Lyngdorf Audio SDAI 2175 User manual

Owner´s manual
SDAI 2175
Semi Digital Amplifier Integrated

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3
Table of Contents
Operating Voltage 4
Unpacking the SDAI 2175 4
Serial Number Registration 4
Introduction 5
Accessories 6
Front Panel 7
- Controls 7
- Display 8
Rear Panel 9
Menu system 10
Menu Tree 11
- RELVOL - Relative Volume 11
- SENSIT - Sensitivity 11
- BRIGHT - Brightness 11
- IR RMT - IR Remote 11
- INPTXT - Select Input Text 11
- LNKID - Link Address 12
- LNKSP - Link Comm. Speed 12
- BAL LR - Balance Left Right 12
- DEFVOL - Default Volume 12
- MAXVOL - Maximum Volume 12
Software 13
Connectors 14
- Mains Connector 14
- Loudspeaker connectors 14
- Input connectors 14
- Balanced inputs 14
- Unbalanced inputs 14
- Trigger connectors 15
Cleaning and Maintenance 15
Technical Specifications 16
- Audio 16
- Protection 17
- Mains 17
- Trigger 17
- Mechanical 17
Technical Assistance 18
Manual version 10-05-07

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Operating Voltage
The SDAI 2175 is available in a version for 115V mains voltage and in a version for 230V mains voltage.
Check the label on the SDAI 2175 rear panel and verify you have the version with the proper voltage for
your area.
The 115V version requires a mains voltage of 100V-120V at 50-60Hz with a current rating of 8A.
The 230V version requires a mains voltage of 200V-240V at 50-60Hz with a current rating of 4A.
The mains voltage setting for your SDAI 2175 can be changed ONLY BY A QUALIFIED ENGINEER.
Connect the power input only to the AC source printed on the label. The warranty
will not cover any damage caused by connecting to the wrong type of AC mains.
Unpacking the SDAI 2175
Carefully remove the unit and accessory kit from the carton, visually check for shipping damage. Contact
both the shipper and Lyngdorf Audio immediately if the unit bears any sign of damage from mishandling.
All Lyngdorf Audio equipment is carefully inspected before leaving our factory.
Keep shipping carton and packing material for future use or in the unlikely event that
the unit needs servicing. If this unit is shipped without the original packing, damage
could occur and void the warranty.
Serial Number Registration
Please record the serial number of your amplifier here for future reference. The serial number is printed
on the label on the SDAI 2175 rear panel. You will need this serial number, should you ever require
service for your SDAI 2175 power amplifier.
SDAI 2175 serial number: _____________________

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Introduction
Lyngdorf SDAI 2175 is a compact, high performance semi digital integrated switch-mode amplifier utilizing
some of the circuit topologies originally developed for the Lyngdorf Millennium amplifier. Due to the
switch-mode topology, with an efficiency of up to 85%, the SDAI 2175 will provide its output power
with minimal heat dissipation. A massive power supply with a 650VA toroid transformer and more than
40000uF capacitors ensures that the SDAI 2175 can deliver the current to drive even the most demand-
ing loudspeakers.
The SDAI 2175 has 2 gold-plated XLR connectors accepting balanced input signals and 6 stereo inputs
with 2 gold-plated RCA connectors for unbalanced signals. The SDAI 2175 has a stereo tape out of the
selected line level input signal and pre out of the selected input signal after the volume control as either
balanced signal from the gold-plated XLR connectors or unbalanced from the gold-plated RCA connec-
tors.
The volume control is implemented as a high precision digital controlled analog attenuation in 0.1 dB
steps over a 100 dB range. Input selection is performed via precision relays with double gold plated
construction of the contact set. These kind of relays are normally only used in expensive measurement
equipment for high linearity and low losses.
All controls can be operated from the front panel via the logical user interface or by use of the remote
control. Or as an option the setup and operation can be performed via a PC interface.
The input signal is fed to the volume control circuit via an AC coupled true instrumentation type input
amplifier. Except for this AC coupling, the SDAI 2175 is fully DC coupled with no bypass capacitors or DC
servos to degrade the performance. The protection circuitry in the SDAI 2175 shuts down the unit in case
of over-temperature, DC voltage on the outputs and too high output current. The amplifier will resume
normal operation when the fault condition is no longer present.
A trigger output on a 3.5mm jack connector allows the SDAI 2175 to control one or more SDA2175’s
power condition.

