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

TYPE 91E
INTEGRATED AMPLIFIER 6
CD Input Impedance 20kΩ
Phono MM Input Impedance 47kΩ | | 100 pF
SNR MM (10W / 4Ω, input 5mV) 83 dB(A)
SNR MC (10W / 4Ω, input 0.5mV) 73 dB(A)
SNR CD (10W / 4Ω, input 0.5V) 101 dB(A)
CD Frequency Response 15 Hz - 32 kHz (-3 dB)
Phono Frequency Response 30 Hz - 20 kHz (RIAA within +/- 0.5 dB)
Headphone Output Impedance 100Ω
Output Power / 4Ω / THD 10% 2 x 20 watts
Output Power / 4Ω / THD 5% 2 x 16 watts
Output Power / 4Ω / THD 3% 2 x 14 watts
Output Power / 8Ω / THD 10% 2 x 20 watts
Output Power / 8Ω / THD 5% 2 x 16 watts
Output Power / 8Ω / THD 3% 2 x 14 watts
BT* Standard v4.2
BT Codecs BC, MP3, AAC, FastStream, APTX
BT Sample Rate (adaptive) Up to 96kHz / 16-bit
BT frequency response 20 Hz - 20 kHz
BT SNR 96dB
*BT wireless connectivity
FEATURES &
SPECIFICATIONS

TYPE 91E
INTEGRATED AMPLIFIER
7
OPERATION & SAFETY
TOP PANEL
e diagram below shows key features of the top panel. For electron tube installation and access instructions, see
next page. For transformer block installation instructions, see page 14.
300B Electron Tube (Left Channel Access) - See next page for installation instructions.
ECC81 Electron Tube (pre-installed)
Output Transformer Block - See page 14 for handling and instructions.
300B Electron Tube (Right Channel Access)

TYPE 91E
INTEGRATED AMPLIFIER 8
OPERATION & SAFETY
ELECTRON TUBE INSTALLATION
Before powering on the amplier, you must install the included matched pair of 300B electron tubes.
Review the section titled “Electron Tube Safety” on page 19 before proceeding.
Using the included custom spanner tool (Part
No. KS-90001), rotate the metal retaining ring
counterclockwise to loosen it. Remove the
retaining ring by lifting upward.
Carefully remove the protective metal grille,
protective glass cover, and rubber o-ring.
Insert the rst 300B, aligning the two large pins
with the two large holes in the socket. Do not
force the tube into the socket without ensuring
the correct pin orientation.
Notice your 300B electron tubes may have been
pre-assigned to one channel (L or R).
Reinstall the glass cover and metal grille,making
sure the O-ring seats properly. Mount the metal
retaining ring and rotate clockwise until tight.
Repeat steps 1-4 to install the second 300B in
the opposite channel.
ELECTRON TUBE ACCESS
After extended use, it may become necessary to
access the 300Bs for cleaning or replacement. To
access them, rst complete steps 1-2 above.
Next, remove the 300B by gripping the base and
slowly pulling upwards while moving it in a slight,
side-to-side wiggling motion.Work slowly until the
tube is removed.Using excessive force may cause the
tube to suddenly dislodge from the socket, resulting
in damage to the tube and amplier. To reinstall a
300B, follow steps 3-4 above.
DO NOT OPERATE AMPLIFIER WITHOUT GLASS COVER AND METAL GRILLE PROPERLY INSTALLED
CUSTOM SPANNER TOOL
METAL RETAINING RING
METAL GRILLE
GLASS COVER
RUBBER ORING

