Hitachi HA-6800 Service Manual

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© SERVICE MANUAL
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TY No. 289EGF
HA-6800
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CONTENTS —~
SPECIFICATIONS ........:.ccccee cee eeeuneteeeeseeesnenenee 1
FEATURES: cncccesiiccesin cnvdcieite Celene Gis sa MAGEE KeasRRW 3
DISASSEMBLY AND REPLACEMENT .............. 3
SERVICE POINTS. occ ccecccseuia swawicissans o0i vans cae meitneres 4
A DIUST MENT inc cea cas pastinvey naa yeviaronie stan tee oisiee Gecochernayeraie 5
DESCRIPTION OF THE NEW CIRCUIT .............. 6
BLOCK DIAGRAM ........0:cccccccneeeteteeenenesesneneees 8
PRINTED WIRING BOARD ..........:::cceeeseeeeeneeee 9
CIRCUIT DIAGRAM ...........:. ccc ccee scene eee eeneee een 11
CHECKING THE OPERATION OF THE
PROTECTION CIRCUIT ...........::cceceeeecn snes eae ees 12
REPLACEMENT PARTS LIST ..........:.ccceeeeeee eee 16
FRONT AND REAR PANEL
SAFETY PRECAUTION
The following precautions should be observed when servicing.
1. Since many parts in the unit have special safety related characteristics, always use genuine Hitachi's replacement parts. Especially critical
parts in the power circuit block should not be replaced with other makes.
Critical parts are marked with A\ in the schematic diagram and circuit board diagram.
2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain that it is completely
safe to operate without danger of electrical shock.
SPECIFICATIONS
" Measured pursuant to the Federal Trade Commission's Trade Regulation Rule on Power
Output Claims for Amplifiers.
POWER output
(Both channels driven)
70 watts* per channel,
min. RMS, at 8 ohms from
20 Hz to 20 kHz, with no
more than 0.008% total
harmonic distortion.
75 W/ch + 75 W/ch
(8 ohms, 1 kHz, T.H.D. 0.004%)
75 W/ch + 75 W/ch
(6 ohms, 1 kHz, T.H.D. 0.004%)
Power bandwidth 5 Hz-- 100 kHz (T.H.D. 0.05%)
Frequency characteristics
TUNER, AUX, TAPE 1, 2
PHONO .
Harmonic distortion (8 ohms)
(at rated output)
(at 1/2 rated output)
Intermodulation distortion
(at 1/2 rated output)
Input sensitivity/Impedance
PHONO MM 2.5 mV (47 k-ohms)
MC 0.15 mV (100 ohms)
150 mV/40 k-ohms
150 mV/40 k-ohms
1 Hz—200 kHz (+0, —-3 dB)
RIAA +0.2 dB
Less than 0.008%
Less than 0.008%
Less than 0.006%
TUNER, AUX
TAPE PLAY 1, 2
Output level
TAPE REC OUT 1, 2
Phono over toad level
{at 1 kHz, T.H.D. 0.01%)
Signal-to-noise ratio
(IHF, A network}
PHONO
150 mV
MM: 250 mV, MC: 15 mV
89 dB (MM) 73 dB (MC)
(input level 0.25 mV)
TUNER, AUX, TAPE 1, 2 100 dB
Damping factor 60 (1 kHz, 8 ohms)
Bass control +8 dB (100 Hz)
Treble control +8 dB (10 kHz)
Loudness control +6 dB (100 Hz)
+4 dB (10 kHz)
16 Hz (6 dB/oct)
AC 120 V 60 Hz, 220 Y 50/60
Hz, 240 V 50/60 Hz or +120
V/220 V/240 V 50/60 Hz
430 VA, 300 W (at 1/3 1a ted out-
put)
500 W (at rated output)
435 (W) x 145 (H) x 392( D) mm
12.5 kg
Subsonic filter
Power supply
Power consumption
Dimensions
Weight
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.
STEREO AMPLIFIER
October 1981 TOYOKAWA WORKS