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Accessories
You should find the following accessories included:
Mains cord This manual
12 3
456
7
digital info
analog
A/B random repeat
AMP
channel
ENTER
volume
RCS CD TUNER
menu
8
0
9
Programming cable
Remote control

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Front Panel
Controls
The buttons/controls on the front panel of the SDAI 2175 can all be used either with direct presses on
the front or by operating the similar keys on the included remote control. All keys on the front except for
the Mains switch (1) can be found on the remote control as well.
1. Mains switch
Turns the power to the unit On or Off.
2. Power
Changes the SDAI 2175 mode between Standby and Active.
3. Menu
Toggles Menu mode on/off.
4. Enter
Activates sub menus for active changes.
5-11. Input selectors
Selects active input, or in menu system select input to change.
12. Volume
-/+ indicates decrease and increase in volume control or in menu mode toggles sub menus, or in menu
active mode toggles parameters.
13. Mute
Toggles mute for SDAI 2175.

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Display
12 3 4 5 6 7
1. OPERATE
Indicates the operational status of the SDAI 2175.
Off:• The SDAI 2175 is in standby mode.
Flashing:• The SDAI 2175 is in the soft-start phase or the
protection circuit is engaged.
On:• The SDAI 2175 is operating normally.
2. POWER
Illuminated whenever the power is applied to the SDAI 2175 and the mains switch is ON.
3. MENU
Indicates the Menu system is operative of the SDAI 2175.
Off:• The SDAI 2175 is in normal mode.
Flashing:• The SDAI 2175 is in menu active mode.
On:• The SDAI 2175 is in menu select mode.
Menu active mode indicates the menu button (3) have been pressed and the different menus can be
either toggled by pressing -/+ (12) or selected for changes with enter (4).
4. 1-7
Illuminates active input
5. 14 Segment display
Main menu system information 6*14 segment display.
6. VOLUME
3 digits indicating Volume control setting from 00.0 to 99.9 – in dB’s
7. MUTE
Illuminated when Mute is active

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Rear Panel
1-6. Input
RCA unbalanced input channel 1-6.
7. Input
Balanced stereo input channel 7.
8. Tape Out
Line output of selected input.
9. Pre Out
Regulated output after volume control of selected input.
10. Pre Out Bal
Balanced regulated output after volume control of selected input.
11. Trigger Out
DC Trigger out for remote start of SDA 2175 power amplifiers or similar equipment.
12-13. Input
RS232 communication connectors for communication with PC.
14. Loudspeaker Connectors
Stereo Loudspeaker output
15. Mains socket

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Menu system
The Menu system of the SDAI 2175 can be used for setting up the amplifer for nearly all everyday situations.
The only feature which can not be changed from the menu system is custom naming of the input texts
which can only be performed from the SDAI Pack PC setup program available for download from www.
lyngdorf.com.
The menu system of the SDAI2175 can be entered by pressing the Menu key (3) where after the menu
indicator will be illuminated. The volume control keys (12) now changes status from being volume control
keys to be sub menu selectors for the menu system. Pressing the keys changes between the different
menus seen in fig.1.
When the wanted menu system is found, it can be activated with the Enter key (4). When active the
menu LED starts blinking and the parameters for the active setting can be changed with the volume
control keys (12). The changes can be confirmed and stored by pressing the Enter key (4) or the changes
can be skipped by pressing menu which exit’s the menu system again.
The menu system is shown on Fig. 1, and the different sub menus will be explained in the following.

