Mark Levinson 326S User Manual

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The Nº326S Preamplifier is a direct descendant of
the critically acclaimed Nº32 Reference Preamplifier.
The Nº326S features audio circuits, controls, archi­tecture, and a phono input option based on the
Nº32. In fact, some audio circuits, such as the
proprietary discrete volume attenuators, are identi­cal to those found in the Nº32. These qualities are
also shared by our No 320S. But in addition, the No
326S features a main circuit board comprised of
Arlon 25. This remarkable material allows for a
more open, detailed sonic presentation and an
engaging depth of image that audiophiles worldwide
have come to revere.

The single-chassis design of the Nº326S achieves
similar separation of audio circuit, control, and
power supply sections as the dual-chassis Nº32.
Inside the Nº326S, these sections are separated by
physical layout as well as a steel shield box that
protects against electrostatic and magnetic interfer­ence. Filtered AC power is routed outside audio
circuit sections, providing audio circuits with the
quiet, shielded environment essential for superior
sound.

Many high-performance audio components rely on
clean, noise-free AC power to deliver maximum
performance. Unfortunately, most AC power does
not meet these standards. Common household
appliances such as refrigerators, televisions, and
computers often contaminate AC power lines with
line noise, spikes, and other irregularities that make

it difficult for high-performance audio circuits to
reach their full potential.

To compensate for this, the Nº326S offers a series of
highly effective noise suppression and isolation tech­nologies. AC power is filtered for noise as soon as it
enters the chassis. The audio section and control
section have completely independent power
supplies, each with their own low-noise toroid trans­formers. The audio power transformer features a
Faraday shield between the AC line and the low
voltage secondaries for improved isolation. The
Nº326S employs two stages of active voltage regula­tion for the audio sections. A high-power stage
absorbs line voltage and temperature variations,
while a second high-performance stage provides
local, high-speed, low-noise power for the audio
section.

Featuring an advanced dual-mono design, the
Nº326S is endowed with remarkable channel sepa­ration and exceptional sonic imaging. Both audio
channels use independent power supplies, commu­nication circuits, and audio circuits. In addition,
each channel's audio circuits are located in a sepa­rate area of the chassis. This innovative design
isolates each channel from the other, allowing the
Nº326S to produce vividly rich, three-dimensional
sonic images with stunning precision.

For even greater isolation, the Nº326S deactivates
unused inputs to prevent interference from associat­ed components. When an input is deactivated, the
Nº326S disconnects the input signal and ground
connection, eliminating ground loop noise between
the Nº326S and the associated component. As a
result, input signals pass through the Nº326S with
exceptional freedom from interference due to other
components.

Two Mark Levinson-designed discrete volume atten­uator modules control master volume level with
unparalleled accuracy and sonic neutrality.
Constructed with Arlon 25N circuit boards with
local power supply regulation and bypass capacitors,
these modules generate optimal power and isolation
for even the most sensitive adjustments. Precision
surface-mounted resistors accommodate
adjustments in 1.0dB increments up to 23.0dB and

0.1dB increments above 23.0dB.

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Nº326S optional phono modules.