Sansui QS 500 Brochure

Page 1

4-CHANNEL REAR AMPLIFIERSEE

Mimi]

Ell ' . FRONT BALANCE

, ; ' . Ion

i LEVEL 5:! mt MW A I .
i? am VOLUME \

a REAR SPEAKERS Li" I I!

Am

bum) '9

SANSUI QS-SOO 4-CHANNEL REAR AMPLIFIER Youre looking
at what has to be the best bet yet for 2-channel stereo owners with 4-
channel ambitions. It's the all-new Sansui QS-SOO 4-Channei Rear Am-
plifier-a feature-packed power amplifier/4-Channel Synthesizer Decoder
combination designed to let you parlay your present 2-channel system
into a thoroughbred 4-channel system. Overnight. And to do so with
maximum economy. Here's what you get: a powerful 120 watt high-
performance power amplifier plus Sansuis unique 4-Channel Synthesizer
Decoder. And heres what it means to you: instant capability for con-
verting your present 2-channel tapes, discs (and FM stereo broadcasts)
into the immensely richer 4-channel format. The result is a very, very

DER

R DECO.

SVNTHESLZ'GEM/erw
«M ,5:

vowME anew w
I

0:500

In
3

MAIN BALANCE

Kill

_ w... ' 4.....~_ , .t.-...;:mu»~..-u.-...s(«wags .

close approximation of vibrant sound fields as they are experienced at
live performances, with all the same liveiiness and excitment. With the
(25-500, you need only add a second set of speaker systems to your
present setup, and youre off and running. And the effect is even more
overwhelming when you hear two-channel records, tapes and FM stereo
broadcasts encoded from four channels by the Sansui 4-Channel En-
coder. Another attractive feature of the 03-500 is that it provides for
recording and playing 4-channel stereo tapes should you aiready own
or plan to buy a 4-channel stereo tape deck. The Sansui 08-500. A
brilliantly-engineered component that carries you in one giant step into
the new, breathtakingly beautiful world of 4-channel sound.

lauds u.

Page 2

THE SANSUI QS-SOO 4-CHANNEL REAR AMP-
LIFIER AND 4-CHANNEL STEREO: Four-chan-
nel stereo is the most advanced means yet
devised of faithfully reproducing an original
sound field. Two-channel stereo has reached
the limit of its potential in this respect. re-
stricted as it' is to merely reproducing sound
sources points IFig. 1I. By moving up to 4-chan-
nel stereo with the Sansui 4-Channel Rear Am-
plifier QS-SOO you are not merely doubling the
stereo effect as you might suppose, but rather
you are multiplying the effect many fold to ap-
proximate a sound field as it would be experi-
enced in a concert hall (Fig. 2I. In other words,
you are moving from a sound sources point
method of reproduction to the reproduction of
an entire sound field. This is made possible by
the Sansui QS-SOO's capability of handling re-
flected or indirect sound. in addition to direct

sound as an independent sound source.

(Fig 2I

ii Ls. '. L -L. hemp...» Leaf.

SOUND FIELD: By sound field we mean all of
the sounds that you are exposed to in a live
performance-not only those coming directly
from a stage-but those far more numerous
indirect sounds which are reflected by the ceil-
ing, walls, floor and furnishings as well IFig. 31.
The extra set of speaker systems in the 4-chan-
nel stereo format gives the resources needed
for reproducing a great deal more of such
sounds and to approximate for the first time a
sound field in the living room. Besides the
second pair of speaker systems. you need only
add the 08500 to your present 2-channel sys-
tem to achieve the new 4«channel stereo sys-
tem. And while it may be a few more years be-
fore standardized 4-channel stereo records and

M.

(Fig. 3)

If??? R? ~

VIII" jxv n;

FM broadcasts become available, the 08- 500
offers the immediate advantage of converting
existing 2-channel program sources to the new

SPECIFICATION
POWER AMPLIFIER SECTION
POWER OUTPUT
MUSIC POWER (IHF) 120W at 49 load
90W at 89 load
CONTINUOUS POWER 40/40W at 49 load
33/33W at 8!) load
TOTAL HARMONIC DISTORTION
less than 0.57° at rated output
INTERMODULATION DISTORTION
(60Hz: 7.000Hz=4: 1 SMPTE
method)
less than 0.5% at rated output
POWER BANDWIDTH (IHF) 20 to 40 OOOHz
FREQUENCY RESPONSE (at normal listening)
20 to 50,000Hz 1 MB
CHANNEL SEPARATION better than 60dB
HUMIND NOISE (IHF) better than 80dB

LOAD IMPEDANCE 4 to 169
DAMPING FACTOR 24
CONTROLS

VOLUME

LEVEL SET

FRONT BALANCE (LEFT-RIGHT)
REAR BALANCE (LEFT-RIGHT)
MAIN BALANCE (FRONT-REAR)

4-channel format. This is done by letting the
second pair of speaker systems take over much
of the sound burden formerly borne by one pair
alone. The two pairs are then repositioned so
that indirect sounds and extreme end sounds
are processed through the QS-500's decoding
matrix before being emitted through the rear
speaker systems, for a remarkable increase in
liveliness and presence.

