ALFAtron ALF-DSP88-U User manual

www.alfatronelectronics.com
ALFATRON ELECTRONICS GmbH
Germany
ALF-DSP88-U
8x8 Digital Sound Processor
All Rights Reserved
Version: ALF-DSP88-U V1.1 22022022

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Table of Contents
1. Hardware .......................................................................................... 5
1.1 Safety Instructions....................................................................................................................................5
1.2 Audio Wiring Reference ...........................................................................................................................6
1.3 Specifications ...........................................................................................................................................7
1.4 Mechanical ...............................................................................................................................................8
1.5 Front Panel ...............................................................................................................................................8
1.6 Rear Panel................................................................................................................................................9
2. Technology Overview ....................................................................... 9
2.1 Introduction to DSP Technology ..............................................................................................................9
2.2 Audio Input Section ................................................................................................................................10
2.3 Audio Output Section ...........................................................................................................................111
2.4 Floating Point DSP...............................................................................................................................111
2.5 Audio Flow............................................................................................................................................133
2.6 Typical System Application ..................................................................................................................144
3. Software........................................................................................ 155
3.1 Software Installation.............................................................................................................................155
3.2 Using the Software.................................................................................................................................16
3.3 Audio Module Parameters......................................................................................................................16
3.3.1 Input Source ..................................................................................................................................177
3.3.2 Expander .......................................................................................................................................177
3.3.3 Compressor & Limiter......................................................................................................................19
3.3.4 Automatic Gain Control ...................................................................................................................20
3.3.5 Equalizers........................................................................................................................................21
3.3.6 Feedback Suppressor .....................................................................................................................22
3.3.7 AutoMixer.........................................................................................................................................24
3.3.8 Acoustic Echo Cancelation..............................................................................................................25
3.3.9 Noise Suppression ..........................................................................................................................26
3.3.10 Matrix .............................................................................................................................................26
3.3.11 High & Low Pass Filter ..................................................................................................................27
3.3.12 Delay..............................................................................................................................................28
3.3.13 Output ............................................................................................................................................28

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3.3.14 USB Interface ................................................................................................................................28
3.4 Setting Menu ..........................................................................................................................................30
3.4.1 File Menu.........................................................................................................................................30
3.4.2 Device Setting .................................................................................................................................31
3.4.3 GPIO Setting....................................................................................................................................31
3.4.4 Group Setting ..................................................................................................................................34
3.4.5 Panel Setting ...................................................................................................................................35
3.4.6 Help Menu .......................................................................................................................................37
4. Control ............................................................................................ 38
4.1 External Control Programmer ................................................................................................................38
4.2 Control Protocol......................................................................................................................................38
4.3 Serial Port-to-UDP (RS232 To UDP) .....................................................................................................40
5. FAQs............................................................................................... 41
Appendix A: Module ID Distribution .................................................... 42
Appendix B: Module Parameter Types (1).......................................... 43
6. After-Sales ...................................................................................... 45
7. Warranty.......................................................................................... 46

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Preface
Read this user manual carefully before using the product. Pictures shown in this manual are for reference
only. Different models and specifications are subject to the real product.
This manual is only for operational instruction, please contact the local distributor for maintenance
assistance. The functions described in this version are updated as of September 2021. In the constant effort
to improve the product, we reserve the right to make functions or parameters changes without notice or
obligation. Please refer to the dealers for the latest details.
FCC Statement
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. It 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 commercial
installation.
Operation of this equipment in a residential area is likely to cause interference, in which case the user at
their own expense will be required to take whatever measures may be necessary to correct the interference.
Any changes or modifications not expressly approved by the manufacturer would void the user’s authority to
operate the equipment.
Do not dispose of this product with the normal household waste at the end of its life cycle. Return it to a
collection point for the recycling of electrical and electronic devices. This is indicated by the symbol on the
product, user manual or packaging. The materials are reusable according to their markings. By reusing,
recycling or other forms of utilisation of old devices you make an important contribution to the protection of
our environment. Please contact your local authorities for details about collection points.

