McIntosh 1982 Catalogue

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YOU SHOULD OWN McIntosh BECAUSE TABLE OF CONTENTS Power Amplifiers: MC 2500, MC 2255, MC 2250, MC 2155, MC 2120, MC 502 2-16 PreAmplifiers: C 33, C 29, C 27, C 504 14-24 Tuners: MR 80, MR 78, MR 75 25-37 Tuner-Preamplifier: MX 117 38-45 Receiver: MAC4100 AM/FM Receiver 46-50 Preamplifier- Amplifier: MA6200 51 Loudspeakers: 52-65 The Mclntosh Story 66-67 Equalizers: MQ107, MQ 104 68 FM Guide. . . 69-76 - Mclntosh instruments are design- ed and manufactured for long life. - Mclntosh instruments have always been designed for long life with low maintenance costs and high quali- ty performance. Mclntosh in- struments have been and are the LABORATORY STANDARD for the world. - Until 1949 the performance re- quirements for a Mclntosh had long been an engineering dream. They became a reality with the in- troduction of the first Mclntosh amplifier. Through all these years Mclntosh has produced instru- ments that have exceptionally long life. Clinics held ail over North America have shown that most of the Mclntosh instruments ever manufactured still meet or exceed their original exacting specifica- tions. - Used McIntosh instruments have the highest resale value. Retailers report that customers are constant- ly searching for used Mclntosh in- struments. A Mclntosh does not re- main on the "Used" display long. You'll get more when you trade-in your Mclntosh assuring you of maximum return on your invest- ment, - Mclntosh dedication, not only to improvements, but also to fun- damentals, has justified many patents on basic circuit structures as well as refinements. - Doesn't it make good sense to deal with a company that wants to do as much for you as it possibly can? 1

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Fig. 5 - McIntosh MC 2205 output stage and transformer dred to one. With transistor output stages, a ratio of only about 4 to 1 is required. In tube amplifiers, extremely good balance in the push-pull primary was required if notch distortion was to be avoided. Now, using a single ended push-pull transistor output stage the transformer can be driven in a single ended fashion. One end of the winding Is returned to ground potential. With the transformer at ground, no isolation is required between the input and out- put and therefore a simple auto- transformer can be used. Fig. 5 shows a typical arrange- ment used in our new MC 2205 ampli- fier. The output stages are designed to work optimally into a load impedance of 2.1 ohms and it becomes a simple matter to "tap into" the auto-trans- former for that precise impedance match. Taps for 1 ohm, 2 ohm, 4 ohm and 8 ohm operation are arranged so that the output transistors continue to work into their optimum impedance. The result: full power output at any of these impedances, with no possibility of thermal over-dissipation. Our popular MC 2300 amplifier also uses an auto-transformer and Fig. 6 shows how that amplifier is able to deliver its full rated power (300 watts RMS per channel) into any impedance from 0.5 ohms to 16 ohms, as well as to 25 volt and 70 volt multi- speaker system taps on the transform- er. If we compare these results with those obtained with a similarly rated Fig. 8A - Typical of phase shift in McIntosh auto-transformer at 8 ohms OTL amplifier (Fig. 7) we see that at all but 8 and 16 ohms, continuous operation at theoretical maximum power is impossible because of over- heating and protection circuit limit- ing. Operation at 16 ohms, though possible, is limited to a maximum power output of 150 watts, in this case, while operation into a 70-volt line is impossible because of limita- tions in power supply voltages. What About Phase Shift? Critics opposed to the use of trans- formers in output circuits of audio amplifiers arc quick to point out that "transformers introduce phase shift" at the low and high frequency ex- tremes. As a matter of fact, a properly designed transformer (and we'll get into some of the factors that are in- volved in designing McIntosh output transformers in a moment) can intro- duce about 3 degrees of phase shift at 20 kHz (Fig. 8A), which is certainly insignificant. The typical volume con- trol used on amplifiers (both those that are OTL and those equipped with transformers) introduce more shift than that- about 20 