HOW THE 05.500 WORKS. The QS-SOO more
closely approximates such a sound field than
any other system yet devised. It accomplishes
this by singling out indirect sound components
from 2-channel sources by the use of the
Sansui-developed QS decoding matrix, shifting
their phases to achieve complete 2- to 4-chan-
nel conversion, then finally modulating their
phases anywhere from 0 to 180 degrees to
create the apparent effect of emitting sound
from numerous directions IFig. 4). This results
in a revolutionary increase in the sense of pres-
ence, giving you the same feeling you'd experi-
ence at a live performance. Further, if you were
to reproduce 2-channel discs recorded with a 4-
channel encoding matrix, the decoding matrix
would separate the two channels back into the
original four channels, enabling each speaker
system to establish distinct sound images of
the particular sound sources assigned to it dur-
ing the original 4-channel recording session.
We call this capability of the OS decoding ma-
trix to separate encoded' 2-channel material
back into four channels its decoding function.

Ewing-h, :1", w-u 7,7737 lllfljh'fp'val-Y'

QS DECODING MATRIX: This )5 the first step
on the way to converting 2- channel sound
sources into the immensely richer sound of 4-
channel stereo. To understand itfully, imagine
an orchestra on stage. The two recording micro-
phones in 2-channel stereo are normally spaced
on either side of the center of the stage. Be-
cause of the limitations of this 2-point pickup
arrangement, all the direct sounds (those which
reach the microphones directly), indirect Ithose
reflected by walls, ceiling, floor, etc., before
reaching the microphoneSI and direct independ-
ent (those produced at the extreme ends of the
stage) are randomly mixed and delivered as

SWITCHES
SYNTHESIZER/DECODER 2-CHANNEL, CONCERT
HALL-1. CONCERT HALL-2,
SURROUND
NORMAL. QUARTER-TURN,
HALF-TURN DECODER
TAPE MONITOR (2-CHANNEL) SOURCE, PLAY BACK
(4-CHANNEL) SOURCE, PLAY BACK
POWER/SPEAKER POWER OFF, SYSTEM-A.
SYSTEMB, SYSTEM A+B.
SYNTHESIZER SECTION
INPUT LEVEL
RATED INPUT (2-CHANNEL) 0.15V (SOKQ)
MINIMUM INPUT (2-CHANNEL) 0.05V (SOKQ)
TAPE MONITOR (2-CHANNEL) 0.15V (50KB)
(4-CHANNEL) 0.775V(50K9)
OUTPUT LEVEL
RATED OUTPUT (OVU) (4-CHANNEL)
0.775V (to Front Amplifier)
MAXIMUM OUTPUT (4.CHANNEL)
5.0V (to Front Amplifier)
RECORDING OUTPUT (2-CHANNEL)
0.15V
(4-CHANNEL)
0.775V

lump left and right channel signals. Sansuis
QS decoding matrix takes these lump signals
and reorganizes them. Now instead of having a
mixtureofdirect,directindependentandindirect
sounds, there is a separation of these compo-
nents. The direct sounds are sent ahead for
reproduction by the front channels, while the
independent and indirect sounds are phase-
shifted to render them identical in phas d
establish clear sound images in the rear c....n-
nels as well. These sounds are then phase-
modulated and reproduced from the rear speak-
er systems IFig. 5). This, we call the sound
field synthesizing function of the Q5 decoding
matrix.

I J
l.
N x
.' 8 ~ "

. '- I. E
,. $0.1 <
L - _ . 5 __ Phase Phase
i' - g g Shifter [T Modulator
5R 5

:0- ° .

i 9 u __ Phase __.Phasa '__°Rur .
l N g Shifter Modulator RIIIII _

. c..=...~.....x ;-us..;-;..u...t.s.il

PHASE MODULATION: As the illustration
shows, the Q8 500 takes the rear channel sound
components-shown here as a regular pulse
form-and through its unique process of phase
modulation, gives it increased depth and rich-
ness without requiring an increase in power.
The principle is easy enough to understand: As
the rear channel sound components are phase-
modulated from 0 to 180 degrees, sounds come
out of the rear speaker systems with minute
phase differences. This means, as Fig. 6 shows,
the sense of sound volume dramatically in-
creases, especially expanding the dynamic
range of percussive sounds. Simultaneously,
since the rear channel sounds now arrive at the
listeners ear with fine time delays, the end
effect very closely approximates the acou-ic
effect present in an actual concert hall a
the original sounds are reflected by the ..s.
floor, ceiling etc. and converge upon the listen-
er's ear with various time delays. This gives us
a great increase in presence'. and is the most
important aspect of the 4-channel stereo effect
made possible by the ossoo.

r vy} ta 1 y" mtrfiii

FREQUENCY RESPONSE

FRONT CHANNEL 20 to 20.000Hz ildB

REAR CHANNEL 20 to 20.000Hz :- 1dB
SYNTHESIZATION OF REAR CHANNEL SIGNAL

1 NEW SANSUI'S MATRIX SYSTEM

2 PHASE MODULATION SYSTEM
REAR CHANNEL PHASE SHIFT

(LEFT) 90 degree at 3OOHz
(RIGHT) 90 degree at 600Hz

REAR CHANNEL PHASE MODULATION
Max. 180 degrees at 10.000Hz
(by Sansui's phase modulation
system)
HUM AND NOISEiIHF) better than 70dB
GENERAL
SEMICONDUCTORS

Transistors: 37 Diodes: 12 IC: 1 Modules: 7

Zener Diodes: 2
POWER REQUIREMENTS

POWER VOLTAGE 100, 110. 117, 127, 220, 230
240. 250.
POWER CONSUMPTION 205W(max. signal)
DIMENSIONS

382mm(15}fi')Wx 162m m(6%')H x 337mm(13%')D
WEIGHT 10 Kg (22 lbs).