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the
amplifler chassis and rover can be made of
m agnellc materials, so It can shield the amp from
effe<:tS of both external electromagnetic fields
and e4ectrostatlc charges; the amp may be
placed side-by-side or stacked with any other
audio components.
Three-Dimensional Analysis (3D A)
Reveals Outstanding Performance
The SE-AS's superior performance becomes
obvious when illustrated with the Technics 3DA
graph (back page). This visual device was deve
loped by Tec hnics for use with amplifiers, and
shows distortion measurements on the order of
parts per million (ppm). At Its rated output of
120 watts per channel, the THO of the SE·AS is a
mere 0.002% (2(}-20,000 Hz, 8 ohms), and
remains within 0.002% even with an output as
low as 250 mW. The 3DA graph also shows ihe
extremely wide power bandwidth. 5Hz to
100 kHz with less than 0.007% THO.
Independent Left and Right Channel
Power Supplies
Obviously, rugged, heavy�u1y performance Is a
must in power amps. The Impedance of speaker
systems varies from 4 to 16 ohms. nominally.
And even 8 ohm speakers connected in parallel
(A+ B) will present a 4 oh m. so it is easy to see
the importance of solid construction In power
amps. To satisfy this variety of load require
ments, the SE·AS is equipped with Independent
power supplies for the left and right channels
using four 10,000 11F high capacity electrolytic
capacitors. The powerful power supply and large
heat sinks are able to sustain 160 watts per
channel, both channels driven Into 4 ohms from
20-20, 000 Hz, with no more than 0.003%
THo-performance is always outstanding,
regardless of the speaker configuration (within
the specified 6mits of the amplifier's capability).
Output Power Selector Switch
One ol the special features of the SE ·AS Is the
output power selector switch. In the FULL
position, full rated output ol120 watts per
channel may be obtained. In the LIMITED
position, output power Is restricted to a more
modest 30 watts per channe4, retaining all the
benefits of high power reserve. yet providing the
same ultra -low distor tion and excellent
frequency response as in the full position. This
feature allows the unit to be used at reduced
power levels at night or whenever it is not
possible or practical to use a full 120 watts of
power (this can be a great money-saver for users
who prefer to leave their amps running at all
times-the idle current's pow8f' consumption Is a
mere 33 watts). The LIMITED position also
extinguishes the meter IDumlnatlon for additional
power savings.
Other Features
-Fully electronic protection circuit protects the
speaker systems and power amp In the unlikely
event of DC potential appe aring at the speaker
terminals. A re4ay acts to protect the amplifier
from a short circuit across the speaker
terminals or when an extremely low impedance
load Is encountered.
-Large power meters give direct readings from
0. 000 1 W to lull power. Meter response Is
based on BTS specifications and meter
indication closely matches the VU type.
-Floating coil power transformer for low hum and
low magnetic flux leakage.
-SIN ratio of 123 dB with very low residual noise.
-Current surge protection circuit. Peak current is
not reached until a few seconds after power is
turned on.
-Easy-to-connect speaker terminals.
-Distinctive heavy-duty die-cast panels.
-Durable, gold-plated input terminals and
connectors on acc essory cables. SU-A6
Stereo
DC Control Amplifier
Class A Circuitry Throughout ... Low
Noise FET Differential Inputs Eliminate
Capacitors
The Tech nics SU-A6 Is a high perfor mance
preamp which can be used with any high fidelity
power amplifier. h employs class A circuitry from
input to output, and FET differential inputs in all
stages for complete input capacitor-less (ICL)
circuitry. Basic circuitry consists of the high-gain ICL
phono equalizer amp, ICL DC fiat amp, and DC
output amp.
Only one coupling capacitor is used (at the
phono equalizer output), making this amp
capable of straight DC amplification from high
level inputs (tuner, aux. and tape) to output.
Parallel Low Noise FET ICL Phono
Equalizer Amp
Technics SU-A6 consists of two ultra-low noise
dual FET differential amps connected in
parallel -these form the first stage of the phono
equalizer. Thus, phono EO is input capacitor
less for extremely low noise. The high-gain
phono equalizer Is capable of direct MC cartridge
connection and gain Is simply reduced for
compatibility with MM cartridges. Phone SIN
ratio is 79 dB for MM cartridges (IHF 78). and
76 dB lor MC cartridges (IHF "78)-these f�gures
of fer outstanding performance for a preamp in
t his price range. And with an AIAA deviation of
:!:0.2 dB (20-20,000 Hz).it Is obvious that the
SU-A6 has been designed to please the most
discriminating listener. Plus, linear response Is
maintained all the way up to 100 kHz (±0.5 dB).
This high performance equalization means that
even square wave inputs may be reproduced
with a high degree of accuracy.
Phono Equalizer Noise Spectrum
High-Gain FET DC Aat Amp and Single
End Push Pull {SEPP) Output Amp
The flat amp and output amp are pure DC amps
without a single capacitor in the signal path.
When used with a DC power amplifier, the
SU·A6 will al low DC amplifiCation which extends
all the way to the speaker terminals.
Utilizing an SEPP output amp reduces the output
impedance to an extremely low 2 ohms. Thus,
the length of the power amp connection cable
does not affect system performance, allowing
the power amp to be placed far from the
preamp. And a rated output of 2 volts is sufficient to
drive even the lowest sensitivity amplifiers with
ease. The power supply consists of two sets of
balanced outputs with stabilized current load,
and Zener diodes with superior thermal
characteristics limit DC drift to an absolute
minimum.
4-Ganged Volume Control
The volume control
is2·gangedfor each channel
(located on both sides
of the
flat amp) for a
4 -ganged master vOlume control. It prevents
noise when the volume Is turned down and
improves the overall SIN ratio.
Top Performance with All Cartridges
The SU·A6 1s equ ipped with two phone input
terminals. Phono 1 has fou r positions and may
be used for low output MC, high output MC. low
output MM. or high output MM cartridges. With a
single selector switch, compatibility with any
cartridge is available, eliminating any chance of
a mismatch between the cartridge output and
preamp input sensitivity while also providing
excellent SIN ratio. MM cartridge input
i mp�ance
Is 4 7 kilohms. and 100/220 ohms for
MC cartridges
depending on the MC input
selection.
Shelving Tone Controls
To obtain outstanding low and high frequency
response with today's audio systems and source
material, you may need more equalization facili
ties than are included on most conventional pre
amps. Technics· unique type of shelving tone
control satisfies this require (llent. It consists of
steep slope Super-Bass and Super-Treble con
trols, plus a regular gentle sjoping bass and
treble configuration, rovering a wide range.
These four controls can be used in combination
to provide a wide range of equalization charac
teristics. In recent years, people's taste has been
leaning toward deep bass reproduction. With
only a conventional bass control, many speakers
have been over-<:ompensated in the mid bass
range (which resuhs in boorn y, unrealistic
sound), but still poorly compensated in the deep
bass region. Boominess. even if caused by poor
listening room acoustics or speaker position. can
be effectively controlled by attenuating the
gentle sloping bass. and turning up the Super
Bass controls.
Shelving Tone Control Characteristics
