McIntosh MCP-1 Owners manual

Your MCP 1 Head Amplifier is designe d to oper­ate to its performance limits for many years. If
you have any questions , please contact:

CUSTOMER SERVICE

Mcintosh Laboratory Inc.

2 Chambers Stree t

Binghamton, New York 13903-2699
Phone: [phone]

Take Advantag e of 3 years of
Contract Service...

Fill in the Applicatio n NOW.

CONTENT S

SERVICE CONTRAC T INFORMATION 1

INTRODUCTION 2

HOW TO CONNECT 2,3

PERFORMANCE LIMITS 3

HOW TO DESIGN A HEAD AMP 4

MCP-1 SCHEMATIC DIAGRAM 5

McINTOSH THREE YEAR SERVICE CONTRACT

An application for A THREE YEAR SERVICE CONTRAC T is included with this manual .

The terms of the contract are:

1. Mcintosh will provid e all parts, materials and labor neede d
to return the measured performance of the instrument to
the original performance limits. The SERVICE CONTRAC T

does not cover an y shipping cost s to and from the authoriz ­ed service agenc y or the factory.

2. Any Mcintosh authorized service agency will repair
Mcintosh instruments at normal service rates. To receive
service under the terms of the SERVICE CONTRACT, the

SERVICE CONTRACT CERTIFICATE must be presented
when the instrument is taken to the service agency .

3. Always have servic e done by a Mcintos h authorized service

agency. If the instrument is modified or damaged as a
result of unauthorize d repair, the SERVICE CONTRAC T will
be cancelled. Damage by improper use or mishandling is
not covered by the SERVICE CONTRACT .

4. The SERVICE CONTRACT is issued to you as the original
purchaser. To protec t you from misrepresentation , this con-

tract cannot be transferred to a second owner.

5. To receive the SERVICE CONTRACT, your purchase must
be made from a Mcintosh franchised dealer.

6. Your completel y filled in applicatio n for the SERVIC E CON­TRACT must be postmarke d within 30 days of the date of
purchase of the instrument.

7. To receive the SERVICE CONTRACT , all information o n the

application must be filled in. The SERVIC E CONTRAC T will
be issued when the completely filled in application is
received by Mcintosh Laboratory Incorporate d in Bingham­ton. New York.

8. Units in operation outside the United States and Canada
are not covered by the Mcintosh Factory Service Contract ,
irrespective of the place of purchase. Nor are units ac­quired outside the U.S.A. and Canada, the purchasers of
which should consul t with their dealer to ascertai n what, if
any, service contrac t or warranty may be availabl e locally.

Copyright 1983 © by Mcintosh Laboratory Inc.

1

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 elec­trical 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 elec­trical energy. The output of a moving coil cartridge is
measured in only millionths of a volt. A typical mov­ing coil cartridge will deliver only two or three hun­dred 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 volt­age 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

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.

How To Connect

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 in­crease the voltage output of the moving coil car­tridge 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 pro­blem by being designed to have an output im­pedance 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.

Connect the leads from your turn­table 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.

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 out­put 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 connec­tions to other equipment, the ohm meter should
measure 200 ohms between the left and right chan­nel grounds and 100 ohms from each channel

ground to the MCP 1 ground terminal.

2