Monoprice 16154 User manual

User’s Manual
P/N 16154
Cables
Computers & Networking
TV Wall Mounts
Audio & Video
Mobile
Camera & Security
Pro Audio & Instruments
Gadgets & Learning
Gaming
Outdoor & Cycling
Stereo Tube Headphone Amp w/ 24bit/96kHz
USB DAC, Bluetooth®, and Preamp Out
www.monoprice.com
Product pictures are for reference only.
Specifications described herein are subject to change without prior notification.
All trademarks are the sole property of their respective companies.
Copyright © 2016 Monoprice, Inc. All rights reserved.

211
REGULATORY COMPLIANCE
Notice for FCC
This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
Modifying the equipment without Monoprice’s authorization may result in the equipment no longer complying
with FCC requirements for Class B digital devices. In that event, your right to use the equipment may be
limited by FCC regulations, and you may be required to correct any interference to radio or television
communications at your own expense.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to
Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the instructions, may cause harmful interference to
radio communications. However, there is no guarantee that interference will not occur in a particular
installation. If this equipment does cause harmful interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to correct the interference by
one or more of the following measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and receiver.
•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
Radio Notice for FCC
Caution
This FCC Part 15 radio device operates on a non-interference basis with other devices operating at this
frequency. Any changes or modification to said product not expressly approved by Monoprice, including the
use of non-approved antennas, could void the user’s authority to operate this device.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
Notice for Industry Canada
This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.
Radio Notice for Industry Canada
Caution
This IC RSS-210 radio device operates on a non-interference basis with other devices operating at this
frequency. Any changes or modification to said product not expressly approved by Monoprice, including the
use of non-approved antennas, could void the user’s authority to operate this device.
This device complies with IC RSS-210. Operation is subject to the following two conditions: (1) this device
may not cause harmful interference, and (2) this device must accept any interference received, including
interference that may cause undesired operation.
CONTENTS
SAFETY WARNINGS and GUIDELINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CUSTOMER SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
PACKAGE CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CONTROLS and CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
CABLE PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Speaker Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
RCA Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Speaker Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Source and Power Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Bluetooth®Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
USB Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
TECHNICAL SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
REGULATORY COMPLIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Notice for FCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Radio Notice for FCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Notice for Industry Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Radio Notice for Industry Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

SAFETY WARNINGS and GUIDELINES
•This device is intended for indoor use only.
•Do not expose this device to water or moisture of any kind. Do not place drinks or other
containers with moisture on or near the device. If moisture does get in or on the device,
immediately unplug it from the power outlet and allow it to fully dry before reapplying power.
•If operating this device in a humid environment, ensure that no condensation occurs.
Condensation could cause a short circuit, which could cause fire or severe electric shock.
•Use only in a well-ventilated area. Do not use in close, confined spaces.
•Do not expose this device to excessively high temperatures. Do not place it in, on, or near heat
sources, such as a fireplace, stove, radiator, etc. Do not leave it in direct sunlight.
•Do not place or install this device in an area where it can be exposed to excessive amounts of
dust, humidity, oil, smoke, or combustible vapors.
•Do not expose this device to excessive vibration.
•Do not subject this device to extreme force, shock, or fluctuations in temperature or humidity.
•Disconnect the unit from the power source when replacing the fuse. Replace the fuse only with
the same type or the type listed in the Specifications section of this manual.
•Unplug this device from the power source if it will go unused for a long period of time.
•Prior to operation, check the unit and power cord for physical damage. Do not use if physical
damage has occurred.
•Before plugging the unit into a power outlet, ensure that the outlet provides the same type and
level of power required by the device, as listed in the Specifications section of this manual.
•This device uses a grounded power cord and requires a ground connection for safe operation.
Ensure that the power source has a proper ground connection. Do not modify the plug or use
a "cheater" plug to bypass the ground connection.
•Do not allow the power cord to be crimped, pinched, stepped on, etc. Ensure that the power
cord does not present a tripping hazard.
•Never unplug the unit by pulling on the power cord. Always grasp the connector head.
•Ensure that power is turned off and disconnected before making any electrical connections,
including audio level connections.
•Unplug the device from the power source before performing any cleaning.
•Clean only using a soft, dry cloth. Do not use chemical cleaners, solvents, or detergents.
For stubborn deposits, moisten the cloth with warm water.
•Keep out of reach of children.
•Keep away from corrosive materials.
•Do not touch the tubes while the amplifier is powered on. After removing power from the
amplifier, wait until the tubes have had a chance to cool down before touching them.
•After receiving the product and before applying power, ensure that the tubes are properly
seated in their sockets. The tubes may come loose during shipping and may need to be
reseated to ensure a good electrical connection.
•Wait at least 10 seconds after powering on the amplifier to allow it to properly warm up before
applying a music signal.
10 3
SPECIFICATION
Frequency Response
Total Harmonic Distortion (@1kHz)
RMS Power Output (100-ohm load @ 1kHz)
USB DAC
Input Sensitivity
Inputs
Signal-to-Noise Ratio
Input Voltages
Fuse Ratings
Tube Type
Bluetooth®Version
Bluetooth Range
Dimensions
Weight
20Hz ~ 30kHz ±2dB
≤ 0.1% @ 100Ω, 1kHz, 300mW
500mW/channel
24bit/96kHz
750mV
CD, USB, Bluetooth®
≥ 88dB
100 ~ 120V 60Hz, 200 ~ 230V 50Hz
F1A /125
2x 6N2
4.0 with aptX® audio codec
Up to 32 feet (10 meters)
7.5" x 5.0" x 9.8" (192 x 126 x 248 mm)
6.61 lbs (3.0 kg)
MAINTENANCE
Note that after years of use, vacuum tubes will not perform as well as when they are new. This
may result in audible distortion at moderate volume levels. If this occurs, you should replace the
vacuum tubes with new tubes of the same type. Since these are not power tubes and no
biasing is required, you can safely replace them yourself.
TECHNICAL SUPPORT
Monoprice is pleased to provide free, live, online technical support to assist you with any questions
you may have about installation, setup, troubleshooting, or product recommendations. If you ever
need assistance with your new product, please come online to talk to one of our friendly and
knowledgeable Tech Support Associates. Technical support is available through the online chat
button on our website www.monoprice.com during regular business hours, 7 days a week.
You can also get assistance through email by sending a message to [e-mail]
The Bluetooth®word mark and logos are registered trademarks of Bluetooth SIG.
CVC®, the aptX®mark, and the aptX logo are trademarks of CSR plc or one of its group companies
and may be registered in one or more jurisdi
Microsoft®and Windows®are registered trademarks of Microsoft Corporation in the United States
and/or other countries.
Apple®, Mac®, and OS X®are trademarks of Apple Inc., registered in the U.S. and other countries.

