McIntosh MA-6500 Service manual
INTEGRATED AMPLIFIER
WATTS
2.0
20
-
20
-
10
DECIBELS
TUNER MUTEVIDEO LOUDPH AUX/TAP E
200
0
TREBLEBASS
0
0
4
LEFT RIGHT
SEN SOR
.
02
-
40
CD 2 MONO SPEAKERSCD 1
.
20
-
30
POWER OUTPUT
CONTENTS
Performance Specifications ........................................ 2
Notes ......................................................................... 3
Rear Panel .................................................................. 4
Section Location ........................................................ 4
Block Diagram ...................................................... 5 - 8
Interconnection Diagram .................................... 9 - 10
Input Driver Schematic and PCB ....................... 11 - 18
Heatsink Schematic and PCB ............................ 19 - 20
WATTS
2.0
-
20
DECIBELS
20
200
-
10
0
VOLUME
POWE R GUARD
HEADPHON ES
.
20
.
02
-
30
-
40
POWER OUTPUT
BALANCE
LR
1
2
Lamp Schematic and PCB ................................. 19 - 20
PG Display Schematic and PCB ........................ 21 - 22
Control Schematic and PCB .............................. 21 - 22
Tone Schematic and PCB .................................. 23 - 26
Parts List ............................................................ 25 - 28
Exploded View and Parts List ............................. 29 - 31
Repacking Instructions ............................................. 33
0
0
4
STANDBY ON
/
SERVICE MANUAL
PREFORMANCE SPECIFICATIONS
POWER OUTPUT, STEREO
250, 200, 120 watts minimum sine wave continuous
average power output per channel, both channels operating, into a load impedance of 2, 4 and 8 ohms respectively.
TOTAL HARMONIC DISTORTION
0.005% maximum at any power level from 250 milliwatts
to rated power per channel from 20Hz to 20,000Hz, both
channels operating.
INTERMODULATION DISTORTION
0.005% maximum if instantaneous peak power output per
channel does not exceed twice the rated output with both
channels operating for any combination of frequencies
from 20Hz to 20,000Hz.
OUTPUT LOAD IMPEDANCE
2, 4 or 8 ohms
RATED POWER BAND
20Hz to 20,000Hz
DYNAMIC HEADROOM
2.4dB at 2, 4 or 8 ohms
DAMPING FACTOR
60 at 2 ohms
120 at 4 ohms
230 at 8 ohms
FREQUENCY RESPONSE
+0, -0.5dB from 20Hz to 20,000Hz
SIGNAL TO NOISE RATIO, (A WEIGHTED)
Phono Input: 90dB (84dB IHF) below 10mV input
High Level: 100db (90dB IHF) below rated output
Power Amplifier: 110dB below rated output
SENSITIVITY
Phono: 2.5mV for 2.5V rated output (0.5mV IHF)
High Level: 250mV for 2.5V rated output (50mV IHF)
Power Amplifier Input: 2.5V for rated output
INPUT IMPEDANCE
Phono: 47k ohms, 65pF
High Level: 22k ohms
MAXIMUM INPUT SIGNAL
Phono: 90mV
High Level: 8V
POWER REQUIREMENT
120V, 50/60Hz, 5.0 Amps UL/CSA
230V, 50/60Hz, 2.5 Amps
PREAMPLIFIER MAXIMUM VOLTAGE OUTPUT
Phono: 90mV at tape output
High Level: 8V at tape output
Main Out: 8V at preamp output
VOLTAGE GAIN
High Level to Tape: 0dB
High Level to Main: 20dB
TONE CONTROLS
Bass Control: +/-12dB at 20Hz
Treble Control: +/-12dB at 10kHz
POWER REQUIREMENTS
100 Volts, 50/60Hz at 4.8 Amps
110 Volts, 50/60Hz at 4.4 Amps
120 Volts, 50/60Hz at 4.0 Amps
220 Volts, 50/60Hz at 2.0 Amps
230 Volts, 50/60Hz at 2.0 Amps
240 Volts, 50/60Hz at 2.0 Amps
NOTE: Refer to the rear panel of the MA6500 for the correct voltage.