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1. Hardware
1.1 Safety Instructions
Safety Instructions
Important safety instructions:
1. Read these instructions.
2. Keep these instructions secure.
3. Pay attention to all warnings.
4. Follow all instructions.
5. Please keep the device away from water. The device cannot be exposed to water drips or water splashes; make
sure that there is no object with liquid near the device, such as a vase.
6. Please use dry cloth to clean the device.
7. Please do not block the vent. Please install the device based on the manufacturer's instructions.
8. Please do not install near any heat source, such as radiator, furnace, or other devices (including amplifiers) that
generate heat.
9. Please make use of a protective grounding connection to connect the device to the power socket. Please do not
use polarized plug or grounding plug. A polarized plug has two leaves, and one is wider than another. A grounding
plug has two leaves and a third ground terminal. The wide leaf or third ground terminal can provide safety for the
users. If the plug provided does not correspond with the power socket, please contact an electrician to replace the
old socket with a new one.
10. Protect the power cord so that it will not be trampled or jutted, particularly the plug, the socket and the
connections of cord and device.
11. Please use the accessories designated by the manufacturer.
12. Please only use a cart, a tripod, or a desk designated by the manufacturer, or sold together with the device. When
using a cart, please take care with the mobile cart / device to avoid injury from rollover.
13. Please unplug the device during a thunderstorm or during the idle period.
14. Please contact our qualified maintenance personnel to deal with all maintenance related issues. For example, the
power cord gets damaged, liquid has spilt over, or an object falls onto the device; the device is exposed to rainwater
or moisture; the operations are not correct, or the device completely fails.
The lightning logo (an equilateral triangle with an arrow) is used to make the users aware of the uninsulated
"dangerous voltage" within the product shell, which may cause electric shock. An equilateral triangle with an
exclamation mark is adopted to make the users understand the importance of the operations and maintenance
instructions given in the appendixes attached to the product.
Warning: In order to prevent electric shock, please do not use a polarized plug provided by a device with an
extension cord. The socket outlet cannot be inserted except for the sharp end.

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1.2 Audio Wiring Reference
Balanced Audio Connection
Any of these audio connections may occur on either input or output terminals.
Unbalanced Audio Connection
RCA audio connections and 1/4-inch TS audio connections are unbalanced connections. A multi-strand shielded
conductor may be installed on both ends of the unbalanced connection. In such a case, please note to join the
negative and shield conductors as indicated.

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1.3 Specifications
Alfatron ALF-DSP88-U
SPECIFICATIONS
Processor ADI SHARC 21489(x2)
Sampling rate/Digitalizing bit 48K/24bit
Input Gain 0 – 48dB in 3dB Steps
Phantom Power 48V
Frequency Response (20~20KHz) ±0.2dB
Maximum Level +24dBu
THD + Noise 0.003%@4dBu
Dynamic Range 110 dB
Background Noise (A-weighted) -91 dBA
Common Mode Rejection Ratio @60Hz 80dB
Channel Isolation @1KHz 108 dB
Input Impedance (Balanced Connection) 9.4KΩ
Output Impedance (Balanced Connection) 102Ω
System Delay <3ms
Inputs 8 Balance Line/Mic Inputs on Phoenix Connections
Outputs 8 Balance Line Outputs on Phoenix Connections
Audio Processing Functions
Acoustic Echo Cancellations (AEC)
Automatic Gain Control (AGC)
Noise Suppression
Auto Mixer
Matrix
8 Band Parametric EQ (Inputs & Outputs)
High / Low Shelf Filters
Expander
Compressor / Limiter
Feedback Suppressor
Delay
USB AUDIO
1 In – 1 Out
Control Options
IP based PC software and host control.
Third party control for RS-485 and RS-232.
GPIO
8 Channel Logic Output

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1.4 Mechanical
Space required:
1U (width * depth * height: 18.91″ x 9.5″x 1.72″ / 48.02 cm x 24.13 cm x 4.37 cm). The reserved head space is not
included in the depth.
An additional space at least 3 inches must be reserved for the connection of rear panel. The reserved depth depends
on the wire used and the connection mode.
Electrical Properties:
Maximum universal input power: 110-240 VAC, 50/60 Hz, 40 W.
Ventilation:
The recommended highest operating ambient temperature is 30℃/ 86℉.
Make sure that there is no obstruction on both sides (a gap of at least 5.08cm / 2 inches shall be reserved). Please do
not cover the thermal vents of the device with newspapers, a tablecloth, or any other objects.
1.5 Front Panel
Power: LED power indicator.
STATUS: The operational status indicator of the device.
USB AUDIO: USB soundcard (1-in-1-out), for connection to host PC.
MECHANICAL
Working Power AC110~240V 5Hz-60Hz
Maximum Power Consumption <40W
Rack Space Required 1U
Dimensions (Width x Depth x Height) 482 x 260 x 45mm
Shipping Weight 3KG

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1.6 Rear Panel
Power Source:
Power switch
Fuse
Power connector: (Supports 110 - 240V AC 50/60Hz, and supports a maximum power of 40W)
Ethernet Connector
10/100 Base-T Ethernet connector is used for IP-based PC software and host control, and third-party accessory
controller.
RS485
Used for the serial communication port Tx = sending or data output or Rx = receiving or data input that connects
to a third-party control device.
RS485 can be used for voice tracking control (or other output commands), or for bus input control. A central
command can be used to conveniently integrate it into your software.
Port setting: 115200 baud (default), 8 data bits, 1 stop bit, no parity, no flow control.
RS232
Used for serial communication; port Tx = sending or data output or Rx = receiving or data input that connects to
a third-party control device.
Port setting: 115200 baud (default), 8 data bits, 1 stop bit, no parity, no flow control.
GPIO
12-bit 3.81 mm terminal
8-channel logic output, with 4 pairs of universal grounding pins. After being activated, the logic output will be
low (0V), and the internal voltage will be high (5V) when not activated. You may directly power and light up
external LEDs. The logic output can be driven by the logic output control module in the device design. Polarity
and threshold can be set in the software.
2. Technology Overview
2.1 Introduction to DSP Technology
Audio Digital Signal Processors (DSP) are equipped with several core technical features to simulate the work of
an audio engineer. DSP-based audio management, routing, processing, and control is facilitated via a computer
running the GUI Software for the Audio DSP Hardware. This Manual mainly introduces the techniques used to
achieve this goal.
The Alfatron DSP Controller software is a Windows-based application, which is used to configure and control the
DSP hardware. The Alfatron DSP Controller has 16 built-in presets, and the modules and sequences for each
preset can be flexibly designed in accordance with the designer's requirements. Once the design is completed,
it can be saved for future use. The sequences and parameters of the DSP Controller's built-in processing
modules work with most application scenarios without needing any changes.

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The Alfatron DSP Controller is a full-feature application, including parameter adjustments and peripheral
accessory settings of all modules, such as RS232, RS485, and click-and-drag panel configuration etc. The most
interesting part is the user interface, which allows the engineer to customize the user interface so that the
integrator can edit it, or the onsite technicians or end users who have no idea of the relevant techniques can
operate it. Advanced security features make it possible for the end user to only access the controls allowed by
the engineer, or designer.
2.2 Audio Input Section
The Alfatron ALF-DSP88-U supports up to 8 fixed analogue audio inputs, which can be connected via removable
balanced phoenix connectors. The analogue input section supports microphone or line-level signals whose
nominal levels range from 0dBu to +48dBu in 3dBu steps.
+48VDC phantom power can be independently switched on/ off for each input.
Preamp gain and phantom power can be conveniently controlled via the DSP Controller.
The Analogue to Digital (A/D) converter, or ADC, adopts an advanced 24-bit 256X sampling converter.
Analogue to Digital (A/D) Converter Technical Specs:
Sampling rate: 48kHz
THD+N: 105dB
Dynamic range: 120dB
Audio format: 24Bit MSB TDM