Source and Power Connections
5. Plug the Bluetooth®antenna into the BT ANT connector on the rear panel. Tighten the
thumbscrew to secure it in place, then position the antenna vertically.
6. Plug one end of a stereo RCA cable (not included) into the CD inputs on the rear panel, taking
care to plug the right channel plug (red) into the red RCA jack and the left channel plug (usually
black or white) into the white RCA jack. Plug the other end into the output jacks on your CD
player or other audio source device.
7. Plug the included USB cable into the USB input on the amplifier, then plug the other end into
a USB port on your computer.
8. Plug the included AC power cord into the AC IN socket on the rear panel. Plug the other
end into a nearby AC power outlet.
Bluetooth Connection
This amplifier features a built-in Bluetooth radio with a range of up to 32 feet (10 meters) for
streaming audio from your mobile device. It can remember up to 8 pairings and will automatically
drop old connections when pairing with a full list. Perform the following steps to connect your
mobile device to the amplifier's Bluetooth radio.
9. Depress the power button on the front panel to turn the amplifier ON.
10. Flip the Source Selection Switch to the BT position.
11. Open the Bluetooth settings on your mobile device and initiate a scan for nearby Bluetooth
devices.
12. Locate and select the MP TUBE entry. If prompted for a passcode, enter four zeroes (0000).
USB Connection
This Stereo Tube Headphone amp is a plug-and play device. Simply plug the supplied USB
cable into the Stereo Tube Headphone Amp and an available USB port on your computer.
Most systems will recognize and switch audio output to this device.
If your system does not automatically switch perform one of the following:
Windows®XP and later:
1. In Control Panel, select Sound.
2. Click the Audio tab, then select the USB audio device e ntr y.
Mac®OS X®10.0 and later
1. Select System Preferences > Sound.
2. Click the Output tab, then select the USB audio codec entr y.
94
INTRODUCTION
Thank you for purchasing this amplifier from Monoprice!
This amplifier utilizes a hybrid design, which combines a tube preamplifier section with a solid
state class AB power amplifier stage. The advantage of listening to a sound system utilizing
tubes is a warmth and depth of sound not possible with systems that are only digital or analog
solid state. There are however some things you should know if you are a first time user of
classic tube amp designs.
1. Transformer hum: The nature of tubes and transformers can produce a natural hum
emanating from the transformer. This hum should not be audible through the speakers, but can
be concerning for first time users. As long as moderate listening levels mask the hum their is
nothing wrong with your Tube Amplifier.
2. Tubes generate heat: Be sure to always keep items clear of this tube amp. When the amp is
used for prolonged periods of time, the tube will generate a considerable amount of heat. Let
the amp cool off before moving it after use. The heated elements of the tube are very fragile and
get damaged easily if shaken after use.
This amp includes a line level stereo RCA input, a Bluetooth®4.0 radio with the aptX®audio
codec for wireless connections with mobile devices, a USB input with a 24bit/96kHz DAC, and
line-level stereo RCA preamp output.
FEATURES
•Tube preamplifier stage
•Built-in Bluetooth 4.0 radio with aptX audio codec
•One line-level stereo RCA input
•RCA line-level output for use with powered speakers
•USB input with a 24bit/96kHz DAC
CUSTOMER SERVICE
The Monoprice Customer Service department is dedicated to ensuring that your ordering,
purchasing, and delivery experience is second to none. If you have any problem with your order,
please give us an opportunity to make it right. You can contact a Monoprice Customer Service
representative through the Live Chat link on our website www.monoprice.com during normal
business hours (Mon-Fri: 5am-7pm PT, Sat-Sun: 9am-6pm PT) or via email at
[e-mail]
PACKAGE CONTENTS
Please take an inventory of the package contents to ensure you have all the items listed below.
If anything is missing or damaged, please contact Monoprice Customer Service for replacement.
- 1x Hybrid class AB integrated amplifier
- 1x Bluetooth antenna
- 2x 6N2 vacuum tubes
- 1x 3-foot USB cable (Type A to Type B)
- 1x AC power cord (IEC 60320 C13 to NEMA 5-15)
- 1x User's manual

