Mark Levinson 326S User manual

No326S
PREAMPLIFIER

The Nº326S Preamplifier is a direct descendant of
the critically acclaimed Nº32 Reference Preamplifier.
The Nº326S features audio circuits, controls, archi-
tecture, and a phono input option based on the
Nº32. In fact, some audio circuits, such as the
proprietary discrete volume attenuators, are identi-
cal 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 interfer-
ence. 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 tech-
nologies. 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 trans-
formers. 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 regula-
tion 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 sepa-
ration and exceptional sonic imaging. Both audio
channels use independent power supplies, commu-
nication circuits, and audio circuits. In addition,
each channel's audio circuits are located in a sepa-
rate 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 associat-
ed 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 atten-
uator 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.
N
o
326S
PREAMPLIFIER
Nº326S optional phono modules.

Unlike other stereo preamplifiers, the Nº326S is
designed to integrate with multi-channel surround
sound processors - minus the drawback of compet-
ing master volume level controls. A unique
surround sound processor mode allows the Nº326S
to set its master volume level control to unity gain,
passing complete control to the surround sound
processor. With no interference from the Nº326S,
the surround sound processor can maintain the rela-
tive volume level of all channels without distorting
its carefully calibrated input and output levels.
A modest connector complement includes three
balanced (XLR) and four single-ended (RCA) input
connectors. Single-ended input signals are converted
to balanced signals upon entering the chassis, and
processed as balanced signals thereafter. During this
conversion process, meticulously balanced circuits
preserve all input signal information, passing it to
the power amplifier without the limitations of more
asymmetrical single-ended designs.
The phono option, based on the No 32 design,
offers two channels of world-class phono preamp
that integrates seamlessly into the No 326S. Upon
installation, the No 326S automatically recognizes
the phono modules and assigns them to input 7.
The modules are highly configurable and customiz-
able. They work in conjunction with No 326S
software to offer accurate set-up and calibration for
virtually any LP source.
The rear panel includes separate main and record
output connectors, as well as two Link communica-
tion ports that make it possible for the Nº326S to be
included in Mark Levinson Link systems.
A large front panel “select” knob provides quick
selection of the desired input. When an input is
selected, just press and hold the front panel or
remote control setup button to open the correspon-
ding Set Inputs menu, which can be used to select a
custom name, optimize gain levels, set a master
volume level offset, or assign record output connec-
tors to individual inputs.
Following in the footsteps of the Nº32, the Nº326S
exceeds all reasonable expectations for a stereo
preamplifier. Its flexible design, including seven
configurable inputs, separate main and record
outputs, and full surround sound processor integra-
tion, allow it to accommodate a wide range of
demands. All this, plus the addition of an Arlon 25
main circuit board, create a preamp that is equally at
home in a dedicated two-channel audiophile listen-
ing room as it is in extensive theater installations.
Highlights
• Arlon 25 main circuit board
• 7 configurable inputs
• Separate main and record outputs
• 3 balanced (XLR) inputs
• 4 single-ended (RCA) inputs
• Complete surround sound processor integration
• Advanced dual-mono design
• Maximum channel isolation
• Independent power supplies for audio circuit
and control sections, each with their own low-
noise toroidal transformer
• Effective noise suppression and isolation tech-
nologies
• AC power filtering
• Two active voltage regulation stages
• Faraday shield to separate AC power from low-
voltage secondaries
• Independent audio circuits, communication
circuits, and power supplies for each channel
• Two separate proprietary discrete volume atten-
uator modules
• Deactivation of unused inputs to eliminate
ground loop noise
• Balanced conversion for single-ended input
signals
• Intuitive Set Inputs menu
• Large front panel display
• Two Mark Levinson Link communication ports
• RS-232 communication port
• Trigger output connector
• IR input connector
• Phono input option
Nº326S shown with the
steel shield box removed.

3 Oak Park, Bedford, MA 01730-1413 USA
Tel: [phone] | Fax: [phone]
www.marklevinson.com
Mark Levinson®is aregistered trademark of
Harman International Industries, Incorporated.
Not responsible for typographic errors.
Part # 072-16467
Specifications are subject to change without notice.
Nº326SPreamplifier
Gain: 0, 6, 12, or 18dB in the line input stage
Volume control range: 80.0dB (maximum)
Gain resolution: 0.1dB steps above 23.0 in display (–57dB)
1.0dB steps below 23.0 in display (–57dB)
Input overload:
when gain is set to +18dB: 1.6V on XLR, 0.8V on RCA
when gain is set to +12dB: 3.3V on XLR, 1.6V on RCA
when gain is set to +6dB: 6.6V on XLR, 3.3V on RCA
when gain is set to 0dB: 13.2V on XLR, 6.6V on RCA
Input impedance: 100kΩ
Output impedance: less than 50Ω
THD + N less than 0.001%
Crosstalk: <90dB (any input to any output, input terminated)
Residual noise: <-94dBV (20Hz to 20kHz, input terminated)
Frequency response: 10Hz-40kHz: ±0.2dB
Power consumption: 50 watts maximum
Mains voltage: 100V, 120V, 220V, or 230V, factory set for destination country
Mains frequency: 50 or 60Hz, factory set for destination country
Preamplifier inputs*: (3) pairs balanced on XLR
(4) pairs single-ended on RCA
Preamplifier outputs: (1) pair balanced main output on XLR
(1) pair single-ended main output on RCA
(2) pairs record outputs on RCA
Other connectors: (2) link communication (one 8-pin modular RJ-45 connector for “slave-in”
and one 8-pin modular RJ-45 connector for “slave-out”)
(1) phono ground on binding post
(1) IR input on 3.5mm miniature phone connector
(1) trigger programmable output on 3.5mm miniature phone connector
(12V level or 5V pulse)
(1) RS-232 on 6-pin RJ-11 modular connector
(1) AC input on IEC-standard AC mains receptacle
Overall dimensions: width: 17.75" (45.1cm)
height: 2.915" (7.4cm)
depth: 14.05" (35.7cm)
Shipping weight: 30lb (14kg)
Remote control: Hand-held infrared remote control unit
Requires 2 AAA batteries (Alkaline batteries recommended).
*Nº326S phono input option is available at additional charge.
When installed, input 7 becomes the phono input.
Unless otherwise noted, specifications reflect nominal values over 20Hz to 20kHz measured
bandwidth on balanced XLR connections.