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Menu Tree
SDAI 2175 Main Menu
RELVOL
Relative Volume
SENSIT
Sensitivity
BRIGHT
Brightness
IR RMT
IR Remote
INPTXT
Select Input Text
LNKID
Link Address
LNKSP
Link Comm. Speed
BAL LR
Balance Left Right
DEFVOL
Default Volume
MAXVOL
Maximum Volume
Fig. 1.
RELVOL - Relative Volume
RELVOL
Relative Volume
Relative volume for the active input. Fine tuning of the volume control for each input relative to the
global setting. The Sensitivity can be adjusted +/-6dB in 0.1 dB steps.
SENSIT - Sensitivity
SENSIT
Sensitivity
Input amplifier sensitivity 0 or +6 dB for the active input. Used for increasing the sensitivity for weak
sources in the preamplifier section without increasing noise level.
BRIGHT - Brightness
BRIGHT
Brightness
Brightness of Display from 0 (Display off) to max intensity 4.
IR RMT - IR Remote
IR RMT
IR Remote
Enable / Disable of remote control, Remote can be disabled if the SDAI 2175 is controlled over RS232
interface.
INPTXT - Select Input Text
INPTXT
Select Input Text
Selection of input text for the active input. Selection can be chosen between a range of predefined
strings or from 7 user defined strings which can be entered with the Lyngdorf SDAI 2175 Control soft-
ware.

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LNKID - Link Address
LNKID
Lind Address
Link ID adress in the Lyngdorf network. Address 0 is reserved, address 1 is used for masters in the
network, so applicable addresses are from 2-255.
LNKSP - Link Comm. Speed
LNKSP
Link Comm. Speed
Link Communication speed 9600/57600 Baud. Normal Lyngdorf interconnect speed is 57600 Baud.
BAL LR - Balance Left Right
BAL LR
Balance Left Right
Fine tunes balance of level from Left to Right speaker +/-6dB in 0.1 dB step.
DEFVOL - Default Volume
DEFVOL
Default Volume
Sets default volume when the amplifier comes out of standby.
MAXVOL - Maximum Volume
MAXVOL
Maximum Volume
Maximum volume the user can select, used as a safety feature to prevent excessive volume levels.

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Software
Lyngdorf Audio supplies control software for remote control of the SDAI 2175 and setup of the Input text
system. Please check the Lyngdorf audio web site for download of the newest version at http://www.
Lyngdorf.com
The SDAI 2175 firmware can be upgraded using the ‘Lyngdorf Serial Load, software upgrade tool’ this is
in the PC package available from www.Lyngdorf.com
Follow the upgrade steps to bring the product into boot mode. Only one device should be connected to
the PC when upgrading the firmware.
Upgrade steps:
Make sure that a serial cable is connected between PC and amplifier or CD.
Select File to upload.
Check Comm Adress and COM port
Click ´Open Comm port´.
Start Amplifier or CD in boot mode.
Upload new software
Wait for Amplifier or CD to Initialize
Bootmode:
Turn power Off on the front button.
Press both volume buttons simultaneously and hold them while turning On the power.
Release both volume buttons and SDAI 2175 is in bootmode.
1.
2.
3.
4.
5.
6.
7.

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Connectors
Mains Connector
Mains voltage to the SDAI 2175 is applied via an IEC320 type connector. The supplied cable with safety
ground should be used to connect the SDAI 2175 to a mains outlet.
Connect the power input only to the AC source printed on the label. The warranty
will not cover any damage caused by connecting to the wrong type of AC mains.
Always disconnect the SDAI 2175 from the mains before changing any connections
to its inputs or outputs.
Loudspeaker connectors
The SDAI 2175´s loudspeaker connectors accept banana plugs, spades or bare wire ends up to 5 mm in
diameter. Connect the wires from each loudspeaker to each channel’s + and – terminals. Do not make
any other connections to the output terminals. The loudspeaker cable is inserted into the slot in the loud-
speaker terminal, and the terminal is tightened firmly.
Always disconnect the SDAI 2175 from the mains before changing any connections
to its inputs or outputs.
Make sure that no conductive part of the speaker wiring is accessible. Do not con-
nect loudspeakers with uninsulated terminals.
When the SDAI 2175 is operating, there is 35V DC on its output terminals with reference to ground.
Do not connect the output from the amplifier to any other amplifier’s output or
any other voltage source. Do not attempt to operate the amplifier in bridged mono
mode.
Input connectors
The SDAI 2175 has input connectors for both balanced (XLR) and unbalanced (RCA) signals. The input
impedance of the balanced input 7 is 10 kOhm for the unbalanced input 1-6 the input impedance is
100kOhm.
Balanced inputs
The balanced XLR inputs are wired in accordance with IEC268:
Pin 1: Chassis and ground.
Pin 2: Hot (+).
Pin 3: Cold (-).
Shell: Chassis and ground.
Unbalanced inputs
The unbalanced RCA inputs are wired in accordance with normal practice:
Shell: Chassis and ground.
Pin: Hot (+).

