Monoprice Monolith 24460 User manual

Monolith™ by Monoprice
Portable Headphone Amplifier and DAC
with THX® AAA Technology (Dual AKM 4493 DACs & Dual AAA-788 Modules)
P/N 24460
User's Manual

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CONTENTS
SAFETY WARNINGS AND GUIDELINES.............................................................................................................................................................. 3
FEATURES.....................................................................................................................................................................................................................................4
CUSTOMER SERVICE...........................................................................................................................................................................................................4
PACKAGE CONTENTS........................................................................................................................................................................................................5
PRODUCT OVERVIEW........................................................................................................................................................................................................ 5
Top View................................................................................................................................................................................................................................5
Bottom View......................................................................................................................................................................................................................6
Side View...............................................................................................................................................................................................................................6
CHARGING................................................................................................................................................................................................................................... 7
AUDIO INPUT CONNECTIONS....................................................................................................................................................................................8
Analog ......................................................................................................................................................................................................................................8
Digital Optical.................................................................................................................................................................................................................... 9
USB............................................................................................................................................................................................................................................10
INPUT SELECTION ...............................................................................................................................................................................................................10
Automatic ...........................................................................................................................................................................................................................10
Manual....................................................................................................................................................................................................................................10
OPERATION................................................................................................................................................................................................................................ 11
MAIN MENU............................................................................................................................................................................................................................. 12
EQ MENU ....................................................................................................................................................................................................................................12
Shelf EQ................................................................................................................................................................................................................................. 12
PEQ............................................................................................................................................................................................................................................14
DRC ..................................................................................................................................................................................................................................................16
DIRAC SENSAROUND® ...................................................................................................................................................................................................18
SETTINGS ....................................................................................................................................................................................................................................19
SPECIFICATIONS................................................................................................................................................................................................................... 21
TECHNICAL SUPPORT.....................................................................................................................................................................................................22

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SAFETY WARNINGS AND GUIDELINES
Please read this entire manual before using this device, paying extra attention to these
safety warnings and guidelines. Please keep this manual in a safe place for future reference.
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 turn it off and allow it to fully dry before reapplying power.
Do not touch the device or any connected cables with wet hands.
Do not subject the product to extreme force, shock, or fluctuations in temperature
or humidity.
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.
This device contains a Lithium battery. Dispose of this device only in accordance
with local, state, or federal regulations for electronic waste.
Charge the battery before first use and at least once every three months.
Clean using a soft, dry cloth only. Do not use chemical cleaners, solvents, or
detergents. For stubborn deposits, moisten the cloth with warm water.
This device has no user serviceable parts. Do not attempt to open, service, or
modify this device.

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FEATURES
Dual AK4493 32-bit Digital-to-Analog Converter with support for up to 768kHz PCM
and 22.4MHz DSD (Direct Stream Digital™)
Dual THX® AAA-788 amplifier modules with bipolar class-AB output stages, each
providing 220mW of power into 32Ωat less than -140dB THD
Dirac Sensaround® provides a natural soundscape where listeners can enjoy their
favorite media in a way that seems to spread instruments, voices, and objects out
into space, enveloping the listener exactly as the artist intended
Six layer printed circuit board for the highest level of analog and digital signal
integrity
Highest quality NDK low noise, low jitter oscillators
Input options include USB and optical digital audio inputs, as well as an unbalanced
analog stereo audio input
Unbalanced stereo headphone output
Built-in 4000mAh rechargeable battery provides up to 10 hours of audio playtime
Includes USB wall charger for recharging the internal battery.
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 [email protected]

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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 a
replacement.
1x Portable headphone amplifier
1x Protective sock
1x USB wall charger (5 VDC, 2A)
1x Micro USB cable (Type-A to micro Type-B)
1x User's manual
1x Thank you card
PRODUCT OVERVIEW
Top View
1. HEADPHONES: 3.5mm unbalanced headphone output jack.
2. LINE/OPT IN: Combination 3.5mm unbalanced analog stereo input and 3.5mm digital
optical (mini TOSLINK®) input.
3. POWER/VOLUME: With the unit powered off, turn the knob clockwise until it clicks
to turn the unit on. With the unit powered on, turn the knob fully counterclockwise
until it clicks to turn the unit off. With the unit powered on, turn the knob clockwise
or counterclockwise to increase or decrease the volume level.

