McIntosh C-30 preamplifier

The McIntosh C 30 Preamplifier

McIntosh continues research into user desires consistent with high quality music reproduction.

Engineering that is aggressively inquisitive in the search for better ways to bring these user dictated requirements to a technologically superior, innovative and clearly useful result.

Appearance design that has long life, complements the living style, is complimentary to the owner, and is made of materials, whose characteristics permit a like new always appearance.

Easy, to operate; the unique McIntosh designed panels are always easily readable in your choice of home lighting. They are obviously designed by human beings for human beings.

Manufactured of carefully specified and selected component parts that have high quality and long predicted life.

Assembled by highly trained craftspeople who are dedicated to quality, accuracy and perfection.

Thorough verification of the desired capabilities and quality of performance by constant and complete setting throughout the entire manufacturing process.

Here is the latest advanced technology instrument that adds to the already formidable McIntosh reputation.

Five separate tone shaping controls provides musical spectra tone shaping. Each control adjusts two octave band segments to satisfy your personal preference or the demands of the program material. At the detent in the center of the rotation of each control the equalizer circuits are disconnected, completely removed from the operating circuits.

 

Loudness controls in ordinary equipment are usually simple, passive circuits connected to a portion of the rotation range of the volume control. As a consequence, loudness compensation accuracy is dependent on many variables such as speaker efficiency amplifier gain and differences in input level. The C30 loudness control is continuously variable, operates independently of the volume control, and its contour is accurately modelled after the family of "Equal Loudness" curves developed by Drs. Fletcher and Munson.

Ideal volume control tracking accuracy and noise free performance are two of the considerable benefits of the McIntosh Precision Step Attenuator. It is a thirty-two step, 70 dB range control with unheard of tracking accuracy within 1 dB. The extreme accuracy is obtained through special electronically controlled resistance element trimming. The accuracy and quiet operation are maintained because the switch commutator touches only the switch contact pad and not the precision resistor elements.

Headphone loudness is adjusted using the same type of Precision Step Attenuator. The loudness of the program when using headphones is controlled by this front panel control. The control adjusts the output to the headphone jacks only and does not affect the program loudness from the loudspeakers. Then, while wearing the headphones, adjust the headphone level controls to the desired loudness level.

The appearance of a McIntosh speaker eloquently of precision, quality, premier performance and long, trouble-free life. Consider the construction and materials used in the front panel and knobs. Each constituent part is selected for long, wear-resistant life and stable attractive styling. The panel itself is select white flint glass, free from bubbles, flow marks and other faults. It is silk screened on the reverse side with thermal setting epoxy screen inks which practically become a part of the glass. Then it is built into a brightly polished and anodized frame. The knobs used are meticulously machined of solid aluminum then anodized and thermally isolated.

 

Specifications

Frequency Response:  20 - 20,000 Hz +0 -0,5 dB

Max. Voltage Output: 

Main and Tape Output :  10 V from 20 - 20,000 Hz

Line/Headphone Output :  9 V (1,3 V with 8 Ω  headphones) from 20 - 20,000 Hz

Total Harmonic Distortion :  0,007% max. 20 -20,000 Hz at 2,5 V rated output

Sensitivity

Phono :  2 mV for 2,5 V rated output (0,4 mV IHF)

High Level :  200 mV for 2,5 V rated output (40 mV IHF)

Signal-to-Noise Ratio

Phono :  90 dB below 10  mV input (84 dB IHF)

High Level :  100 dB below rated output (86 dB IHF)

Maximum Input Signal

Phono :  100 mV

High Level :  10 V

Input Impedance

Phono :  47 k Ω  and 65 pF capacitance

High Level :  22 k Ω

Voltage Gain

Phono to Tape :  40 dB

Phono to Main :  62 dB

Phono to Headphone/line :  58 dB (51 dB with 8 Ω  headphones)

High Level to Tape :  0 dB

High Level to Main :  22 dB

High Level to Headphone/Line :  28 dB

(11 dB with 8 Ω  headphones)

Equalization Control:  Variable 12 dB boost to 12 dB cut at center frequencies of 30, 150, 500, 1500, 10 k Hz

LF-HF Filter:  Flat or roll-off at 12 dB per octave below 50 Hz and above 7,000 Hz

Semiconductor Complement:  28 Bipolar Transistors; 66 Field Effect Transistors; 15 Integrated Circuits; 91 Diodes; 1 Silicon Controlled Rectifier (SCR)

Power Requirements:  120volts, 50/60 Hz , 25 watts

Weight:  8,2 kg (18 pounds) net