degrees in fact (Fig. 8B). Since an output transformer is driven from an extremely low im- pedance, there is actually more low- frequency phase shift caused by the usual input coupling capacitor at these low frequencies than by the trans- former. So, why haven't more manufactur- ers used output transformers on solid- state amplifiers? Possibly they are not aware of the technology, but more likely they don't want to spend the extra cost. A good transformer is an expensive component. It is heavy, takes up a fair amount of space and contradicts the audiophile's notion that transistorized equipment must be small and lightweight. Be that as it may, the FTC regulations suggest that output transformers are the only logi- cal solution to rating audio amplifiers honestly at 4, 8, 16 or any other impedance required. 1 watt, 8 ohms - Volume Control Clockwise - Volume Control 12 o'clock Fig. 8B - Typical phase shift in a complete Mclntosh amplifier Not Just Any Transformer! At Mclntosh, we wind all our own output auto-transformers. Of course, we could purchase them from any one of a number of transformer companies who do nothing but wind transformers (our power transformers are, in fact, purchased from other suppliers), but we have long since found that trans- formers can't always be made success- fully "according to the book". A great deal of experimentation is required be- fore a new design of a transformer can 10

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THE McINTOSH C 27 STEREO PREAMPLIFIER STATE-OF-THE-ART PERFORMANCE WITH FLEXIBILITY PERFORMANCE LIMITS and RATINGS FREQUENCY RESPONSE: + 0, -0.5 dB 20 Hz to 20,000 Hz. DISTORTION: Will not exceed 0.05% at rated output level, 20 Hz to 20,000 Hz. INPUT SENSITIVITY AND IMPEDANCE: Auxiliary 1 and 2, Tuner, Tape 1 and 2: 250 millivolts at 100,000 ohms. Phono 1 and 2: 2 millivolts at 47,000 ohms and 100 pF. HUM AND NOISE: Auxiliary 1 and 2, Tuner, Tape 1 and 2: IHFA 90 dB; unweighted 85 dB below rated output. Phono 1 and 2 IHFA 85 dB; unweighted 80 dB below 10 millivolts input. OUTPUT LEVEL: Main Output: 2.5 volts with rated input. Maximum output is greater than 10 volts. Tape Output: 0.25 volts with rated input. Maximum output is greater than 10 volts. Center Channel Output: (L + R) 2.5 volts with rated input. SEMICONDUCTOR COMPLEMENT: 18 silicon-planar transistors, 4 silicon diodes, 5 light emitting diodes. AC POWER OUTLETS: 1 unswitched (red), 4 switched (black). POWER REQUIREMENT: 120 volts, 50/60 Hz, 15 watts. FACILITIES AND FEATURES BASS: Separate 11 position rotary switches for each channel. - 17 dB to + 16 dB at 20 Hz. TREBLE: Separate 11 position rotary switches for each channel -20 dB to +20 dB at 20kHz. LOUDNESS: Flat response, or continuously variable loudness equalization as volume level is reduced. BALANCE: Natural balance at center position, attenuation of left or right channel by rotating control. VOLUME: Precision step attenuator for precision tracking at all listening levels. Does not change stereo balance as volume is changed. INPUT: 5 positions-Auxiliary 1 and 2, Tuner, Phono 1 and 2. MODE: 7 positions-Left channel only to both speakers. Right channel only to both speakers, Stereo Reverse, Stereo, Mono (L + R), L + R to Left speaker only, and L + R to Right speaker only. TAPE MONITOR: Two pushbutton switches. Either of two tape recorders may be monitored. TAPE COPY SWITCH: Two pushbutton switches. Either of two tape recorders may be connected to copy from one to the other in either direction. LF FILTER (Rumble Filter): Flat or roll-off 6 dB per octave below 50 Hz, down 12 dB at 20 Hz. HF FILTER (Scratch Filter): Flat or roll-off 6 dB per octave above 5kHz, down 12 dB at 20k Hz. C 504 is a compact state-of-the-art preamplifier. PERFORMANCE LIMITS and RATINGS C 504 is the same as the preamplifier section of the MX 117 found on page 38. MECHANICAL INFORMATION SIZE: Front panel measures 16 inches wide (40.6 cm) by 3 5/8 inches high (9.2 cm). Chassis measures 14 3/4 inches wide (37.5 cm) by 2 3/8 inches high (6.0 cm) by 14 1/2 inches deep (36.8 cm), including con- nectors. 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: Mclntosh developed professional PANLOC. WEIGHT: 14 pounds (6.4 kg) net, 25 pounds (11. kg) in ship- ping carton. 16

