010’s FM tuner compares
favorably with the world’s most advanced specialized tuners.
It hardly needs to be mentioned that the FM dial is of
course divided into equal “linear” intervals and that dual
tuning meters — signal strength meter and zero-center meter
— are provided for easy, precise tuning.
Ceramic Filters And IC’s In IF Stages For Sharp Selectivity
A total of four ceramic filters in the IF (intermediate
frequency) stages give sharp selectivity and never need to
be realigned. Integrated circuits functioning as limiters
provide stable operation and excellent capture ratio (the
ability to distinguish between a wanted and an unwanted
signal on the same station band).
Quadrature Detection, Phase Lock Loop (PLL) Stereo Demodulator
Detection of the frequency-modulated signal is performed by
the “quadrature” method with a balanced-bridge type
differential amp. This costly design assures linearity
throughout the frequency band and reduces distortion to the
minimum. In the MPX circuit, a phase-lock-loop (PLL) circuit
design is used to give clear, stable separation at any audio
frequency. The circuit is equipped with an 1C (replacing six
transistors) in a bridge configuration.
All IC-Equipped AM Section With Linear Dial
Only very few receivers can boast a linear station dial even
on AM — the SX-1010 is one of them. The AM circuitry uses
integrated circuits in all stages for sensitive, stable and
Balanced Positive And Negative Power Supply With Heavy-Duty
The power supply unit — backbone of any amplifier — is of
the most elaborate type such as used anywhere in home-use
audio equipment, with balanced dual polarity supply and
extra large 18,000μΡ capacitors. This results in a
tremendous reserve of power for transient peaks, but also
eliminates the irritating switching noise often encountered
in less professional designs.
PHONO Equalizer With Wide Dynamic Range And Extremely Close
The incoming phono signal from a turntable is equalized
precisely according to the international RIAA standard
playback curve — within 0.3 dB of the ideal. Moreover, the
phono inputs can accept relatively strong signal levels
without distortion (250mV rms), resulting in a wide dynamic
range. This is due to the circuit design with three
direct-coupled amplification stages including a differential
amp in the first stage.
Twin Tone Controls Permit Precise “Shaping” Of Sound
The overall frequency response curve can be controlled in a
total of seven ways. Twin controls in the bass range permit
variation at 100Hz by ±10dB in 2dB steps, and at 50Hz by
±5dB in 2.5dB steps; similarly, the high controls give ±10dB
correction in 2dB steps at 10kHz, and again ±5dB correction
at 20kFlz in 2.5dB steps. All tone controls can be removed
from the circuit (by setting the TONE switch at OFF) if
desired. High and Low filters are provided for solving
specific noise problems, while the Loudness switch boosts
the very low and high frequencies at soft listening volumes,
giving a more natural sound contour. In one word: the
SX-1010 gives you complete mastery over what you hear.
Direct-Coupled Power Amplifier Supplies High Output Power
With Minimum Distortion
An all-stage direct-coupled design with two differential amp
stages and three Darlington circuits, purely complementary
and without output capacitors (OCL), the amplifier delivers
a floor-shaking — watts of music power (or 100W per channel
rms, between 20Hz and 20kHz, at under 0.1% harmonic
distortion). The power reserve is, in a single word, abundant.
... Plus A Wealth Of Auxiliary Features And Circuits
Dolby* inputs and outputs permit connection of an outboard
Dolby noise reduction unit, for example, to receive
Dolby-encoded FM programs.
Two tape monitor circuits allow two tape decks to be used
for recording, playback and tape-to-tape duplicating.
Microphone inputs on the front panel let you use the SX-1010
as a public address amplifier.
Audio muting switch decreases the volume instantly by 20dB
without having to turn back the volume control. Indicator
lamps light up in accordance with the functions used,
telling you at a glance what you’re hearing and how. Dimmer
switch dims illumination of tuning dial, tuning meters and
indicator lamps, leaving only a softly glowing light in the