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Bottom View
4. CHARGE: Micro USB charging port to connect to the included micro USB cable and
USB wall charger.
5. USB: Micro USB digital audio input.
Side View
6. ENTER/INPUT: Momentarily press the button to select options. Press and hold the
button to enter the Input Selection Menu.
7. DECREASE: Momentarily press the button to select the previous menu or to
decrease the value of an edited option.
8. INCREASE: Momentarily press the button to select the next menu or to increase the
value of an edited option.
9. MENU/BACK: Momentarily press the button to enable the Main Menu. Momentarily
press the button to exit.

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CHARGING
1. Plug the included micro USB cable into the CHARGE port on the amplifier, then plug
the other end into the USB port on the included USB wall charger.
2. Plug the USB wall charger into a nearby AC power outlet. A charge indicator will
animate on the display while charging is in progress. When charging is complete,
the screen will go blank.
Notes:
The USB wall charger accepts input voltages from 100 ~ 240 VAC, 50/60 Hz.
Charge the battery before first use and at least once every three months to keep
the battery fresh and capable of holding a full charge.
Charging should be performed at temperatures between +50 ~ +95°F (+10 ~ +35°C).
Attempting to charge at temperatures outside this range could result in failure to
charge properly.

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AUDIO INPUT CONNECTIONS
Analog
Audio input cables are sold separately.
Turn the amplifier and the source device off before making audio connections.
Use a 3.5mm-to-3.5mm stereo audio cable (e.g., PID 9765) to connect the headphone
output of an mp3 player or smartphone to the LINE/OPT IN jack on the amplifier.
Use a 3.5mm-to-RCA stereo audio cable (e.g., PID 9768) to connect the RCA stereo
audio output of an audio source device (e.g., CD player) to the LINE/OPT IN jack on
the amplifier.

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Digital Optical
Audio input cables are sold separately.
Turn the amplifier and the source device off before making audio connections.
Use a TOSLINK®-to-mini-TOSLINK digital optical cable (e.g., PID 1557) to connect the
optical output of an audio source device (e.g., DVD player) to the LINE/OPT IN jack
on the amplifier.
Use a TOSLINK-to-TOSLINK digital optical cable (e.g., PID 1419) and a TOSLINK-to-
mini-TOSLINK adapter (e.g., PID 2671) to connect the optical output of an audio
source device (e.g., DVD player) to the LINE/OPT IN jack on the amplifier.
Multi-channel audio is not supported. The amplifier support LPCM 2-channel input
only.

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USB
Turn the amplifier and the source device off before making audio connections.
Use the included micro USB cable to connect a computer to the USB audio input on
the amplifier.
No drivers are required when connecting to a Mac® OS X® or Windows® computer.
You may need to select USB audio output in your computer's System Preferences or
Control Panel.
Using USB input allows you to use audio playback software of your choice.
Multi-channel audio is not supported. The amplifier support LPCM 2-channel input
only.
INPUT SELECTION
Automatic
By default, the amplifier will automatically select the most recently connected input. This
feature can be disabled in the SETTINGS section of the Main Menu.
Manual
1. Press and hold the MENU/INPUT button on the amplifier to display the Input
Selection Menu on the display.
2. Use the INCREASE and DECREASE buttons to highlight the desired input, then
momentarily press the MENU/INPUT button to select the highlighted entry.

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OPERATION
1. Turn the amplifier off by turning the POWER/VOLUME knob fully counterclockwise
past the click.
2. Connect an audio source device to one of the inputs by following the instructions in
the AUDIO INPUT CONNECTIONS section above.
3. If automatic input selection is disabled, select the desired input by following the
Manual instructions in the INPUT SELECTION section above.
4. Plug a pair of headphones with 3.5mm plug into the HEADPHONES jack on the
amplifier.
5. If your audio source device has a volume control, put the volume at the midpoint.
6. Start audio playback on your audio source device.
7. Turn the POWER/VOLUME knob clockwise to a point just past the click to turn the
amplifier on.
8. Slowly turn the POWER/VOLUME knob clockwise to increase the volume to a
comfortable listening level. If the POWER/VOLUME knob is fully clockwise and the
volume level is still too low, increase the output volume level on your audio source
device. Use the two volumes to find the desired listening level.

