Specifications

REAR PANEL INFORMATION
AUDIO CONNECTORS
The C40 has four groups of audio jacks on the rear
panel, AUDIO INPUTS, RECORD PROCESSOR, LISTEN
PROCESSOR and AUDIO OUTPUTS.
The AUDIO INPUTS are LINE (balanced with XLR
connectors) PHONO, AUX, CD 1, CD 2, TUNER, TAPE
1, TAPE 2 and TAPE 3.
PHONO and AUX are combined on one position of
the selector switches. The user must decide which way
he will use the inputs. A moving magnet phono
cartridge may be plugged into the PHONO input or any
high level source into the AUX. However the insertion
of an RCA plug into the AUX jack switches the phono
preamp off. Only one input may be used at a time.
The RECORD PROCESSOR jacks are for the TO and
FROM processor connecting cables. When the cable
plugs are inserted a switch is activated that puts the
external processor in the RECORD circuit.
The LISTEN PROCESSOR jacks are for the TO and
FROM processor connecting cables. The LISTEN
processor is switched in or out of the circuit by the front
panel PROCESSOR button.. The red LED above the
button indicates that the processor is in the circuit.
The AUDIO OUTPUTS are TAPE 1, TAPE 2, TAPE 3,
MAIN (unbalanced), SWITCHED 1 & 2 and BALANCED
(main, with XLR connectors).
MONITOR AMPLIFIER
The C40 contains a 20 watt per channel MONITOR
AMPLIFIER. It can be used to drive headphones or 8
ohm loudspeakers.
A rear panel input switch selects the input for the
MONITOR AMPLIFIER. The sources are the LISTEN
program line, the RECORD program line, or any high
level EXTERNAL source. When using headphones
plugged into the front panel jacks, the normal position
is LISTEN.
The monitor amplifier LEFT and RIGHT GAIN controls
are located to the left of the INPUT switch. When the
switch is in the LISTEN position, the LEFT and RIGHT
GAIN controls regulate the monitor volume along with
the main front panel VOLUME control. When the INPUT
switch is in the RECORD or EXT position, only the LEFT
and RIGHT GAIN controls regulate the monitor amplifier
volume.
COMPANDOR LEVEL MATCH
The LEVEL MATCH control on the rear panel is used
to adjust the listening level when the expander or
compressor is switched in or out of the circuit.
COMPANDOR SPEED
The SPEED selector on the rear panel is used to
control the rate at which the Compandor System
responds to signals. By switching from FAST to
NORMAL to SLOW, a more gradual rate of change in
expansion or compression occurs. For music with
percussive instruments, such as piano, drums, guitar,
etc., use NORMAL or FAST. In the FAST mode, the
Compandor System follows changes quickly but will
track low frequencies less accurately. Non-percussive
music and voice requires slower speed. At SLOW speed
the low frequency tracking is accurate, but the rate of
response is slower. The NORMAL position is best suited
for most program material.
SPEAKER SWITCHING
A nine pin subminiature "D" connector is provided
for the SCR3 speaker switching accessory.
AC POWER
One unswitched and four switched AC outlets are
provided.
TECHNICAL DESCRIPTION
LOGIC DRIVEN ELECTRO-MAGNETIC SWITCHING
All signal switching in the C40 is done by ELECTRO-
MAGNETIC methods. ELECTRO-MAGNETIC switching
is an old and proven technology that has been blessed
with modern materials and manufacturing methods.
Each switch consists of a glass tube that is filled
with an inert oxygen-free atmosphere and sealed with
tiny leads protruding from either end. These leads
extend into the tube and overlap one another with a
separation of a few thousandths of an inch. The leads
are made from a ferrous material that is influenced by
a magnetic field. They are first plated with gold as a
base material, then with rhodium and ruthenium.
Ruthenium is the best contact material known. The
glass assembly is then placed in the center of a multi-
layer coil of copper wire. The entire assembly is molded
together in a tough shock absorbing plastic. The switch
and coil connectors extend from the bottom in the form
of printed circuit board terminals.
C40 Product Preview Page 5
MClNTOSH LABORATORY INC., 2 CHAMBERS STREET, BlNGHAMTON, NEW YORK 13903