TYPE 91E
INTEGRATED AMPLIFIER
9
(continued from previous page)
300B Electron Tube Replacement
To ensure optimal performance, each 91E Integrated Amplier is tuned with its included matched pair of
Western Electric 300B electron tubes during nal testing and inspection. If either tube (or both) is replaced,
slight electrical parameter changes may occur, as compared to when the amplier was originally tested. In the
event that 300B replacement is required, we recommend contacting Western Electric to provide an optimized
matched pair.
ECC81 Electron Tube Replacement
With the amplier disconnected from the mains, the ECC81 tubes may be unplugged by holding the glass and
gently pulling up while slightly moving the tube side-to-side. Excessive force should not be used. To reinstall
ECC81’s, align the pins with the socket and slowly push down while slightly moving the tube side-to-side.
Pin Straightening
To prevent breakage of the ECC81 tube pair, a pin-straightener (Part No. PS-7/9) has been
included with your amplier purchase.If tube pins are bent and misaligned while being inserted
into a socket, the tension and strain can cause the glass to break.Tension increases over time as
the tube is heated and cooled. Using a pin straightener before inserting the tube in the socket
helps minimize the chance of breakage.
To use the straightener,slowly and rmly insert the ECC81 with pins aligned and then remove.
Protective Glass Covers
e 91E’s cylindrical tube covers:
1. Prevent skin burns during tube operation
2. Prevent electric shock during tube operation
3. Create a chimney eect to cool the tubes
WARNING
e tubes and tube sockets should never be touched while the amplier is connected to mains power. When
preparing to replace the tube ensure that the mains cable is DISCONNECTED from the amplier. e
amplier should never be powered on without tubes installed. Please also be aware of hot surfaces. Avoid bare
skin contact with electron tube surfaces during operation and for thirty minutes after your amplier is shut o.
Gloves should be worn for the best protection.
OPERATION & SAFETY

TYPE 91E
INTEGRATED AMPLIFIER 10
OPERATION & SAFETY
FRONT PANEL
Front panel features and controls shown below.
Input Selectors
BT Wireless Connectivity- See page 14 for setup
Infrared Receiver
LCD Screen
Power On / Standby
Power On / Standby Indicator
Headphone Output
Attenuator (Volume Control)
Glass Tube Cover - See page 8 for handling
300B Electron Tube

TYPE 91E
INTEGRATED AMPLIFIER
11
REAR PANEL
e rear panel features ve RCA inputs and a phono load option, as shown below. Capacitive and
resistive phono termination plugs can be purchased from westernelectric.com in a variety of values.For
more information on how phono termination plugs are used, see page 17.
Phono Ground
Phono Toggle Switch - Moving Coil / Moving Magnet
Control Ports (3.5mm) - For interfacing with other audio
equipment. When amplier is on, control ports output +5V.
BT Antenna - For wireless connectivity - See page 14 for setup
USB - Service Access Only
Ethernet - Service Access Only
Mains Switch / Power
OPERATION & SAFETY

TYPE 91E
INTEGRATED AMPLIFIER 12
USB - Service Access Only
Ethernet - Service Access Only
Mains Switch / Power
OPERATION & SAFETY
BASIC HOOKUP
e diagram below shows a common conguration with source device and loudspeakers. To learn
what happens during amplier power on and startup, see next page.

TYPE 91E
INTEGRATED AMPLIFIER
13
OPERATION & SAFETY
Mains Connection
When plugging in the mains power cable, ensure the mains switch is in the o or “O” position.
Keep the mains switch in the o position while connecting or disconnecting external equipment
to the amplier. In order to power on the amplier, the mains cable must be plugged in with the
mains switch on or in the “I” position. With the mains switch on, the LED status light will glow
blue while the amplier is in standby mode.
Power On and Startup
With 300B electron tubes properly installed (see page 8 for electron tube installation instructions) and
the rear panel mains switch in the on or “I” position, press the front panel power button. As the
amplier powers on, the LED status light will ash blue. After approximately ten (10) seconds an
image of the Western Electric mascot will appear shortly after power up. e amplier then goes
through a warm-up period and auto-bias period each lasting thirty (30) seconds.
Tube Auto-Bias
During this 30 second period, the 300B tube anode voltage is turned on and a processor measures
anode voltage and sets the grid bias operating point. is is repeated once every second for thirty
(30) seconds to ensure a stable operating point. Because the bias value of a 300B can change over
its lifetime, the 91E performs this automatic bias process each time the amplier is powered on.
For tube bias troubleshooting, go to page 24.
Post-Startup
Once the amplier is completely powered up and out of standby mode it is ready for use. Your
source device and loudspeaker hookup cables can be connected to the rear panel, accordingly. For
a detailed diagram of the rear panel, refer to page 11. Select the correct input and enjoy the music.
Attenuation can be adjusted in 0.5dB increments by rotating the volume knob or via remote control.
Auto-Standby
By default, the 91E has auto-standby enabled. Auto-standby enables standby mode after no audio
signal has been detected for twenty (20) minutes. e purpose of auto-standby is to save power
when the amplier is not in use. If auto-standby is triggered, you must press the power button to
power on and resume normal operation.
To disable auto-standby, rst make sure the rear panel mains
switch is in the o position then press and hold the power
button. With the power button still depressed, switch the
mains switch to the on position. e LED status light will
ash on for 100ms and o for 900ms (short ash), indicating
auto-standby is disabled.
To re-enable auto-standby, repeat the same procedure described above.is time, the LED status
light will ash on for 500ms and o for 500ms (long ash), indicating that auto-standby is re-
enabled. After either disabling or re-enabling auto-standby, the power button can be pressed to
power on the amplier.
DISABLE
AUTO-STANDBY