DIMENSIONS
17-1/2 inches (44.5cm) wide by 7-1/16 inches (17.9cm)
high. Depth behind front panel is 18-1/8 inches (46cm)
including connectors. Knob clearance required in front of
the mounting panel is 1-1/8 inches (2.9cm).
2
NOTES
MA6500
1. The heavy lines on the schematics denote the primary
signal path.
2. Unless otherwise noted, all voltages indicated on the
schematics are measured under the following conditions:
a. AC input at 120 volts, 50/60Hz
b. All voltages are +\-10% with respect to ground. A
high impedance (10megaohm) voltmeter must be
used.
3. Unless otherwise specified:
a. Resistors values are in ohms.
b. Capacitor values are in microfarads (uF).
c. Inductor values are in microhenries (uH).
4. On PC Board Drawings, Square Pad Indicates:
a. Polarized Capacitors - Positive
b. Diode - Cathode
c. Others - Pin 1
5. The voltages enclosed in a box are signal voltages that
are measured with a 2.5mV, 1kHz signal connected to
both channels at the TUNER input jacks.
Front panel controls are set at:
BALANCE .................................... CENTER DETENT
TREBLE BASS .............................CENTER DETENT
INPUT SELECTORS...................................... TUNER
LOUDNESS .......................................................... OFF
POWER ................................................................... ON
VOLUME .................................FULLY CLOCKWISE
MONO................................................................... OFF
SPEAKER SWITCHES 1 AND 2........................... ON
Rear panel controls are set at:
PROCESSOR ........................................................OUT
PWR AMP INPUT ................................................. INT
SPEAKER TERMINALS .................... NO LOAD ON
OUTPUTS
6. WARNING:
Parts marked with the symbol have critical
characteristics. Use ONLY replacement parts recommended by the manufacturer.
3
WARNING
B
SHOCK HAZARD - DO NOT OPE N. FOR
CONTINUED PROTECTION AGAINST FIRE HAZARD
REPLACE ON LY W ITH SAM E T YPE AND RATING FUSE.
AVIS
RISQUE DE CHOC - EL ECTRIQUE - NE PAS
OUVRIR. REMPLAC ER PAR UN FUSIBLE DE MEME
TYPE, AM PERAGE ET VOLTAGE.
WARNING
RISK OF HAZARDOUS ENERGY!MAKE
PROPER SPEAKER CONNECTIONS.SEE OPERATING
MANU AL BEFORE USING.
AVIS
ENERGIE ELECTRIQUE DANGEREUSE! VOIR LE
CAHIER D’INSTRUCTION.
120V 50/60H z 4A
REAR PANEL
RIGHT RIGHTLEFT LEFT
M A 650 0 I N T E G R AT E D A M P LIF IE R
McINTOSH LABORATORY, INC., BINGHAMTON, NEW YORK MADE IN USA
