McIntosh MC275 Maintenance Manual

600
A/70.7
OUTPUT
RECEPTICAL CONNECTIONS
PIN
1-GROUND,
70.7
V
RETURN,
AND 600 A
C.T.
PINS
1 AND 7-
LEFT
70.7
V
OUTPUT
PINS
2
AND
3 -
LEFT
600 A
OUTPUT
PINS
1 AND 8 -
RIGHT
70.7
V
OUTPUT
PINS
4
AND
5-
RIGHT
600 A
OUTPUT
SINGLE CHANNEL (MONO) OUTPUT NOTE
FOR
SINGLE CHANNEL OUTPUT
PARALLEL
OR
SERIES CONNECT
THE L AND R
OUTPUTS
TO
OBTAIN
DESIRED OUTPUT IMPEDANCE.
* 5%
TOLERANCE RESISTORS
A
FOLLOWING COMPONENTS
ARE
MATCHED
TO 1%:
R11 AND R36 R13 AND R38
R24 AND R27 R49 AND R52
VOLTAGE
AND
RESISTANCE CHART
"This
resistance measured
with
condenser C25A shorted
to
ground.
"This
resistance measured with condenser C24B shorted
to
ground.
High impedance VTVM
is
used
to
measure
the
operating voltages.
Resistance
in
Ohms
Unit
Off
AC
Volts
at
rated output
DC
Volts
No.
Signal
Pin No.
Tube
160K* 1M
3.3K 0
160K*
1M
3.3K
2.1
.47 .44
0 2.1
.47
.44
6.3
100
0
.95 0
100
0
.95
0
1
2 3 4&5 6
7
8 9
12AX7
(VI)
37K*
160K* 18K
0 40K* 2.4M"
18K
0
12
2.1
.96
0
12
0
.96
6.3
240
100 106
0 240 84
106
0
1
2
3
4&5
6 7
8 9
12AU7 (V2 or V5)
12K*
210K 2.7K 0
12K
210K 2.7K 0
152 12
.7
0
152
12
.7
6.3
365 22 40 0 365 22 40 0
1
2
3 4&5 6
7
8 9
12BH7
(V3 or V6)
38**
1M 170K
0 38**
1M 170K
0
112
152 149
0
112 152 149
6.3
205
-57 -57
0 205
-57 -57
0
1
2 3 4&5
6
7 8 9
12AZ7
(V4 or V7)
0 38 260
170K
6
15
0 or 6.3
116
112
149
6.3 or 0
116
0
450 450
-57
0 .6
1
2 3 4 5 6 7
8
KT88/6550 (V8,
V9,
V10.V11)

McIntosh MC275 Specifications

General

Damping factor	20
Amplifier class	-
Frequency range	10 - 70000 Hz
Output impedance	16 Ω
Audio output channels	2.0 channels
Peak power per channel	75 W
Signal-to-Noise Ratio (SNR)	100 dB
Total Harmonic Distortion (THD)	0.50 %
RMS power output per channel (2 Ohm)	150 W
XLR in	Yes
Audio (L/R) in	2
Audio (L/R) out	6
Speakers connectivity type	Binding post
Purpose	Performance/stage
Product color	Black, Silver
Connectivity technology	Wired
Maximum current	3.6 A
AC input voltage	120 V
AC input frequency	50 - 60 Hz
Package weight	34100 g

Weight and Dimensions

Depth	304.8 mm
Width	419.1 mm
Height	209.6 mm
Weight	30500 g