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McINTOSH c 29 SOLID STATE STEREO PREAMPLIFIER PERFORMANCE LIMITS and RATINGS FREQUENCY RESPONSE: + 0 -0.5 dB 20 Hz to 20,000 Hz. DISTORTION: .02% maximum at rated output level. 20 Hz to 20,000 Hz. INPUT SENSITIVITY AND IMPEDANCE: Auxiliary, Tuner, Tape 1, Tape 2, 0.25 volts at 250,000 ohms: Phono 1 and Phono 2, 2 millivolts (1,000 Hz) at 47,000 ohms and 65 pF; Microphone, 2.5 millivolts at 500,000 ohms. HUM AND NOISE: Auxiliary, Tuner, Tape 1, Tape 2, IHFA 100 dB; unweighted 90 dB below rated output. Phono 1, Phono 2 IHFA 90 dB; unweighted 80 dB below 10 millivolts input, equivalent to less than 1.0 microvolt at the input terminals. Microphone, 1.5 microvolts at the input terminals. OUTPUT LEVEL: Main Output: 2.5 volts with rated input, less than 100 ohms source impedance, to operate into 10,000 ohms or greater. Tape Output: 0.25 volts with rated input, less than 200 ohms source im- pedance, to operate into 10,000 ohms or greater. Headphone/Line: 0.75 volts into 8 ohm load or 2.5 volts into 600 ohm line. 47 ohms source im- pedance, level controls provided. VOLTAGE AMPLIFICATION: Phono 1, Phono 2 at 1 kHz to Main Output 62 dB, to Tape Output 42 dB, to Headphone/Line Output 72 dB. Auxiliary, Tuner, Tape 1 and Tape 2 to Main Output 20 dB, to Tape Output 0 dB, to Head- phone/Line Output 30 dB. Microphone to Main Output 60 dB, to Tape Output 40 dB, to Head- phone/Line Output 70 dB. SEMICONDUCTOR COMPLEMENT: 9 Integrated Circuits, 2 Transistors, 11 Silicon Diodes, 8 Light Emitting Diodes (LED), 1 Silicon Controlled Rectifier (SCR), 1 Dual Light Depen- dent Resistor Network (LDR). AC POWER OUTLETS: 2 automatic current sensing (green), 4 switched (black) POWER REQUIREMENT: 120 volts, 50/60 Hz, 15 watts. FACILITIES AND FEATURES BASS: Separate 11 position rotary switches for each channel, +20 dB to -20 dB at 20 Hz. TREBLE: Separate 11 position rotary switches for each channel. + 18 dB to - 18 dB at 20,000 Hz. LOUDNESS: Flat response, or continuously variable loudness equalization as volume level is reduced. BALANCE: Natural balance at center position, attenuation of left or right channel by rotating control. VOLUME: Precision step volume control with left to right tracking accuracy within 1 dB through its entire range. INPUT: Six positions-Auxiliary 1 and 2, Tuner, Phono 1 and 2, Microphone. MODE: Seven positions-Left channel only to both speakers. Right channel only to both speakers. Stereo Reverse, Stereo, Mono L + R to left speaker only, and L + R to right speaker only. TAPE MONITOR: Two pushbutton switches. Either of two tape recorders can be monitored by selecting the Tape 1 pushbutton or Tape 2 pushbutton. TAPE COPY SWITCH: Two pushbutton switches. Either of two tape recorders can be connected to copy from tape recorder 1 to tape recorder 2 or vice versa. LF - HF FILTERS: Reduce unwanted high frequency noise (above 7 kHz) and low frequency rumble etc. (below 50 Hz) at 12 dB per octave rate. FRONT PANEL TAPE JACKS: Allows connection to input and output of a tape recorder from the front panel. HEADPHONE JACK: For listening with either low or high impedance dynamic stereo headphones. Power to this jack is supplied by an amplifier in the C 29. SPEAKER SWITCHES: Turn Two sets of speakers on or off when properly interconnected with the accessory Speaker Con- trol Relay. Model SCR-2 (see page 24). MECHANICAL SIZE: Front panel measures 16 inches wide (40.6 cm) by 5-7/16 inches high (13.8 cm). Chassis measures 14-3/4 inches wide (37.5 cm) by 4-13/16 inches high (12.2 cm) by 13 inches deep (33.0 cm), including PANLOC shelf and back panel connectors. Knob clearance required is 1-1/4 inches (3.2 cm) in front of the mounting panel. FINISH: Front panel is anodized gold and black with special gold/teal nomenclature illumination. CHASSIS: Black MOUNTING: Mclntosh developed professional PANLOC. WEIGHT: 21 pounds (9.5 kg) net, 33 pounds (15 kg) in ship- ping carton. 21

