Hitachi HMA-7500MKII Service Manual

"SAFETY PRECAUTIONS —
CONIENIS —_——————=sst—
SPECIFICATIONS ............. pee .
FEATURES .00.oo ieee ao 3
DESCRIPTION OF THE NEW CIRCUITS se 3
SERVICE POINTS oo... ccc cee ccceceansenee sent toe 8
PRINTED WIRING BOARD ............0.........0..5 11
CIRCUIT DIAGRAM ................0.ce ese eee ee eee 12
BLOCK DIAGRAM .............0.cecceceeeneeeeee> ao 13
ADJUSTMENTS ..... betes erie 13
CHECKING THE OPERATION OF THE -
PROTECTION CIRCUIT ..... oe eee te 18
TROUBLESHOOTING ..............0..0...00.. oo
DISASSEMBLY AND REPLACEMENT .......... 18
REPLACEMENT-PARTS LIST ......... es -—
The following precautions should be observed when servicing.
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ascertain that it is completely safe to operate without danger of electrical shock.
SPECIFICATIONS
Power output
(Both channels driven)
Power bandwidth
Frequency characteristics
Harmonic distortion (8 ohms) (at rated output)
intermodulation distortion (8 ohms)
(at rated output)
(at 1/2 rated output)
Input sensitivity/Impedance
Signal-to-noise ratio (IHF, A network, short circuited)
Damping factor (8 ohms)
Power supply
Power consumption
Dimensions
Weight
Specifications and parts are subject to change for improvement.
75 watts* per channel, min. RMS, at 8 ohms from 20
Hz to 20 kHz, with no more than 0.005% total .
harmonic distortion.
80 W/ch + 80 W/ch (8 ohms, 1 kHz, T.H.D. 0.005%)
80 W/ch + 80 W/ch (4 ohms, 1 kHz, T.H.D. 0.005%)
150 W (8 ohms, 1 kHz, T.H.D. 0.005%, BTL connection)
5 Hz — 100 kHz (8 ohms, T.H.D. 0.05% 1/2 Rated)
0.5 Hz — 100 kHz (+0, —1 dB)
Less than 0.005%
Less than 0.008%
'Less than 0.005%
1 V/47 k-ohms
118 dB
"700 (1 kHz)
60 (20 Hz — 20 kHz)
AC 120 V/60 Hz, ~ 220 V 50/60 Hz, ~ 240 V 50/60 Hz,
120 V/220 V/240 V ~ 50/60 Hz
420 W or 540 VA {at 1/3 rated output)
620 W (at rated output)
435 (VW) x 165 (H) x 320 (D) mm
14 kg
" Measured pursuant to the Federal Trade Commission's Trade
Heaviaven Rule on Power Output Claims for Amplifiers.
October 1980 TOYOKAWA WORKS