McIntosh C 504

 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.