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Electronic Laboratories' THE MCINTOSH MX 117 AM/FM TUNER-PREAMPLIFIER MANUFACTURER'S PUBLISHED SPECIFICATIONS: FM Tuner Section: Usable Sensitivity: 1 1 .2 dBf (2.0 uV/300 ohms) 50 dB Quieting Sensitivity: 19.1 dBf, mono; 39.5 dBf, stereo. Signal-to-Noise Ratio: 70 dB minimum, both mono and stereo. Harmonic Distortion: 0.18% mono, 0.38% stereo, maximum. Alternate Channel Selectivity: 78 dB minimum. Image Rejection: 100 dB minimum. Stereo Separation: 45 dB minimum at 1 kHz. AM Tuner Section: Sensitivity: 75 uV (external antenna) Signal-to-Noise Ratio: 45 dB min IHF or 55 dB @ 100% modulation. Adjacent Channel Sensitivity: 30 dB Minimum. Im- age Rejection: 65 dB minimum from 540 kHz to 1600 kHz. Frequency Response: +0, -6 dB, from 20 Hz to 3500 Hz. Preamplifier Section: Frequency Response: +0, -0.5 dB, 20 Hz to 20 kHz. Rated Outputs: Main: 2.5 V; Line: 1.25 V; Headphone: 750 mV; Tape: 250 mV. Distortion: 0.02% max. @ 2.5 V output from 20 Hz to 20 kHz. Input Sensitivity for 2.5 V at Main Out: (Phono) 2.2 mV; (High Level) 250 mV. Signal-to-Noise: (Phono, re: 10 mV in) 90 dB "A" wt'd, 80 dB unwt'd. (High Level, re: 250 mV in): 100 dB wt'd; 90 dB unwt'd. Input Impedance: (Phono 1 & 2): 47 K ohm & 50 pF. High Level: 47 K ohm. Output Impedance: (Main): Less than 100 ohms; (Line): 600 ohms; (Phone): 8 ohms; (Tape): Less than 200 ohms. Equalizer Con- trol Response: ± 1 2 dB at 30 Hz, 750 Hz and 10 kHz. GENERAL SPECIFICATIONS: Dimensions: 16" wide x 5-7/16" high (panel). Chassis: 13" deep. Knob clearance in front of panel: 1 ¼ ". Net Weight: 24 Ibs. Mclntosh Laboratory Inc. remains one of the few companies that continues to offer a high fidelity component which incorporates both FM/AM tuner circuitry and preamplifier-control circuits. It strikes us that for those audio enthusiasts who do want to include radio (and particularly high-fidelity stereo FM radio) as a program source in their audio systems, this combination, on a single chassis, makes a great deal of sense; so much so, in fact, that we have al- ways wondered why other manufacturers have not offered this type of component in greater numbers. After all, it permits the user to choose any power am- plifier he or she requires, allows for the incorporation of two turntables as well as two tape decks, offers the versatility of a separate preamp-control unit while at the same time incorporating a top-perform- ing stereo FM/AM tuner. Front Panel Layout The MX 1 1 7 has the unmistakable Mclntosh front panel look, with its anodized gold and black finish, its gold/teal illuminated nomenclature and its exclu- sive PANLOC mounting system which has become a tradition of Mac equipment. A large, well-illuminated cut-out area of the panel contains the calibrated AM and FM dial scales, and evenly spaced "logging scale" (calibrated linearly in 0.1 increments from 0 to 10), seven small indicator lights (which denote program source selected as well as selection of in- terstation muting during FM listening) and a four- teen-LED solid-state tuning indicator system, con- sisting of ten small dots arranged in a vertical row, a small bar which illuminates to denote stereo signal reception and three bars which tell you whether you are tuned above, below, or precisely "on center" frequency when listening to FM. A conventional, flywheel-coupled tuning knob is positioned to the right of the dial area. All remaining front panel controls are neatly arranged along the lower section of the panel. These include a six-posi- tion, program source selector switch at the lower left (AUX, AM, FM, MUTE {FM}, PH{ono}1 and PH{ono} 2), three tone controls to the right of center (Mclntosh prefers to call them equalizer controls, since they do divide the audio spectrum into three parts, as opposed to simple bass and treble tone controls which usually control wider swaths of fre- quencies), a dual-concentric balance and loudness control and a master volume control at the lower right. Six push-button switches plus a stereo head- phone jack are located to the left of center of the panel. A light-colored button serves as the power on/off switch while the contrasting dark-shaded but- tons handle such functions as TAPE 1 or TAPE 2 monitoring, Tape Copying from either connected tape deck to another, and stereo/mono selection. The loudness control arrangement found on the MX 1 1 7 is different from any that we have previously encountered and we shall have more to say about its action presently. 40 PRODUCT ANALYSIS Fig. 1 -Front panel view of Mclntosh MX 1 1 7 Tuner-Preamplifier

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The continuous improvement of its products is the policy of Mclntosh Laboratory Incorporated, who reserves the right to improve design without notice. Printed in U.S.A. 039383