miniDSP HA-DSP User manual

miniDSP Ltd, Hong Kong / www.minidsp.com / Features and specifications subject to change without prior notice 1
HA-DSP
DSP-ENABLED PORTABLE HEADPHONE AMPLIFIER
WITH FIR PROCESSING AND CROSS-FEED
User Manual

miniDSP Ltd, Hong Kong / www.minidsp.com / Features and specifications subject to change without prior notice 2
Revision history
Revision
Description
Date
V0.2
Preliminary version
12 June 2017
V0.3
Updated for released plugin
28 June 2017
V1.0
Substantial update for cross-feed plugin
15 November 2018

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CONTENTS
Important Information...................................................................................................................................5
1Product Overview ....................................................................................................................................7
2Quick-start Guide.....................................................................................................................................8
3Charging and Power.................................................................................................................................9
3.1 Fast-charging the HA-DSP...........................................................................................................................9
3.2 Checking battery level ................................................................................................................................9
3.3Turning the amplifier on and off ................................................................................................................9
4Connections...........................................................................................................................................10
4.1 Analog input ............................................................................................................................................ 10
4.2 Digital optical input ................................................................................................................................. 11
4.3 Android.................................................................................................................................................... 12
4.4 iOS (Apple)............................................................................................................................................... 12
4.5 Computer (USB)....................................................................................................................................... 13
4.6 Headphone output .................................................................................................................................. 14
5USB Audio .............................................................................................................................................15
5.1 Android and iOS....................................................................................................................................... 15
5.2 macOS / OS X........................................................................................................................................... 15
5.3 Windows.................................................................................................................................................. 16
5.3.1 Windows default audio device........................................................................................................ 16
5.3.2 ASIO ................................................................................................................................................. 17
5.3.3 miniDSP UAC control panel ............................................................................................................. 17
5.4 DSD playback mode................................................................................................................................. 18
6The miniDSP HA-DSP Controller App (Android) .......................................................................................19
7Installing the Software...........................................................................................................................21
7.1Downloading the software...................................................................................................................... 21
7.2 Installation on Windows.......................................................................................................................... 22
7.3 Installation on Mac.................................................................................................................................. 23

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8Configuring the HA-DSP..........................................................................................................................24
8.1 First-time connection .............................................................................................................................. 24
8.2 Processing overview................................................................................................................................ 25
8.3 Linked mode ............................................................................................................................................ 26
8.4 Input selection......................................................................................................................................... 26
8.5 Input controls .......................................................................................................................................... 27
8.6 Bass and treble controls.......................................................................................................................... 28
8.7 Parametric EQ (PEQ)................................................................................................................................ 29
8.7.1 Overview.......................................................................................................................................... 29
8.7.2 Types of filter................................................................................................................................... 31
8.8 PEQ advanced mode................................................................................................................................ 32
8.8.1 What’s a “biquad?........................................................................................................................... 32
8.8.2 Advanced mode for a single filter ................................................................................................... 32
8.8.3 Parametric EQ file import (REW integration).................................................................................. 33
8.8.4 Biquad design software................................................................................................................... 33
8.9 FIR filtering .............................................................................................................................................. 34
8.9.1 FIR filtering overview....................................................................................................................... 34
8.9.2 FIR filter design software................................................................................................................. 35
8.9.3 Loading filter coefficients in File Mode ........................................................................................... 35
8.9.4 Loading filter coefficients in Manual Mode .................................................................................... 35
8.9.5 Converting PEQ to FIR...................................................................................................................... 36
8.10 Cross-feed processing.............................................................................................................................. 38
8.10.1 Low-pass filter (LPF)......................................................................................................................... 38
8.10.2 FIR filter and Parametric EQ (PEQ) .................................................................................................. 38
8.10.3 Delay................................................................................................................................................ 39
8.10.4 Cross-feed mixing (“Routing”)......................................................................................................... 39
8.10.5 Additional processing ...................................................................................................................... 39
8.11 Avoiding clipping ..................................................................................................................................... 40
8.11.1 A simple example ............................................................................................................................ 41
8.11.2 A more realistic example................................................................................................................. 42
8.11.3 The “no gain” approach................................................................................................................... 43
8.12 Configuration presets.............................................................................................................................. 44
8.12.1 Selecting presets from the front panel............................................................................................ 44
8.12.2 Saving and loading presets.............................................................................................................. 44
8.12.3 Restoring defaults............................................................................................................................ 45
8.12.4 Synchronizing options ..................................................................................................................... 45
9Other Information .................................................................................................................................46
9.1 Specifications........................................................................................................................................... 46
9.2 Firmware upgrade ................................................................................................................................... 47
9.2.1 Windows.......................................................................................................................................... 47
9.2.2 macOS / OS X................................................................................................................................... 49

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IMPORTANT INFORMATION
Please read the following information before use. In case of any questions, please contact miniDSP via the
support portal at minidsp.desk.com.
System Requirements
To configure the miniDSP audio processor, you will require a Windows PC or Apple Mac OS X computer with the
following minimum specification:
Windows
•PC with 1GHz or higher processor clock speed. Intel® Pentium®/Celeron® family, or AMD K6®/AMD
Athlon®/AMD Duron® family, or compatible processor recommended.
•512 megabytes (MB) of RAM or higher
•Keyboard and mouse or compatible pointing device
•USB 2.0 port
•Microsoft• ® Windows® Vista® SP1/ XP pro SP2/Win7/Win8.1/Win10
•Microsoft• ® .NET framework v3.5 or later
•Adobe AIR environment (latest version)
•Adobe Flash player (latest version)
Mac OS X
•Intel-based Mac with 1 GHz or higher processor clock speed
•512 megabytes (MB) of RAM or higher
•Keyboard and mouse or compatible pointing device
•USB 2.0 port
•OS X 10.8 or higher, macOS 10.12 or higher
•Adobe AIR environment (latest version)
•Adobe Flash player (latest version)
Disclaimer/Warning
miniDSP cannot be held responsible for any damage that may result from the improper use of this product or
incorrect configuration of its settings. As with any other product, we recommend that you carefully read this
manual and other technical notes to ensure that you fully understand how to operate this product. The miniDSP
audio processor is a powerful tool, and misuse or misconfiguration, such as incorrectly set gains or excessive
boost, can produce signals that may damage your audio system.
As a general guideline, you should perform the initial configuration of the miniDSP audio processor before
enabling audio through any connected output device or amplification. Doing so will help ensure that the
software is correctly configured.
Finally, note that the miniDSP audio processor is a very flexible device, and many of the questions we receive at
the tech support department are already answered in this user manual and in the online application notes on

