McIntosh MCP 1 Owners Manual

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Introduction WHY A HEAD AMP? It is in the very nature of a moving coil cartridge, the way in which it must be made with the limita­ tions imposed by today's materials, that it requires a head amp. A moving coil cartridge is really an elec­ trical generator. Just like the generators at an elec­ trical generating plant that convert the energy from falling water, the moving coil cartridge must have a source of mechanical energy which it can convert to electrical energy. For the moving coil cartridge the mechanical energy is supplied by the motion of the stylus as it follows the music signal impressed on the record groove walls. The movement of the stylus corresponding to the musical information is very small, being measured in only thousandths of an inch or tens of microns. Such a small mechanical motion converts into a correspondingly small elec­ trical energy. The output of a moving coil cartridge is measured in only millionths of a volt. A typical mov­ ing coil cartridge will deliver only two or three hun­ dred millionths of a volt which is equivalent to an energy output of only a billionth of a watt. The head amp must amplify this energy and increase its volt­ age level to a few thousandths of a volt in order to protect the musical content from loss of information and contamination by interfering electrical fields which surround everything and everyone of us. Such contaminating fields would add noise and hum to the musical signal and decrease its meaning for us. AN ALTERNATIVE DESIGN There is another possible means of increasing the voltage level of the head amp and that is by using an input transformer. While the transformer can in­ crease the voltage output of the moving coil car­ tridge it can not amplify the energy content of the musical signal from the moving coil. Hence as the voltage of the moving coil is increased its cor­ responding current is decreased. The source im­ pedance, the ratio of the moving coil voltage to its current is increased by the square of the voltage gain. Thus a voltage gain of say one hundred times is accompanied by an impedance increase of ten thousand. The higher the impedance of the output circuit the more susceptible it is to interfering hum and noise fields. The head amp can solve this pro­ blem by being designed to have an output im­ pedance of only a few ohms. . . But there is another problem with transformers operating at extremely low voltage levels. The ease with which the magnetic core concentrates lines of magnetic force varies with voltage level at extremely small levels. This variation adds distortion to the music signal at low frequencies. The MCP 1 head amp solves this problem too. The musical definition of the MCP 1 is far superior to input transformers that are many times the weight and size of the MCP 1. For the highest quality music recovery from your recordings it is best to locate the head amp close to the base of the turntable arm. The extremely low energy levels developed by moving coil cartridges must be protected from exposure to loss of quality from long cables to the preamplifier. When the low voltage signals of the cartridge are amplified by the head amp, they can then leave for the preamplifier in robust form, able to survive the passage without loss of content and be uncontaminated by added noise or distortion components. The MCP 1 is powered directly from your 117 volt line. But an ingenious new development from the Mcintosh engineering group completely isolates the MCP 1 from any noise components in the power line. It is imperative that there be no ground loops (multiple grounding paths) on the input and output cables connecting the MCP 1. Each channel of the MCP 1 has independent ground circuits. The input cables from the tonearm must have separate grounds for each channel and these grounds must not connect to the turntable frame ground. The out­ put cables from the MCP 1 should have independent ground paths to the preamplifier. If you would like to, you can test the grounding system using an ohm meter. When testing the MCP 1 without any connec­ tions to other equipment, the ohm meter should measure 200 ohms between the left and right chan­ nel grounds and 100 ohms from each channel ground to the MCP 1 ground terminal. 2 Connect the leads from your turn­ table to the proper impedance for your cartridge on the MCP 1 input. Connect the output of the MCP 1 head amplifier to the moving magnet phono input on the preamplifier. Connect the turntable ground to the MCP 1 ground terminal. Then, connect a ground wire between the MCP 1 ground terminal and the ground terminal on the preamplifier. How To Connect

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Performance Limits And Ratings Performance Limits Performance limits are the maximum deviation from perfection permitted for a Mcintosh instru­ ment. We promise you that when you purchase a new MCP 1 from a Mcintosh franchised dealer, it will be capable of or can be made capable of perfor­ mance at or exceeding these limits or you can return the unit and get your money back. Mcintosh is the only manufacturer that makes this statement. INPUT IMPEDANCES-10, 20, 40 and 90 ohms GAIN -10W - 31 dB, 20W - 26 dB, 400 - 20 dB, 90W - 13 dB FREQUENCY RESPONSE- + 0, -0.5 dB, 20 Hz to 70 kHz TOTAL HARMONIC DISTORTION -Less than .01% SIGNAL TO NOISE RATIO-83 dBA (re: 500µV input at 1 kHz, 10W input, with RIAA equalization) (equivalent to - 149 dBV at input at 1 kHz). PHASE SHIFT-Non inverting CHANNEL SEPARATION -More than 90 dB, 20 Hz to 20 kHz GENERAL INFORMATION SEMICONDUCTOR COMPLEMENT- 22 Bipolar Transistors 2 Integrated Circuits 11 Diodes POWER REQUIREMENT-85-135 V, 50/60 Hz, 2 watts MECHANICAL INFORMATION Size-7 inches wide (17.8 cm) by 33/16 inches high (8.1 cm) by 5 inches deep (12.7 cm) FINISH-Cabinet is rosewood finish on solid macassar ebony. Front panel is black with gold nomenclature. Chassis is black. WEIGHT-3 pounds (1.4 kg) net, 5.5 pounds (2.5 kg) in shipping carton 3