TYPE 91E
INTEGRATED AMPLIFIER 14
Wireless Connectivity
Wireless connectivity is a convenient option for many listeners using an iOS device, Android
device, or computer for digital streaming.Before connecting a device,you must attach the included
BT antenna to the RP-SMA port on the back of the amplier. See rear panel diagram on page 11.
After attaching the BT antenna, you may proceed with connecting a wireless device. Press the BT
input button on the front panel of the amplier. A red antenna logo will appear on the LCD screen,
meaning no devices are paired with the amplier. On the device to be paired, search for available
BT connections nearby. Select “WE 91-E BT” to pair. Once paired, the antenna logo will change
from red to white, indicating the amplier is ready to stream audio wirelessly. When a dierent
input is selected, the amplier will automatically disconnect from the paired device.
Headphones
A ¼” (6.3mm) jack is located on the front panel for use with headphones with 100-ohm output
impedance.e amplier automatically adjusts output level for low-resistance and high-resistance
headphones.
Output Transformer Block
e 91E has a pre-installed 8-ohm output transformer block optimized for most 4 ohm to 8-ohm
loudspeakers. You may swap the default 8-ohm transformer block with 4-ohm, 16-ohm, and 24-
ohm options to further optimize your loudspeaker pairing. Visit westernelectric.com to purchase.
Before switching your output transformer
block option, ensure that the amplier mains
switch is in the o position and the unit is
unplugged from its power source. You may
then use the included spanner tool (M2.8
or #10) to remove the four bolts holding the
transformer block housing in place. Carefully
remove the engraved lid to reveal the output
transformer circuit board inside. Set lid aside.
Grip the sides of the transformer block
housing and slowly pull up to detach it from
the top panel of amplier.
Next, remove the six (6) 2mm hex screws
holding the output transformer circuit board
in place. You may now swap the output
transformer circuit board with your desired
option (e.g. 4-ohm). Replace the six (6) 2mm
hex screws.
Re-attach the transformer block by pushing
the block down into the connectors (female)
on the top panel of the amplier. Replace lid
and four bolts.
OPERATION & SAFETY

TYPE 91E
INTEGRATED AMPLIFIER
15
Line Out & Pre-Out
In addition to standard binding posts for loudspeaker output, there are output options labeled
“Line Out” and “Pre-Out.” e line out option is used to pass a xed signal from the amplier to
an external device (e.g., tape recorder). e line out signal is not inuenced by attenuator output
(volume control). Output remains enabled when headphones are connected.
e pre-out option is used to pass a variable signal to an external device. e pre out signal follows
attenuator output (volume control) and is commonly used for connecting subwoofers or a second
power amplier, also known as bi-amping. Output is disabled when headphones are connected.
Break-In Period
e sound and performance of power tubes can change over time.Components within the amplier
may also require time to fully stabilize.Most of the change occurs in the rst 100 hours of listening.
Please allow for a 100-hour break-in period for the tubes and amplier components to stabilize
and truly perform. In some cases, the Western Electric 300B requires up to 500 hours to properly
break-in.is is also known as “burn-in.”
Amplier Update Procedure
e 91E has the capability to execute software updates over the Internet. To get started, you must
connect your unit to the Internet with an ethernet cable.
To check for an update the amplier must be put into update mode. To do this ensure the AC
mains switch is powered o then while holding BT and phono buttons turn on the AC mains
switch. e amplier will then check for a software update and if a newer version exists it will
perform the update. During the update process, the following screen possibilities may appear:
OPERATION & SAFETY