8 5
CONTROLS and CONNECTION
Front Panel
1. POWER:Toggles power on/off. When power is on, the LED above the power button is
illuminated.
2. HEADPHONES:1/4" TRS stereo headphone jack
3. CD/BT/USB:Selects which of the three inputs will be used.
6. VOLUME:Adjusts the output volume level.
Rear Panel
5. BT ANT:SMA connector for attaching the included Bluetooth®antenna.
6. CD:Line level left and right RCA jacks for input from a CD player (or other audio source).
7. PRE OUTPUT:Line level stereo RCA preamplifier output.
8. USB: USB input with 24bit/96kHz DAC for connecting a computer.
9. AC IN:Combination power input socket and fuse holder. Plug the included AC power cord
into the IEC 60320 C14 panel connector.
10. VOLTAGE SELECTOR: Use this switch to change the input voltage between 100 ~ 120 VAC,
60Hz and 200 ~ 230 VAC, 50Hz.
1
2 3
4
5
6
Speaker Connections
To CD Player
RL
To Powered Speakers
To Outlet
Computer w/ USB Port
BT
HEADPHONES
POWER
CD
7
8
910
BT
ANT USB
VOLTAGE SELECTOR
PRE OUTPUT AC IN
CD
USB
VOLUME
ON OFF
MIN MAX
CD
BT
ANT USB
VOLTAGE SELECTOR
PRE OUTPUT AC IN
Made in China
P/N 16154
Made in China
P/N 16154

6 7
CABLE PREPARATION
You will need two types of cables for this installation. A USB cable is included with the system.
Important Safety Note! If you plan on running any cables through the walls, through
a connecting floor, or inside an air duct, they should be rated for In-Wall, Riser (between floors),
or Plenum (air duct) use, respectively. Using unrated or improperly rated cables could accelerate
the spread of any fire and could nullify insurance claims.
RCA Cables
You will need a stereo RCA cable to connect the CD player or other source device to the
headphone amplifier’s source inputs. In most cases these will be relatively short connections,
so ordinary RCA cables are sufficient. However, if the distance is longer than about 15-20 feet
(4.5-6 meters), it is recommended to use RCA cables manufactured using shielded RG6 or
RG59 cable. RG59 can connect to distances up to about 131 feet (40 meters), while RG6 can
make reliable connections to distances up to about 328 feet (100 meters).
USB Cables
A USB cable is used to connect to the USB port of a computer to use the computer as an
audio source. A 3-foot USB cable (Type A to Type B) is included.
SETUP
Note: Before making any connections, ensure that all equipment is powered off and unplugged
to prevent the possibility of personal injury or equipment damage due to electrical shock.
Tubes
To prevent damage during shipping, your Compact Stereo Hybrid Tube Amp ships with the tubes
uninstalled. Perform the following steps to install the tubes.
1. Remove one of the 6N2 tubes from its box.
Use gloves when handling the vacuum tubes to prevent oil residue from your fingers
accumulating on the glass, thereby preventing premature tube failure.
2. Position the tube inside one of the tube cages. Align the pins to match the pattern in
the tube socket, with the large gap closest to the rear of the amp. Gently push the tube into
the socket. You may need to gently wiggle or rock the tube to help overcome resistance
from friction. Ensure that the tube is firmly seated in the socket.
3. Using the same procedure, insert the second 6N2 tube into the other tube socket.
Ensure it is fully seated.
4. Position the amplifier in a location in which it can get adequate airflow around the case and
ventilation holes. Do not connect the power cord yet.