McIntosh C
504 The best Compact Preamplifier
When you
need a reliable, low noise flexible preamplifier in a compact size, you need
the McIntosh C 504.
The values
to look for in a preamplifier are:
Quality
construction and design excellence
Reliability.
Mechanical
strength
Electronic
stability
Convenience
of operation
Versatility
and superipr performance.
The McIntosh
C 504 is a high technology preamplifier in a compact new case size. The
featuter and performance of the C 504 reflect the latest in McIntosh Laboratory
engineering design excellence.
Precision
Tracking Volume Control
The volume
control, manufactured for McIntosh Laboratory, is a step attenuator which has
tracking accuracy within 1 dB throughout its entire range. Such extremely
accurate matching is achieved through electronically controlled trimming of the
resistance material deposited on pairs of miniature printed circuits. Tracking
accuracy and quiet performance as in ordinary volume controls.
True
Loudness Compensation
The C 504
active circuit loudness control is continuously variable, with constant
midrange gain and acts independently of the volume control. The loudness
contour is accurately modeled after the Fletcher Musom family of "Equal
Loudness" curves. Use of this control restores proper listening response
at even the softest listening levels.
FET Analog
Input Switching
All critical
input switching is done electronically using field effect transistor analog
switches. The front panel selector simply switches small amounts of control DC
voltage which turn the FET analog switches on or off. Since the FET analog
switches are located near the input jacks, the length of interconnecting leads
is much shorter. Noise, switching transisnts, and hum pickup are eliminated.
Tri-Frequency
Program Equalizer
Three
separate controls allow the balance and response of musical information to be
adjusted with far more flexibility than with conventional tone controls. The
center frequencies of the controls are 30 Hz, 750 Hz and 10 kHz. Plus and minus
12 dB of ontrol is available. Use of the program equalizer controls does not
affect in the slightest, the low noise, low distortion performance of the
preamplifier. When the equalizer controls are in their center or flat detent
position, their action is neutral and response of the preamplifier is
absolutely flat.
Headphone/Output
Amplifier
The main
output amplifier section of the preamplifier is a push-pull complementary class
AB circuit. Because of the extremely low distortion and power capability of
this circuit it is used for both main and headphone outputs.
Integrated
Circuit Operational Amplifiers
Both the
magnetic phono and the equalizer amplifier stages utilize new high technology
integrated circuit operational amplifiers. Noise factors are incrediably low,
and distortion levels are at or below the limits of present day test equipment.
Specifications
C 504
FREQUENCY
RESPONSE: 20 Hz to 20 kHz +0, -0.5 dB
RATED OUTPUT
LEVELS:
Main Out
: 2.5 V
Headphone
: 750 mV
Tape Out
: 250 mV
DISTORTION: 0.02% (max. at 2.5 V output from 20 Hz to 20
kHz)
INPUT
SENSITIVITY AND GAIN
Input to
Main Out
Phono 1 and
2: 2,2 mV in for 2,5V out (61,1 dB gain
at 1 kHz)
Tuner, Tape
1 and 2, Aux: 250 mV in for 2,5 V out
(20 dB gain at 1 kHz)
Input to
Headphone Out
Phono 1 and
2: 2,2 mV in for 750 mV out (50,7 dB
gain at 1 kHz)
Tuner, Tape
1 and 2, Aux: 250 mV in for 750 mV out
(9,5 dB gain at 1 kHz)
Input to
Tape Out Phono 1 and 2: 2,2 mV in for
250 mV out (41,1 dB gain at 1 kHz)
Tuner, Tape
1 and 2, Aux: 250 mV in for 250 mV out
(0 dB gain at 1 kHz)
SIGNAL TO
NOISE
Phono 1 and
2:
-90 dB IHF
A-weighted, below 10 mV input
-80 dB
unweighted, below 10 mV input
Tuner, Tape
1 and 2, Aux:
- 100 dB IHF
A-weighted, below 250 mV input
-90 dB
unweighted, below 250 mV input
INPUT
IMPEDANCE
Phono
1 and 2 : 47 k Ω and 50 pF
Tuner,
Tape 1 and 2, Aux : 47 k Ω
OUTPUT
IMPEDANCE
Main
Out : less than 100 Ω (to
operate into 5 kW or greater)
Headphone
: 8 Ω
Tape
Out : less than 200 Ω (to
operate into 5 kW or greater)
EQUALIZER
CONTROL RESPONSE
Center
Frequencies: 30, 750, and 10 kHz
Boost and
Cut: ±12 dB
POWER
REQUIREMENT: 120 Volts 50/60 Hz, 25 Watts
SEMI
CONDUCTOR COMPLEMENT
15
Transistors
14 Field
Effect Transistors
11 Silicon
Diodes
11
Integrated Circuits
DIMENSIONS:
Front Panel
(W X H):406 X 92 mm (16 x3-5/8 inches).
Chassis (W x
H x D):375 x 60 x 368 mm (14 3/4 x 2 3/8
x 14 1/2 inches, including connectors). Knob clearance required is 1 1/4 inches
(3.2 cm) in front of mounting panel.
FINISH: Front panel is anodized gold and black with
special gold/teal nomenclature illumination. Chassis is black.
MOUNTING: Exclusive Mcintosh developed professional
PANLOC
WEIGHT: 6,4 kg (14 pounds ) net, 11,3 kg (25 pounds) in shipping carton.