Yamaha a 760 schematic

Page 1

A-760 A-760

I ADJUSTMENT Power Supply voltage I BLOCK DIAGRAM
U.S.A. and Canadian : AC 120V

Prior To Adjustment ' General :AC 115V new man:
0 Idle the unit for about 5 minutes before adjustment. North European 5 AC 220V ©
Australia and En REC 0UT lNFUT TONE AMP HIGH PURE
British : AC 240V swlrcn swnm none FILI'ER EVrgfiR
- . to
sm ION-ix lvnoiscnow n 1
' - . . . . Measuring MON0 lZdB/ucl E h- Step Item Condition Adjustment Test Point Specrfication Instrument . o L-
.
l
. i
idling cur- . . Main board (1) "low SWITCH : R
, VOLUME mini- TP - P D' ital volt- TREBLE . g l
1 rent adjust- mum position VR303 (L-ch) TP :P: 1:) 10 i 5mV mlegter : Lo
adjustment VR304 (Fl-ch) 3 © TUNER , l : L_l
Aux l
Offset , , Main 0 r l
VOLUME min.- b a d (1) TPs-TFs lLl TAPE FBI
2 voltage , . VR301 (L-ch) 0 i10mV Same as above L| TENN v 3
, mum position TPv-TPa (R) PE 2 >- s 0 LE 5'- .
adjustment VR302 (R-ch) RECi MDN'TDR ;
- .
© R502 . PRUTECTlON E
Main t B . . 1
3 volta 9 Non load Main board (1) Control board P1 terminal I Digital volt-
. g VRSDS , - Chassis earth meter ' POWER swrrcn
adjustment . _°
+ B n
Photo- Across P: and TPs on the control board (If the voltage is Hume" WNSTANT
ecu-paler VOLUME mini- outside the specification, adjust VRSOl on the control E
4 current mum position; board and VR305 on the main board alternately until the 1.2V 1 0.2V Same as above -EL -52vconsrmr
check non~load 1 B voltage and the voltage across Pi and TP3 are within 3'?
the specification.)
. FEED BMK
*" U.S.A. and Canadian, General 47.5V i 0.3V
N. European, Australia, British 47.0V io.3V . - .
Main c.Board _. ., .- SPECIFICATIONS
Minimum RMS Output Power Maximum Input Level (1 kHz) Headnhnne Output .......... 6.5 MW (8 ohms.
5 ohms, 20 m 20,00on 0.01% THD Phone MM. . '50 mV RMS MW» THD!
- ~ - . 3° W + 30 W '0'? MC - . 3 "V M5 Sumicnnducton ....... . . . . 47 Transistors, 4 le,
(D'Nl ------- - 1° W 0 W Tana Connor Chum: tics a FETs, 54 Diodes.
Total Harmonic Ditto Bass . :10 as at 20 Hz 3 LEDs
120 to 20,000 Hz) Treble} , - 20 d5 5 '10 kHz Power Supplies
+3 voltage check P_°|MS mm M 0 "a 0* 5 V 9" Turnover Frequencies Bass . . , 500 Hz u.s_ and Canada . . izo v, so Hz
lcollector=heat smk) Ph MC a -B- 159- ,. 0313035" Treble . 3.5 kHz General. . . llU-IZO v12207240 v,
n t l I K
_a __ ° ° o a": _ u .. 4 finger) . Output Level/Impedance Nmmm Em 2363120 H1
Idling current Aux/Tape/Tuner to so out 140 w . Rec 0|" ---------------- 50 "'V/550 hm 5m. and Austral-.5 240 v, 50 H,
adjustments .......... 0.005% SignaI-to-Noiu Ratio Pow" Comm .
. Nlon
_ IM Distortion Ratio (60 Hz: 7 ka=4 : ll HF A WW! "Wm 5mm") us. and Canada . . . 350 w/aaa VA
C t I C B d (1 Off set voltage mam/TUWDSF 0"" PM MMuomv) ' 5 General. ,. . 350w
on ro . oar I TR327 . adjustmenm TR328 . Bonms,40w.. . .. 0.002% * ' 0" M9l5°°Wl~ ~ 75 Britain Airslraliaand
-_l_ '-" VR303 VR504lR - sonms, l w. . ... .. 091% Wm/"rm" 5 "Vl- w 03 '35 Noni. swam _ ,, . 520 w
' @L VRSO VR302 Q Q Power B-nflwidm mm" m ammo"; in N a D) , . 435 x n2 x 355 mm
(L) (R) (IHF A Network) ......... 165 uv . .. . n
B | {a ehms,4DW,D,02% THDl (171/3 K47/l6 x
i vo tage .......... 10m 50 000 Hz p. i. - . i4-3/8">
® __ . itarc aractensllcs
adiustment i: pm in Fm » High .................. leHz, i2 dE/oct. . a. k 20 ",5. 7
E! D 9 nght. . .............. gt . )
(3 ohms, 1 kHz) , . Better than 55 channel smmim
D n ' . Frequency Response (1 kHz, vol. -30 d3. Shorted)
sz [Aux/Tapa/Tuner in SD 0m, 3 ohms) Tuner to $0 Out . . . 70 03
__J a _ , 20 m 20.000 H, cg) Phone MM to Sp on, 70:13
Photo-coupler TR329 AA Malian Phone me to SD om . , 70 as
current check Phonu MM .............. :02 as Continuous Loudness Control
- Phone Mc .............. 20.3 as iszeI-Reiataa Equalization)
Inws'mmviy/[mwdam Max, Attenuation ......... zoaaai I kHz
V 50' --\ Phone MM . . 2.5 mV/47 k ohms Gain hacking Error (0 [0 -so as)
Phona MC . . . 250uV/100 ohms , , . . 2 as Spear/iamansm/m to change withoutnatice.
TP3 Aux/TaDe/Tuner. . 150 «MM kohms
m -B voltage check point
Pl P2 (collector=heat sink)
Control C. Board (2) FRONT
TP3