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Notes:
You can connect powered speakers or an external amplifier instead of headphones.
If your headphones are equipped with a 1/4" plug, use a 1/4"-to-3.5mm TRS adapter
(e.g., PID 7165).
Use a 3.5mm-to-RCA stereo audio cable (e.g., PID 9768) to connect the
HEADPHONES output of the amplifier to a stereo line input on an external amplifier.
MAIN MENU
Momentarily press the MENU/BACK button to display the Main Menu.
Use the INCREASE and DECREASE buttons to cycle forward or backward through
the list of available menus.
Momentarily press the ENTER/INPUT button to select the displayed menu.
Momentarily press the MENU/BACK button to return to the Main Menu.
The submenus are EQ [1/4], DRC [2/4], DIRAC [3/4], and SETTINGS [4/4].
After about 30 seconds of no button input while any menu or submenu is displayed,
the Display will revert back to the Home Screen.
EQ MENU
The EQ Menu allows you to set the parameters for the Shelf EQ and up to three Parametric
EQs (PEQs).
Shelf EQ
The Shelf EQ is the equivalent of the Bass and Treble controls on a conventional amplifier,
but with more control over the amount of gain and the specific frequencies. The LF GAIN
value applies to all frequencies below the selected frequency, while the HF GAIN value
applies to all frequencies above the selected frequency.

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Perform the following steps to set the Shelf EQ.
1. Momentarily press the MENU/BACK button. The Display will show MAIN MENU [1/4]
EQ.
2. Momentarily press the ENTER/INPUT button. The Display will show EQ MENU [1/4]
SHELF EQ.
3. Momentarily press the ENTER/INPUT button. The Display will show SHELF EQ with a
pointer to the left of the LF GAIN label.
4. Use the INCREASE or DECREASE buttons to increase or decrease the LF GAIN value
from -6.0dB to +6.0dB in 0.5dB increments.
5. Momentarily press the ENTER/INPUT button. The Display will change to show the
pointer to the left of the FREQ label.
6. Use the INCREASE or DECREASE buttons to increase or decrease the FREQ value
from 60Hz to 200Hz in 10Hz increments.
7. Momentarily press the ENTER/INPUT button. The Display will change to show the
pointer to the left of the HF GAIN label.
8. Use the INCREASE or DECREASE buttons to increase or decrease the HF GAIN value
from -6.0dB to +6.0dB in 0.5dB increments.
9. Momentarily press the ENTER/INPUT button. The Display will change to show the
pointer to the left of the FREQ label.
10. Use the INCREASE or DECREASE buttons to increase or decrease the FREQ value
from 5kHz to 12kHz in 1kHz increments.
11. Momentarily press the ENTER/INPUT button. The Display will cycle back to show the
pointer to the left of the LF GAIN label.
12. Momentarily press the MENU/BACK button three times to return to the Home
Screen. Alternatively, wait about 30 seconds and the Display will automatically
return to the Home Screen. The Home Screen will display an EQ ON label, indicating
that EQ is enabled.

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Note: Once a value is changed in any of the above steps, it will take effect whether or not
the ENTER/INPUT button is pressed. There is no Cancel function to abort changes that have
been made.
PEQ
The Portable Headphone Amplifier features three Parametric EQs (PEQs), which you can
use to boost or cut frequencies with more precision than the Shelf EQ offers. Rather than
boosting or cutting all frequencies above or below a particular point, you can boost or cut
a specific range of frequencies within a bell curve.
This gives a greater amount of boost or cut to the frequency at the center of the curve and
a smaller amount to frequencies the further they get from the central frequency. This
allows you to accentuate particular sounds, voices, or instruments in an audio mix. It is also
useful if the speakers, headphones, or even any item within the room has a resonant
frequency that rattles.
With PEQ you can set which frequency is at the apex of the curve, the amount of gain or
attenuation, and the width of the curve.
Perform the following steps to set first of the three available PEQs. The concept is the
same for the other two PEQs.
1. Momentarily press the MENU/BACK button. The Display will show MAIN MENU [1/4]
EQ.
2. Momentarily press the ENTER/INPUT button. The Display will show EQ MENU [1/4]
SHELF EQ.
3. Momentarily press the INCREASE button. The Display will show EQ MENU [2/4]
PEQ 1.
4. Momentarily press the ENTER/INPUT button. The Display will show PEQ 1 with a
pointer to the left of the ENABLE label.
5. If the value for ENABLE is OFF, momentarily press the INCREASE button to change
the value for ENABLE to ON.