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the miniDSP.com website. So please take the time to carefully read this user manual and the online technical
support. Thanks for your understanding!
Warranty Terms
miniDSP Ltd warrants this product to be free from defects in materials and workmanship for a period of one
year from the invoice date. Our warranty does not cover failure of the product due to incorrect connection or
installation, improper or undocumented use, unauthorized servicing, modification or alteration of the unit in any
way, or any usage outside of that recommended in this manual. If in doubt, contact miniDSP prior to use.
FCC Class B Statement
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
•This device may not cause harmful interference.
•This device must accept any interference received, including interference that may cause undesired
operation.
Warning: 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. This
equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance
with the instructions, may cause 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.
Notice: Shielded interface cable must be used in order to comply with emission limits.
Notice: Changes or modification not expressly approved by the party responsible for compliance could void the
user’s authority to operate the equipment.
CE Mark Statement
The HA-DSP has passed the test performed according to European Standard EN 55022 Class B.
A note on this manual
This User Manual is designed for reading in both print and on the computer. If printing the manual, please print
double-sided. The embedded page size is 8 ½” x 11”. Printing on A4 paper will result in a slightly reduced size.

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1PRODUCT OVERVIEW
Thank you for choosing the miniDSP HA-DSP DSP-enabled portable headphone amplifier. The HA-DSP is a:
•DSP processor. The HA-DSP incorporates a powerful set of features. In addition to gain, bass, and treble
controls, it features 10-band parametric EQ and FIR processing on each channel and a powerful and
highly configurable cross-feed capability.
•DAC. The processed digital audio data is fed to a 32-bit ESS Sabre DAC. The USB input also supports
direct DSD (direct stream digital) playback, where DSD audio (DoP) is fed directly to the DAC chip. (DSP
processing is disabled while playing DSD.)
•Headphone amplifier. A Texas Instruments TPA6120 provides up to 100 mW in each channel into 32
ohms with low distortion and a signal-to-noise ratio of 112 dB.
Four DSP processing configurations are stored on-board and can be selected using the button on the front panel
or with the Android control app. The HA-DSP features three inputs –USB, digital optical, and analog –allowing it
to be used with almost any portable music device.
Figure 1 illustrates a typical usage of the HA-DSP.
Figure 1. Typical usage example

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2QUICK-START GUIDE
Quick-start for audio listening:
1. Check that the rear panel switch is set to position 2.
2. Connect an audio source to the analog input. (If connecting to the digital optical input or to the micro-USB
port, see Section 3.)
3. Connect your headphones to the headphone output.
4. Turn on the HA-DSP with the volume knob. Leave the volume knob at a low level at this point.
5. Wait until one of the LEDs on the front panel of the HA-DSP turn on. Start playing audio from your source.
6. Gradually turn up the volume knob.
If connected over USB to an Android device, use the miniDSP HA-DSP Controller app for access to additional
features of the HA-DSP. For full access to all of the advanced features of the HA-DSP, install the HA-DSP-CF
plugin on a Windows or Mac computer.

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3CHARGING AND POWER
3.1 FAST-CHARGING THE HA-DSP
The supplied 2A USB fast charger is the recommended way to charge the HA-DSP. Using this charger ensures
optimum charging. If you need to play audio over USB at the same time as fast charging, play audio through the
HA-DSP’s USB Type A port. Alternatively, connect via a USB hub with at least 2A capacity.
Note: some USB ports supply only limited current. Therefore, while connected to such a device via the Micro-B
port, the HA-DSP will only trickle-charge. If it is in use at the same time to play audio, it may even continue to
drain the battery.
3.2 CHECKING BATTERY LEVEL
1. Turn the amp off (if it is not already)
2. Press and hold the control button.
3. After a second or two, between one and four of the LEDs will light up. One LED means the battery is very
low, while four LEDs means that the battery is fully charged.
4. Turn the amplifier back on if required.
3.3 TURNING THE AMPLIFIER ON AND OFF
To turn the amplifier on, rotate the volume knob clockwise. The DSP will take a few seconds to initialize, after
which one of the LEDs (numbered 1 to 4) corresponding to the selected DSP preset will turn on.
To turn the amplifier off, rotate the volume knob counterclockwise until it clicks and the preset LED turns off.

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4CONNECTIONS
Note: leave the rear panel switch in position 2 regardless of input source.
4.1 ANALOG INPUT
To connect an analog source, plug a 3.5 mm stereo plug into the input jack. The HA-DSP will automatically detect
the analog input and switch to it. USB Audio will be disabled. You can use:
•The supplied 3.5 mm to 3.5 mm cable. This short cable is perfect for connecting to a phone.
•Any other stereo cable with a 3.5mm stereo connector. For example, in some cases, the source may have
RCA jacks. In that case, use an RCA to 3.5 mm adapter cable.
This diagram shows two typical connection examples: