Western Electric 91E User manual

END USER GUIDE

To reduce the risk of re or electric shock, do not expose this
apparatus to rain or moisture.
Pour réduire les risques d’incendie ou de choc électrique, ne pas
exposer cet appareil à la pluie ou à l’humidité.
To reduce the risk of electric shock, do not remove exterior panels.
No user-serviceable parts inside. For servicing, refer to qualied
personnel only.
Pour réduire le risque de choc électrique, ne retirez pas les
panneaux extérieurs. Aucune pièce réparable par l’utilisateur à
l’intérieur. Pour l’entretien, s’adresser uniquement à du personnel
qualié.
is symbol is intended to alert the user to the
presence of dangerous voltage within the amplier
enclosure that may be of sucient magnitude to
constitute a risk of electric shock to persons.
Ce symbole est destiné à alerter l’utilisateur de la
présence d’une tension dangereuse à l’intérieur
du boîtier de l’amplicateur qui peut être d’une
amplitude susante pour constituer un risque de
choc électrique pour les personnes.
is symbol is intended to alert the user to the
presence of important operating and maintenance
instructions in the literature accompanying the
amplier product.
Ce symbole est destiné à alerter l’utilisateur de
la présence d’instructions de fonctionnement et
d’entretien importantes dans la documentation
accompagnant le produit amplicateur.
is symbol is intended to alert the user to the
presence of heat sensitive surfaces. Avoid contact
with electron tubes during amplier operation and
for at least thirty (30) minutes after shut down.
Ce symbole est destiné à alerter l’utilisateur de la
présence de surfaces sensibles à la chaleur. Évitez
tout contact avec les tubes électroniques pendant
le fonctionnement de l’amplicateur et pendant au
moins trente (30) minutes après l’arrêt.
is symbol is intended to alert the user to
the presence of Phono Ground option when
connecting phono turntable systems.
Ce symbole est destiné à alerter l’utilisateur de
la présence de l’option Phono Ground lors de la
connexion de systèmes de tourne-disque.

TYPE 91E
INTEGRATED AMPLIFIER
Founded in 1869, we’re an American manufacturer with an enduring relationship
with quality.Today we make stunning listening experiences through innovative audio
equipment and legacy hi- like the 300B vacuum tube.
To ensure optimal amplier performance, please carefully review this End User Guide.
If at any point during operation you are not satised with the quality of this product,
email [email protected], call [phone], or post a letter to the
address below.We believe quality products should come with quality service.
Western Electric
PO Box 10
Rossville, GA 30741
USA
MAKER OF ELECTRON TUBES & HIGH FIDELITY

TYPE 91E
INTEGRATED AMPLIFIER
TABLE OF CONTENTS
INTRODUCTION
Type 91E Integrated Amplier ..................................................................................................... 1
Replica Tubes Disclaimer .............................................................................................................. 1
NOTES FROM THE MANUFACTURER
Patented Steered Current Source Technology (SCS).................................................................... 2
Type 91 - Family History.............................................................................................................. 2
FEATURES & SPECIFICATIONS
In the Box...................................................................................................................................... 4
Features Overview......................................................................................................................... 4
Amplier Data .............................................................................................................................. 5
OPERATION & SAFETY
Top Panel Diagram ....................................................................................................................... 7
Electron Tube Installation & Access ............................................................................................. 8
Front Panel Diagram................................................................................................................... 10
Rear Panel Diagram .................................................................................................................... 11
Basic Hookup Diagram............................................................................................................... 12
Mains Connection....................................................................................................................... 13
Power On & Startup ................................................................................................................... 13
Tube Auto-Bias........................................................................................................................... 13
Post-Startup ................................................................................................................................ 13
Auto-Standby (How to Disable)................................................................................................. 13
Wireless Connectivity (BT) ........................................................................................................ 14
Headphones................................................................................................................................. 14
Output Transformer Block.......................................................................................................... 14
Line Out & Pre-Out................................................................................................................... 15
Break-In Period........................................................................................................................... 15
Amplier Update Procedure........................................................................................................ 15
LCD Screen Functionality .......................................................................................................... 16
Phono Input & Terminations...................................................................................................... 17
Remote Control Operation ......................................................................................................... 17
Level Adjustment........................................................................................................................ 17
Balance Adjustment .................................................................................................................... 18
Remote Control Battery Replacement ........................................................................................ 18
Amplier Safety .......................................................................................................................... 19
Electron Tube Safety ................................................................................................................... 19
WARRANTY & SERVICE
Warranty Policy........................................................................................................................... 21
Product Service Policy & RMA Process...................................................................................... 23
Troubleshooting .......................................................................................................................... 24

TYPE 91E
INTEGRATED AMPLIFIER
1
INTRODUCTION
TYPE 91E INTEGRATED AMPLIFIER
e Western Electric Type 91E is a Class A, single-ended (SE), integrated amplier for high-
delity audio reproduction. Listeners take advantage of more than double the conventional output
power of the Western Electric Type 300B tube. is powerful innovation was made possible by
patented SE circuit topology. e 91E was made for the Western Electric 300B to provide end
users the highest possible performance and quality.
IMPORTANT:
INSTALLATION OF REPLICA 300B TUBES
e 91E was designed for operation with Western Electric manufactured 300B electron tubes.
e application of non-original or replica type 300B tubes may result in weakened performance,
distorted sound, or unexpected behavior, potentially harming both the amplier and the tubes.
Western Electric takes no responsibility for damage caused by the application of replica 300B
electron tubes during operation. If, during an open customer service or repair case, damage caused
by the application of non-original 300B electron tubes is discovered by Western Electric or is
disclosed to Western Electric by the end user, the case will be determined closed and the product
warranty shall be vitiated. Such determinations are nal. See page 21 for full warranty policy.

TYPE 91E
INTEGRATED AMPLIFIER 2
NOTES FROM THE
MANUFACTURER
PATENTED STEERED CURRENT SOURCE TECHNOLOGY
e 91E is the result of years of research and eort by Western Electric engineers to provide
listeners with the absolute nest in SE tube sound.is achievement is made possible by a patented
(U.S.Patent Office10256776) steered current source (SCS) circuit, explained below.
e circuitry embodies an enhanced parallel feed design, wherein the load (primary winding of the
output transformer with the secondary winding connected to the loudspeaker) is AC coupled to
the plate of the 300B tube.DC bias is removed from the transformer and allows for smaller,simpler
transformer designs with no need for a gap in the core. e welcome side eect is the absence of
unsymmetrical magnetic distortions caused by DC current through the transformer. e circuit
topology also strengthens the coupling between tube and load.
Unlike traditional parallel feed topologies, the tube and output transformer are supplied current
by the SCS.Working in Class A mode, and with the transformer AC-coupled, the SCS provides a
constant idle current for the tube’s plate, ensuring a very stable operating point for the tube.
With the reduction of tube current comes decreased AC power dissipation, providing more power
to the load without overstressing the tube. Additionally, the SCS design can achieve an output
power of more than double the conventional 8-10 watts.
TYPE 91 - FAMILY HISTORY
In 1936, under its lm sound subsidiary Electrical
Research Products Incorporated (ERPI), Western
Electric commissioned the 91A amplier for use in
the wall-mounted Type 500A amplier set (cabinet
pictured right). Amplier sets like the 500A combined
with projectors, loudspeakers, and other tube
ampliers to make up “Wide Range” and subsequent
“Mirrophonic” sound systems in the 1930s. Western
Electric manufactured, installed, and maintained these
early sound systems, thus introducing a burgeoning
Hollywood movie industry and moviegoers worldwide
to the magical, yet naturalistic wonder of high-
delity sound reproduction. Even small-to-midsized
hometown theaters, for which the 91A was designed,
could be equipped with lifelike, synchronized sound
for motion pictures.
e 91E continues the legacy of Western Electric
sound. Its proud place in the Type 91 lineage is rooted
in an idea—What is the best possible 300B amplier?

TYPE 91E
INTEGRATED AMPLIFIER
3
Light years beyond the vacuum tube era, the 300B remains the triode of choice
for serious music lovers worldwide. e 91A’s output stage used the 300A (the
300B’s almost identical predecessor) to eortlessly reproduce lm soundtracks in
a large room,but at only 8 watts max.8-10 watts has long been the standard range
for 300B ampliers manufactured over the years. e Western Electric 91E, with its patented steered
current source technology (SCS), unleashes the 300B to perform at more than double the power. e
best possible design allows the 300B to truly sing. We trust listeners will nd just that as Western
Electric sound lls their listening rooms.
e 91E also elevates the listener’s experience with unforgettable industrial design. Liberated from
the 91A’s stock chassis and cabinetry, the 91E is a showpiece that balances rugged retro features, like
nickel-plated handles and an oversized attenuator knob,with stylish glass tube caging and an easy-to-
read LCD screen for an overall modern elegance.
NOTES FROM THE
MANUFACTURER
Experience a powerful new
classic from the maker of
the original 300B

TYPE 91E
INTEGRATED AMPLIFIER 4
IN THE BOX
• 91E Integrated Amplier
• 1x Matched Pair 300B
• 2x ECC81 (pre-installed)
• Remote Control
• Power Cord
• BT Antenna
• Pin Straightener
FEATURES OVERVIEW
Single-Ended (SE) Topology
is product is implemented with single-ended (SE) tube amplier technology.is allows for the
most authentic listening experience possible, compared to push-pull congurations.
Steered Current Source Technology (SCS)
Experience double the traditional output power with advanced, SE circuit design. is new level
of performance is reached by using a fully linear, steered current source controlled exclusively by
the tube’s output voltage (US Patent 10256776). Lush detail in the midrange and masterfully
articulated upper and lower frequencies are revealed. For details see page 2.
Logarithmic Attenuator
A logarithmic attenuator is used to mimic the response of human hearing.e attenuator consists
of only discrete resistors in a ladder conguration that are switched in and out of circuit with relays
to produce a logarithmic attenuation of the output signal.
Interchangeable Output Transformer Block
Common output transformers are large and excessive. e 91E has smaller, interchangeable
transformer block add-ons that allow users to match loudspeaker impedance. e result? Lower
hysteresis, lower distortion, and a lush, black-background soundstage. For instructions on output
transformer block installation and handling, see page 14.
FEATURES &
SPECIFICATIONS
SPANNER TOOL
FOR 300B ACCESS
SPANNER TOOL FOR
OUTPUT TRANSFORMER ACCESS
REMOTE CONTROL
PIN STRAIGHTENER
MATCHED PAIR 300B ELECTRON TUBES
• Spanner Tool (for 300B access)
• Spanner Tool (for transformer access)
• White Safety Gloves
• Warranty Registration Card
• End User Guide

TYPE 91E
INTEGRATED AMPLIFIER
5
FEATURES &
SPECIFICATIONS
LCD Screen
A bright and easy-to-read color display shows the selected input, attenuator level, VU meter, and
system status messages. e display also shows settings which can be adjusted by the included
remote control. For full LCD screen functionality, see page 16.
Remote Control
e included infrared remote control allows for quick adjustment of amplier settings such as input
levels, balance, and LCD screen dimming. For details on remote control operation, see page 17.
Six Audio Inputs
Connect up to six (6) source devices. For a diagram of the amplier’s rear panel see page 11.
Auto-Bias
Microprocessors automatically bias the 300B tube complement each time the amplier is powered
on. No manual adjustment is necessary. For more details on the auto-bias function, see page 13.
Wireless Connectivity
Connect a device to stream audio wirelessly.is is a convenient option for iOS and Android users.
For instructions on how to connect a device, see page 14.
AMPLIFIER DATA
Weight 49lbs / 22.2 kg
Dimensions 18.9 x 15 x 11.1” / 48 x 38 x 28cm
Chassis Machined Aluminum
Colors Nickel, Gold, Black
Operating Voltage 100V / 115V / 230V / 50-60Hz / 150 W
Power Consumption (Operation / Standby) 10W / 0.3W
Operating Temperature (Indoor) 18-32° C / 64-89° F
Operating Altitude 2000m or less
Mains Fuse 2A slow-blow
Electron Tube Complement 1x Matched Pair WE 300B, 2x ECC81
Phono MM Sensitivity (10W / 4Ω) 0.75mV
Phono MC Sensitivity (10W / 4Ω) 70μV
CD Sensitivity (10W / 4Ω) 0.27V