Page 1
AU-
517/717
1. SPCIFICA TlaNS
AU-717
Power output
Min. RMS, both channels driven, from 20 to 20
000 Hz, with no
more than 0.025% total harmonic distortion
85 watts per channel into 8. ohms
Load impedance.
. . . . . . . . 8 ohms
Power bandwidth. . . . . . . . . . . . .
20 to 20
000 Hz at or below
rated min. RMS power output
and total harmonic distortion
Total harmonic distortion
(POWER AMP IN) .....................
less than 0.025% at or below
rated min. RMS power output
Intermodulation distortion (70 Hz: 7 kHz = 4:1 SMPTE method)
'...........,.... lessthanO.025%
Frequency response (at 1watt) (POWER AMP IN)
..................,.. Oto200OOOHz+OdB-3dB
RIAA curve daviation
(PHONO) . . . . +0.2 dB -2 dB
(20 to 20000 Hz)
approximately 60 at 8 ohms
load Damping factor. . . . . . . . . .
Input sensitivity and impedance
(1 kHz, for rated power output)
PHONO "
" 2.
5mV/47kilohms
(Max. input capability; 350 mV at 1 kHz
, less than 0.01 % total
harmonic distortion)
AUX, TAPE. . . . . . . . . . . . ..
150mV/47 kilohms
Output level (1 ,000 Hz)
TAPEREC(pinjack) "
150mV/47kilohms
PREOUT...............
1V/47kilohms
Channel separation (1 kHz
, at rated power output)
PHONO "
betterthan60dB
AUX..................
betterthan65dB
Hum and noise
(short-circuit, A-network)
PHONO ..........
78dB
AUX..............
100dB
Controls
BASS. . . . . . . . . .
Tone selector
TREBLE ...........
Toneselector...........
SUBSONIC
FILTER.........
HIGHFILTER............
MUTING. . . . . . . . . . . . . . .
LOUDNESS (-30dB) .,.:!:10dB (50 Hz)
200400 Hz
:!:10dB (15kHz)
, 6 kHz
3dB(16Hz),
6dB/oct
3dB (10kHz),6dB/oct
20dB
9dB at 50Hz
7dBat10kHz
Power requirements
Powervoltage............. 100
, 120220
240V (50/60Hzl
120V (Usable 110 - 130V)
60 Hz (for U.A. & Canada
only)
Power consumption
Maximum consumption. . . . . . .
Rated consumption. . .
Dimentions................
Waight . . . . . . . . . . . . . . . . . . .
735 watts
425 watts 500 VA
430mm (16-
15/16") W
168 mm (6-5/8") H
389mm (15-3/8") D
8kg (39.2lbs) net
19.8 kg (43.7 Ibs) packed2.
BLOCK DIAGRAM
r----____n
:r:t: I
UUI
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--' a: I -"' """ ~~,, . , "-"-,
0.. I
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0.. I
Ln_____-0 ~
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7'"
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t --------_:_---------+ _
:i!!:i!!, - $; ~'"" ~ ';; ~~: , , , "- "- ,----.,.
n_____------
_n_______n__-,'j ,- - - - - -- ';",
"'I
":"1
0..
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:51
,21
L______---- --- -----,,-------
IIA
JlI'-
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II,
JI'"
I:~
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"(0 "'"
d ..:.. - - - - -- ---
JL______-n__----_n----------
ttJ~
r--------- ------------------------- -- - .. ~:
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~I
"gl
=1
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L______- - ------------- -- - -- - -- -----_
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i'i~ ~ ""
L__- -- - -- --- ---- --~ -~--~--_!_--_
Page 2
AU-
517/717
3. ADVANTAGE AND OPERATION OF
POWER AMPLIFIER CIRCUITRY SECTION
DOl
ZDOI
FETOl" ...'-'
ZDO2
1. Advantage
OThere is neccessity not to decrease the phase response till
DC range in order to increase the music signal response of
extremely low frequency range. Therefore, this amplifier is
employing no capacitors except ones for phase compensa-
tion, and has an almost perfect transient characteristics.
0 The first stage FET (2SK9?) is a dual FET of even characteris-
tics and has a large Gm and no-leakage current at normal
temparature.
To avoid the influence by temperature drift
, such as center
voltage (OV) deviation
, this FET is used as differential am-
plifier and operates at cross point which is the
optimum
point of drain current (at about
3mA) against the tempera-
ture drift.
OTransistors, TROS and TRO?
, the push-pull pre-
driver stage
functions as current differential amplifier that the stabilized
operation can be obtained. In addition
, the collector cur-
rent of these transistors is enough high to make
linearity
excellent.
OSince this Amplifier employs phas~ advancer circuits (CO6
COB, C1S, R29
, C16 and R30J, which have not
been fre-
quently used
, to
compensate the phase characteristics on
high frequency range and is also made to
have enough
4. ADJUSTMENTS
1. Driver Circuit Board Adjnstments
Note: 1.
STEP IMaster Volume.... ........ ........
Minimum
RoomTemperature................
SUBJECT I EQUIPMENT
I MEASURE OUTPUT Icurrent on each stage to increase the through-rate
, the
performance on high frequency range is conspicuously
improved.
OTo avoid the voltage deviation, regulated power supply
circuit composed of ZDO1, ZDO2 is employed.
2. Operation
The use of differential amplification at first stage dual FET
(FETO1, FETO2) and connection of the FET to the
differential
amplifier composed of TRO1, TRO2
, make possible to obtain
enough gain and remarkable low distortion.
The output signals of TRO1 and TRO2 are untiphase.
The output signal of
TRO2 adds to TROS
, on the other hand
the output phase of TRO1 is inverted by TRO3
, then, it becomes
input signal of TRO4 and TRO? which are cascoded connection.
The output signals at
TROS and TRO? are
inphase that the op-
eration of this stage is push-
pull drive and current differential
amplification. The power amplifier of the final stage is com-
posed ofSEPP
(Single Ended Push-Pull) symmetry comple
mentary in 3-
stage darlington connection type.
TRO9 and TR10 are
composing current limiter circuit to protect
power transistor from break-
down by overload.
(See
the picture of top view on page
3. For adjustment, run the unit for more than 3 minutes after
the power is switched on.
ADJUST
ADJUST FORCONDITION
DCOVDC Volt MeterSpeaker TerminalF-2721DC OV:tSmV0 Set VRO1 and
VRO2 to center
L-CHVRO1, VRO2
position.
0 Then
, for the purpose of pro-
DCOVSame as aboveSame as aboveF-2722DC OV:tSmVceeding the accurate adjust-
ment, set the voltage to 0 volt
VRO1, VRO2
by VRO1 first and VRO2 next.
Bias CurrentSame as aboveTP Terminal (+) (-)F-2721DC 20mV:t1mV0 By turning
VRO3 counterclock-
of F-2721VRO3wise, the bias current is de-
creased gradually.
Bias CurrentSame as aboveTP Terminal (+) (-)F-2722DC 20mV:t1mV
of F-2?~VRO3
