Sansui Patented
Digitally Quartz-Locked FM/AM Stereo Tuner with Impeccable Drift-Free Tuning
Accuracy.
FM Fronted
Sensitivity; Enhanced by low-noise Dual-Gate MOS FET and 5-gang Tuning
capacitor
The extraordinary
tonal quality of the Sansui TU-919 begins here. Crossmodulation and
interference are avoided in the FM fronted using a low-noise Dual-Gate MOS FET
RF amp and a wide-gap, frequency-linear 5-Gang variable capacitor of high
precision. The 50 dB Quieting Sensitivity is an excellent 13,5 dBf (mono) and
35,5 dBf (stereo)
FM IF Selectivity;
Very low group delay means much-improved sound.
Tonal quality is
further enhanced by flattening transient group delay and phase distortion to
achieve higher selectivity with lower distortion in the FM IF section. The real
test of our IF circuitry comes when inputs from your antenna vary unpredictably
in level.
Actual field tests
show the effectiveness of the ten differential IF stages, contained in one
Darlington-connected differential IC, and the linear-phase ceramic filters
found here. Changes in signal level have hardly any effect on selectivity.
Patented Variable
Group-Delay Equalizer; Distortion is further reduced
This is a unique
device that permits the independent adjustment of the equivalent amount of
Frequency Response of the IF signal within the bandwidth. This, in turn, helps
eliminate any deviation, however minute, in group-deley response within the
bandwidth. Higher Signal-to-Noise Ratio and lower distortion are also achieved.
FM Stereo Sound;
Wider separation and purer fidelity from PLL
Stereo FM broadcasts
are multiplexed with a "pilot" signal to trigger receiving tuners
into the stereo mode and enable them to "decpde" the composite signal
into left and right channels. Once its
job is done, that "pilot" (a 19 kHz signal) must be entirely removed
from the audio signal. The conventional filter used for this can cause more
problems than it prevents.
Such 19 kHz filters
are usually positioned at the output of the stereo demodulator. Together with
the "pilot" they also often filter out the upper end of the frequency
response and cause phase distortion as well. Sansui avoids such filters in the
TU-010 for a more musical sound.
Our stereo
dempdulator is a PLL type with a special "pilot" cancelling circuit
(not a filter) included in its IC. It eliminates the 19 kHz signal before it
enters the switching or demodulation stage. Output of the demodulator amp is
pure audio.
Wide-Range DC
Configuration; More guarantees of cleaner sound.
As in the highly
advanced Sansui AU amplifiers and our best Pure Power receivers, the DC
amplifier configuration in the TU-919 offers cleaner audio reproduction in both
AM and FM. Main advantages are; Wider dynamic range; Lower TIM distortion; and
Superb frequency response all are vital to hi-fi. These parameters are made
still more dependable by our reduction of the internal power-supply impedance
across the widest possible frequency range. Reproduction is always well
balanced.
Power Supply:
Attention given to better sound localization
An
error-correction/amplification constant-voltage circuit of an entirely new type
is found in the power supply of the TU-919. it provides unfailing power
regulation for constantly high performance quality. With impedance low
throughout, musical textures remain crystal clear and sound-image localization
in the reproduced sound field is the sharpest possible.
High-Power Drive
Ratio Detectr; S/N and linearity are improved
A newly-developed,
wide-range, high-power drive ratio detector, driven by a triple-base
Darlington-connected IC, is used in the FM discriminator. It contributes to
improved linearity and Signal-to-Noise Ratio. For more stability and still less
noise we've housed the discriminator in a shielded casing, separate from the IF
circuit.
Selectable IF Band
for AM; Wide/Narrow improves reception
By broadening the
signal-passing bandwidth in the AM tuner section, frequency range is
dramatically improved. For this reason, you'll want to use the Wide position on
the IF bandwidth selector. When the station to which you have tuned is strong
enough, the results in improved high frequency response are impressive. On the
other hand, weak or distant AM stations are received more clearly when you use
the Narrow position; the interference caused by stronger station broadcasting
on adjacent frequencies is dramatically lowered.
