Specifications

INPUT
Both LEFT and RIGHT UNBALANCED and
BALANCED input connectors function in the stereo
mode of operation In the mono mode of operation
only the RIGHT/MONO input in either UNBALANCED
or BALANCED accepts signal In mono the LEFT
channel input connectors are disconnected
Modern technology has made it possible to build
preamps and amplifiers with the high signal to noise
ratio necessary to reproduce the sound quality
present on compact discs The interconnecting
cables can pick up electrical interference from other
equipment or appliances The balanced inputs on the
MC7300 provide a minimum of 40dB more protection
against such noise pick-up
LEFT AND RIGHT OUTPUT TERMINALS
Mclntosh 50 ampere gold plated output terminals
will deliver full output power to speaker wires from
18GA to wire that is 1 /4 of an inch in diameter The
MC7300 has greater than 85 amperes peak output
current to drive speakers whose impedance varies
from 16 ohms to 1 ohm over the speaker's frequency
range Wire can be connected directly to the output
terminal Special lugs or pins that can cause power
loss are not required
AC POWER
The input to the MC7300 is 120 volts 50/60Hz
at up to 13 amps The primary circuit is protected by
a 13 amp fuse The AC auxiliary outlet is not fused
nor switched
TECHNICAL DESCRIPTION
The MC7300 is a stereo power amplifier
designed to operate with loudspeakers having a
nominal impedance of 2, 4 or 8 ohms In mono
operation 1,2,4 8 or 16 ohms
It features a new circuit design that holds
harmonic distortion far below the amplifiers
remarkably low noise floor Only by using special
spectrum analysis measuring techniques is the
distortion measurable at all
DESIGN PHILOSOPHY
The secret to this performance will sound very
simple, but it is more difficult to carry out than it may
seem The principle used in the design of the
MC7300 was to arrange every stage of voltage or
current amplification to be as linear as possible
This linear operation is accomplished by using
several different techniques
1 Each transistor is selected to have nearly
constant current gain (Beta) over the entire
range of currents at which the transistor must
operate
2 The load impedance presented to each
amplification stage is made to be as uniform as
possible for all signal levels
3 The input impedance of stages is increased and
linearized where possible by using emitter
degeneration
4 Resistors and capacitors in the signal path are
carefully selected to have exceedingly low
voltage coefficients (low change of resistance
or reactance with applied voltage) Precision
metal film resistors and low dielectric
absorption film capacitors are used in all critical
circuit locations
5 Output transistors have matched uniform
current gain, high current gain-bandwidth
product, low output capacitance, and large
active-region safe operating area These
characteristics and the automatic tracking bias
system eliminates cross-over distortion The
distortion graphs show clearly that distortion
does not increase at low power output levels
OVER 227 JOULES OF ENERGY STORAGE
Huge main filter capacitors are used to
guarantee an excellent signal to noise ratio and the
energy storage necessary for the wide dynamic range
that "Digital Audio" demands
ILLUMINATED, PEAK RESPONDING OUTPUT
WATTMETERS
The MC7300 is the first high power amplifier to
have REAL OUTPUT WATTMETERS The power
output in WATTS of any amplifier is determined by
multiplying the output voltage (E) by the output cur-
rent (I), El = W Output meters on other amplifiers are
only voltmeters Output current is not considered
Calibration is in watts and is based on the false
MclNTOSH LABORATORY INC., 2 CHAMBERS STREET, BINGHAMTON, NEW YORK 13903
MC7300 Product Preview/Page 5