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6. Momentarily press the ENTER/INPUT button. The Display will show PEQ 1 with the
pointer to the left of the FREQ label.
7. Use the INCREASE or DECREASE buttons to increase or decrease the FREQ value in
the range 50Hz to 15.0kHz. The FREQ value can be adjusted in 1Hz increments above
50Hz, 10Hz increments above 100Hz, and 0.1kHz increments above 1kHz.
8. Momentarily press the ENTER/INPUT button. The Display will show PEQ 1 with the
pointer to the left of the GAIN label.
9. Use the INCREASE or DECREASE buttons to increase or decrease the GAIN value
from -6.0dB to +6.0dB in 0.5dB increments.
10. Momentarily press the ENTER/INPUT button. The Display will show PEQ 1 with the
pointer to the left of the Qlabel.
11. Use the INCREASE or DECREASE buttons to increase or decrease the Qvalue from
0.5 octaves to 5.0 octaves in 0.1 octave increments.
12. Momentarily press the ENTER/INPUT button. The Display will show PEQ 1 with the
pointer to the left ENABLE label.
13. Momentarily press the MENU/BACK button three times to return to the Home
Screen. Alternatively, wait about 30 seconds and the Display will automatically
return to the Home Screen. The Home Screen will display an EQ ON label, indicating
that EQ is enabled.
Note: Once a value is changed in any of the above steps, it will take effect whether or not
the ENTER/INPUT button is pressed. There is no Cancel function to abort changes that have
been made.

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DRC
DRC is an acronym for Dynamic Range Compensation.
For audio material, Dynamic Range generally refers to the difference between the quietest
and loudest portions of the audio signal. In theory, humans have an audio Dynamic Range
of about 140dB, however in practice, our ears adjust to the prevailing volume level in the
same way our eyes adjust to light levels, making it difficult to see in the dark if exposed to
bright light.
Dynamic Range Compensation is used to reduce the amount of difference between the
quietest and loudest portions of the audio signal. This is generally perceived negatively by
audiophiles and, because Monolith™ by Monoprice products are true audiophile products,
the feature is disabled by default.
The DRC feature built into this Portable Headphone Amplifier starts with an LPF/HPF to
split low and high frequencies (24dB/octave filters at 140Hz). This is followed by two
independent stereo compressors and a mixer to combine the compressed low and high
frequency bands. The DRC operates on the pre-volume control signal, so the DRC threshold
level refers to the level of the incoming signal source.
The Threshold value determines at which point the DRC takes effect.
The Ratio value determines how much compression is added to the signal. The
lowest setting (1.2:1) will have minimal effect, while the highest level (8.0:1) will have
an audible "squashing" effect on your mix.
LF Offset is essentially a separate gain stage for just the LF signal below 140Hz. You
can reduce or enhance the bass using the DRC similar to how studio and concert
sound engineers use multiband compression.
Perform the following steps to configure and use the DRC feature:
1. Momentarily press the MENU/BACK button. The Display will show MAIN MENU [1/4]
EQ.
2. Momentarily press the INCREASE button once. The Display will show MAIN MENU
[2/4] DRC.

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3. Momentarily press the ENTER/INPUT button. The Display will show DRC with a
pointer to the left of the ENABLE label.
4. If the value for ENABLE is OFF, momentarily press the INCREASE button to change
the value for ENABLE to ON.
5. Momentarily press the ENTER/INPUT button. The Display will show DRC with the
pointer to the left of the THRESHOLD label.
6. Use the INCREASE or DECREASE buttons to increase or decrease the THRESHOLD
value from -32dB to -2dB in 1.0dB increments.
7. Momentarily press the ENTER/INPUT button. The Display will show DRC with the
pointer to the left of the RATIO label.
8. Use the INCREASE or DECREASE buttons to increase or decrease the RATIO value
from 1.2:1 to 8.0:1 in 0.1 ratio increments.
9. Momentarily press the ENTER/INPUT button. The Display will show DRC with the
pointer to the left of the LF OFFSET label.
10. Use the INCREASE or DECREASE buttons to adjust the LF OFFSET value from -12dB
to +12dB in 1.0dB increments.
11. Momentarily press the ENTER/INPUT button. The Display will show DRC with a
pointer to the left of the ENABLE label.
12. Momentarily press the MENU/BACK button two times to return to the Home
Screen. Alternatively, wait about 30 seconds and the Display will automatically
return to the Home Screen. The Home Screen will display a DRC ON label, indicating
that DRC is enabled.
Note: Once a value is changed in any of the above steps, it will take effect whether or not
the ENTER/INPUT button is pressed. There is no Cancel function to abort changes that have
been made.

