Technical Description - McIntosh C1000C Owner's Manual

Technical Description

McIntosh Laboratory, the company who introduced the
world's first amplifier that could be called "High Fidelity",
has done it again. The McIntosh Engineering Staff has cre-
ated a Preamplifier without compromise, using the most ad-
vanced McIntosh circuit design concepts.
The C1000 is the third generation of a two chassis de-
sign with fully balanced circuitry that started with the intro-
duction of the C100 in 1997. In the two chassis design, the
power supplies and digital control circuitry are contained in
the Controller Chassis and the second chassis contains the
Preamplifier Circuitry. This prevents the possible introduc-
tion of hum and noise into the audio signal. In the C1000,
an additional refinement has been added to help assure total
channel isolation, dual mono design. There are two indepen-
dent power supplies, one for each channel, and the Pream-
plifier also contains two totally independent preamplifier
circuits. Refer to figures 93, 95 and 96.
Creating an Preamplifier with this level of performance
did not come easily. Many months of design, testing and
measuring were required. Extensive controlled listening
tests, the ultimate form of measuring, were made before the
final design was accepted.
Silent Audio Switching
All of the Audio Signal Switching in the C1000 is per-
formed by 50 Electro-Magnetic devices. This includes the
selection of the desired Audio Input Source for Listening,
for Recording Outputs, External Signal Processing Loop,
Final Audio Output Selection and the Audio Muting Func-
tion. These Electro-Magnetic devices switch silently, with-
out adding noise to the Audio Signal for the lifetime of the
C1000 Preamplifier. The Balanced Input Switching Printed
Circuit Boards for one channel of the C1000 are shown in
figure 92.
Electro-Magnetic Switching is a proven technology that
uses the latest in materials and manufacturing methods.
46
Figure 92
Figure 93 - Top Inside View of the C1000C
Each switch consists of a glass tube filled with an inert oxy-
gen-free atmosphere and sealed with tiny leads protruding
from either end.
These leads extend
into the tube and
overlap one an-
other with a sepa-
ration of a few
thousandths of an
inch. The leads are
made from a fer-
rous material that
is influenced by a
magnetic field.
They are first plated with gold as a base material, then with
rhodium and finally ruthenium. Ruthenium is the best con-
tact material known. Refer to figure 94.
The glass assembly is then placed in the center of a mul-
tilayer coil of copper wire. The entire assembly is molded
together in a tough shock absorbing material. The switch
and coil connectors extend from the bottom in the form of
printed circuit board terminals. When a DC voltage is ap-
plied to the coil, current flows and creates a magnetic field.
The force of the field causes the leads to bend and contact
one another inside the sealed glass tube. The inert gas elimi-
nates corrosion of the contacts and insures a low resistance,
distortion free switch.
Figure 94