SERIAL
NUMBER
T 10AL 250V
SLO BLO
EXT SENSOR
HEATSINK
PCB
POWER
CONTROL
DATA PORTS IN PU TS
VIDEO
TUNER
CD 2
SUM
HOME
TAPE
POWER
AMP IN
CD 1
LLL
AUX
RRR
EXTPHINT
POWER
AMP INPUT
MAIN
OUT
TAP E
OUT
SECTION LOCATIONS
3
TAPE VIDEO CD 2 CD 1 GNDPH AUX
TUNER
IN P UT /D R IV E R
2
PCB
/
AUX
LAM P
4
PCB
TON E
7
PCB
6 5
CONTROL
PCB
PG D ISPLAY
PC
4
BLOCK DIAGRAM
MA6500
CHANNEL
INPUTS
RIGHT
CHANNEL
INPUTS
PORTS
LEFT
DATA
CD1
CD2
TUNER
VIDEO
TAPE
AUX
PHONO
PHONO
AUX
TAPE
VIDEO
TUNER
CD2
CD1
POWER
CONTROL
AUX
TAPE
VIDEO
TUNER
CD2
CD1
SUM
HOME
R IAA
AMP
R IAA
AMP
INPUT
ELECTRO-
MAGNETIC
SWITCHING
INPUT
INPUT
ELECTRO-
ELECTRO-
MAGNETIC
MAGNETIC
SWITCHING
SWITCHING
DATA
PORT
REGISTER
INPUT
SELECTOR
LOGIC
MICRO
CONTROLLER
EXT IR
SENSOR
COMPENSATION
COMPENSATION
IR
SENSOR
LOUDNESS
CONTROL
LOUDNESS
CONTROL
MONO
SWITCHING
MONO
SWITCHING
120VAC
50/60Hz
SUPER TRACKING
VOLUME CONTROL
SUPER TRACKING
VOLUME CONTROL
MAIN
FUSE
20dB
AMP
20dB
AMP
IN RUSH
CURRENT
LIMITER
BALANCE
CONTROL
CONTROLS
BALANCE
CONTROL
POWER
TRANSFORMER
TONE
TONE
AMP
TONE
AMP
RECTIFIERS
AND FILTERS
LAMP CONTROL
TURN-ON
DELAY
LOGIC
LAMP
FUSE
OUTPUT
MUTING
OUTPUT
MUTING
LOGIC
OUTPUT
MUTING
FRONT PANEL
LAMPS
HEAD-
PHONE
AMP
TO PREAMP IN (INT)
PREAMP OUT RIGHT
HEAD-
PHONE
AMP
TO PREAMP IN (INT)
PREAMP OUT LEFT
5.6V
REGULATOR
15V
REGULATOR
-15V
REGULATOR
MATCHING
NETWORK
5.6V
15V
-15V
11.5VAC
HEAD
PHONE
THERMAL
PROTECTION
MAIN
RELAYS
5
MAIN
SUPPLY
6
B+
B-
BLOCK DIAGRAM
LEFT PG
INDICATOR
PG
INDICATOR
DRIVER
POWER
GUARD
DIFF
AMP
CASCODE
VOLTAGE
AMP
POSITIVE
CURRENT
LIMITER
+++
PREDRIVER
DRIVER OUTPUT
SPEAKER
SWITCHING
LEFT
OUTPUT
SPEAKER 1
SPEAKER 2
PRE AMP LEFT
(INT)
PRE AMP RIGHT
(INT)
TO PRE AMP
OUT (INT)
PRE AMP IN
(EXT)
PRE AMP IN
(EXT)
TO PRE AMP
OUT (INT)
POWER AMP
INPUT
SWITCH
POWER AMP
INPUT
SWITCH
RIGHT PG
INDICATOR
TO MICRO CONTROLLOR
PG
DRIVER
ELECTRONIC
ATTENUATOR
ELECTRONIC
ATTENUATOR
POWER
GUARD
CURRENT
SOURCE
DIFF
AMP
DIFF
AMP
CURRENT
SOURCE
DIFF
AMP
CASCODE
VOLTAGE
AMP
CASCODE
VOLTAGE
AMP
CASCODE
VOLTAGE
AMP
DC
BIAS
---
PREDRIVER DRIVER OUTPUT
NEGATIVE
CURRENT
LIMITER
NEGATIVE
CURRENT
LIMITER
---
PREDRIVER DRIVER OUTPUT
DC
BIAS
+++
VOLTAGE
LOG
AMP
NEGATIVE
FEEDBACK
NEGATIVE
FEEDBACK
VOLTAGE
LOG
AMP
OUTPUT DRIVER PREDRIVER
RECTIFIER
RECTIFIER
DC
AMP
DC
AMP
LEFT
METER
RIGHT
METER
TURN ON
DELAY
SPEAKER
SWITCHING
THERMAL
PROTECTION
RIGHT
OUTPUT
SPEAKER 1
SPEAKER 2
POSITIVE
CURRENT
LIMITER
7
8
Loading...