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DIRAC SENSAROUND®
Music is usually mixed with loudspeakers in mind, not headphones. As a result, headphone
listening is often plagued by a distorted soundstage—instruments and voices may seem
incorrectly placed and trapped inside your head, causing an unnatural listening experience
that can result in listener fatigue.
Dirac Sensaround® takes a different approach by using advanced algorithms to reproduce a
sound field similar to that of a professional listening room. Using a pair of ordinary
headphones, you can enjoy your favorite media in a way that seems to spread instruments,
voices, and objects out into space, enveloping you exactly as the artist intended.
Dirac® studies the way sound moves and is reflected by the environment, as well as how
human ears perceive sound in space, in order to innovate beyond the limitations of
conventional surround sound effects. By carefully measuring and modeling a preferred
listening space, Dirac Sensaround® reproduces key acoustic properties associated with
high fidelity stereo/home cinema listening within the headphones themselves.
You will notice that the result sounds vastly different from so-called virtual surround
techniques that color the sound and take the edge away from the recording. Dirac
Sensaround® is not a sound effect to grow tired of, it is a headphone sound field
optimization that you will not want to be without once you have tried it.
Perform the following steps to use Direc Sensaround®.
1. Momentarily press the MENU/BACK button. The Display will show MAIN MENU [1/4]
EQ.
2. Momentarily press the INCREASE button two times. The Display will show MAIN
MENU [3/4] DIRAC.
3. Momentarily press the ENTER/INPUT button. The Display will show Dirac
Sensaround with either ON or OFF to the right of the label.
4. If the value for Dirac Sensaround is OFF and you want to turn it on, momentarily
press the INCREASE button. If the value for Dirac Sensaround is ON and you want to
turn it off, momentarily press the DECREASE button.

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5. Momentarily press the MENU/BACK button two times to return to the Home
Screen. Alternatively, wait about 30 seconds and the Display will automatically
return to the Home Screen. The Home Screen will display a DIRAC label, indicating
that Dirac Sensaround® is enabled.
SETTINGS
The Settings Menu allows you to control various aspects of the Portable Headphone
Amplifier's performance. You can control the following factors.
Auto Input: When Auto Input is enabled, the amplifier will automatically select the
most recently connected input. The possible options are ON (Auto Input enabled) or
OFF (Auto Input disabled).
DAC Filter: DACs require a reconstruction filter to "convert" the discrete samples
into a continuous analog waveform. Usually this is a low-pass filter (LPF) with the
cutoff frequency being 1/2 the sample frequency with a very sharp roll-off
characteristic. Unfortunately, there is no such thing as a perfect reconstruction filter,
so that is why the AKM DAC and other DACs have selectable filter characteristics.
Your headphones and listening requirements vary, so experiment with the different
slopes to find your sound. The possible options are Normal, Slow 1, and Slow 2.
Reset All?: This function allows you to reset all of the settings to the factory default
values. To reset all settings, momentarily press the INCREASE button to change the
displayed value to ON, then momentarily press the ENTER/INPUT button to perform
the reset.
About...: Momentarily press the INCREASE or DECREASE button to display the
product name and software version.
Perform the following steps to adjust the various settings:
1. Momentarily press the MENU/BACK button. The Display will show MAIN MENU [1/4]
EQ.
2. Momentarily press the INCREASE button three times. The Display will show MAIN
MENU [4/4] SETTINGS.

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3. Momentarily press the ENTER/INPUT button. The Display will show SETTINGS [1/4]
AUTO INPUT.
4. If the value for AUTO INPUT is ON and you want to turn it off, momentarily press the
DECREASE button. If it is OFF and you want to turn it on, momentarily press the
INCREASE button.
5. Momentarily press the ENTER/INPUT button. The Display will show MAIN MENU
[2/4] DAC FILTER.
6. Use the INCREASE and DECREASE buttons to set the DAC FILTER value to NORMAL,
SLOW 1, or SLOW 2.
7. Momentarily press the ENTER/INPUT button. The Display will show MAIN MENU
[3/4] RESET ALL?.
8. If you want to reset the Portable Headphone Amplifier's settings to their factory
default values, press the INCREASE button to change the RESET ALL? value to YES,
otherwise leave it set to NO.
9. Momentarily press the ENTER/INPUT button. If you had RESET ALL? set to YES, the
system will reset all settings to their factory default values. The Display will show
MAIN MENU [4/4] ABOUT....
10. If you want to view the product name and software version information,
momentarily press either the INCREASE or DECREASE button.
11. Momentarily press the MENU/BACK button two times to return to the Home
Screen. Alternatively, wait about 30 seconds and the Display will automatically
return to the Home Screen.