Sansui Exclusive FM
Digitally Quartz-Locked System; Contained in a single LSI
We've combined a
quartz crystal, providing a rock-steady reference base, with an error-free
digital control in the TU919. this Sansui-exclusive system detects any tuning
error caused by temperature, voltage and humidity changes and compensates for
it instantly. Drift is now a thing of the past. Most other quartz tuners use
analog phase reference controls that compare phase of two frequencies between
the local oscillators and quartz crystals. In order to check and correct errors
(drift). But our TU-919 doesn't instead it has a digital control system.
With it the
frequency counter samples the local oscillator's frequency constantly, once
every 0,01 seconds, timed by the accurate quartz. When there's an error, it's
converted to digital units, which are then converted to voltage to control the
local oscillator. When there's no error, the tuned frequency is locked to the
station's frequency.
Sansui's digital
processing doesn't use the kind of reference signal containing infinite
harmonics; therefore, we've eliminated drift without compromising spurious
response ratio, Signal-to-Noise Ratio sensitivity or other important
specifications.
There more features
make the Sansui system still easier to use. One, you need not remove your hand
from the knob to make sure the station is surely quartz-locked. Two, locking
range is wide, even rough tuning locks in the desired station and keeps it locked
for hours. Three, should you turn off the tuner a built-in Re-Lock system
memorizes your station for instant recall when you switch it on again.
Sansui has received
patents on our Quartz/Digital-Lock System. And to ensure long-term reliability
of its operation we've packaged it all in a single LSI with circuits equivalent
to thousands of discrete transistors, resistors and diodes.
Specifications
FM Section
Tuning Range: 88 to 108 MHz
50 dB Quieting
Sensitivity
Mono : 12,5 dBf
Stereo : 34,0 dBf
Sensitivity
Mono : 9,0 dBf (IHF), 0,95 µV (DIN)
Stereo : 15 dBf
Signal-to-Noise
Ratio
Mono : 83 dB at 80 dBf (82 dB at 65 dBf)
Stereo : 80 dB at 80 dBf (76 dB at 65 dBf)
Frequency Response
Mono : 30 to 15,000 Hz +0,2 dB -0,5 dB
Stereo : 30 to 15,000 Hz +0,2 dB -0,5 dB
Total Harmonic
Distortion
Mono : less than 0,06% at 100 Hz (0,04% at 1,000 Hz)
Stereo : less than
0,09% at 100 Hz (0,06% at 1,000 Hz)
Captire Ratio: 0,9 dB
Adjacent Channel
Selectivity
Wide : 5 dB at 200 kHz
Narrow : 18 dB at 200 kHz
Alternate Channel
Selectivity
Wide : 50 dB at 400 kHz
Narrow ; 80 dB at 400 kHz
Spurious Response
Ratio: 110 dB at 98 MHz
Image Response
Ratio: 110 dB at 98 MHz
RF
Intermodulation: 75 dB at 08 MHz
AM Suppression
Ratio: 60 dB at 98 MHz
Stereo Separation
40 dB at 100 Hz
50 dB at 1,000 Hz
35 dB at 10,000 Hz
30 dB from 30 to
15,000 Hz
Antenna Input
Impedance
Balanced : 300 Ω
Unbalanced ; 75 Ω
Output
Voltage/Impedance
Variable : 1 V/2,5 k Ω
Dolby FM : 200 mV/9 k Ω
AM Section
Tuning Range: 530 to 1600 kHz
Sensitivity: 47 dB/m
at 1,000 kHz (220 µV/m)
Selectivity: 35 dB at 1,000 kHz
Signal-to-Noise
Ratio : 50 dB
T.H.D. Less than 0,35% at 30% Mod. 80 dB/m
Image Response
Ratio: 70 dB at 1,000 kHz
IF Response
Ratio: 70 dB at 1,000 kHz
General
AC Outlets: Unswitched, total 100 watts
Power
Requirements: 100, 120, 220, 240 V 50/60 Hz
Power
Consumption: 22 watts
Semiconductors: 73 Transistors; 57 Diodes; 6 FETs; 16 ICs
Dimensions (W x H x
D): 430 x 168 x 402 mm (16-15/16" x
6-5/8" x 16-1/2")
Weight: 9,6 kg (21,2
lbs)