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Trigger connectors
The SDAI 2175 is equipped with a TRIGGER OUT 3.5mm mono jack connector. The Trigger signal is a
12V short circuit protected output signal for powering up external equipment when the SDAI 2175 is on,
e.g. remotely connected SDAI 2175 power amplifiers or active subwoofers.
Cleaning and maintenance
Always unplug the unit from the electrical outlet before cleaning.
This unit does not require any regular maintenance except to keep its exterior clean. Simply wipe its exte-
rior with a clean soft cloth. A small amount of non-abrasive cleaner may be used on the cloth to remove
any excessive dirt or fingerprints. Do not use abrasive cleaners or cleaners containing liquid solvents.

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Technical specifications
Audio
Parameter Value Note
Balanced input connectors 3 pin XLR, gold-plated. Case=Gnd, Pin1=Gnd,
Pin2=Hot(+), Pin3=Cold(-)
Balanced input impedance 10kOhm AC-coupled.
Balanced input CMRR 40dB 20Hz-20kHz.
Unbalanced input connectors RCA (phono) jack, gold-plated. Case=Gnd, Tip=Hot(+)
Unbalanced input impedance 100kOhm AC-coupled
Tape Out output impedance 75 Ohm Gain 0 dB ref. active input
Pre Out output impedance 75 Ohm unbalanced
100 Ohm balanced
Gain According to volume con-
trol setting. 88 dB = 0 dB with
sensitivity 0 dB and rel. volume
0 dB
Max. input voltage ±12Vp AC, 0-20V DC.
Input sensitivity 2V (1V with high sens.) 200W/8ohms
Voltage gain 26dB
Output connectors 4 insulated binding posts, gold-
plated.
Will accept bare wire ends of up
to 5 mm diameter.
Output power, 8ohms 2*200W 1KHz, 1% THD+N
Output power, 4ohms 2*375W 1KHz, 1% THD+N
Nominal load impedance 4 Ohms-8 Ohms It is safe to operate the amplifier
with no load.
Frequency response 0.3Hz-33kHz -3dB points, 8ohms load.
Frequency response -0dB/+0.2dB 20Hz-20kHz, 8ohms load
Frequency response -0.2dB/+0dB 20Hz-20kHz, 4ohms load
Output impedance 0.035 Ohms 20Hz-1kHz
Output impedance 0.4 Ohms 20kHz
THD+N, 1W/8ohms 0.004% A-wgt.
THD+N, 1W/4ohms 0.006% A-wgt.
THD+N, 100W/8ohms 0.01% A-wgt.
THD+N, 180W/8ohms 0.07% A-wgt.
THD+N, 375W/4ohms 0.07% A-wgt.
S/N ratio 113dB A-wgt. Ref. 200W/8ohms.
Channel separation 84dB 1kHz, 200W/8ohms.
Peak output current ±40A
Output common mode voltage 35V DC Ref. Ground. The amplifier can
not be used in bridged mono
mode.
Output DC voltage ±5 mV
All audio measurements, except frequency response, are measured with a 20 kHz low-pass filter in ac-
cordance with AES-17.

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Protection
Parameter Value Note
Grounding Mains earth, chassis and audio
ground are connected internally.
Output short circuit current ±40A
Output DC voltage ±5V @ <0.1Hz
Over temperature All heat sinks and mains-trans-
former.
Auto resetting thermal fuse in
mains transformer.
Mains
Parameter Value Note
Mains input connector IEC 320 cold type Mains lead supplied.
Mains voltage range 100-120V AC, 50–60Hz 115V version
Mains voltage range 200-240V AC, 50-60Hz 230V version
Internal mains fuse 8 Amp 115V version
Internal mains fuse 4 Amp 230V version
Power consumption 1.5 W STANDBY mode.
Power consumption 35 W OPERATE mode, no output.
Power consumption 116 W 2*37.5W/4ohms.
Power consumption 820 W 2*300W/4ohms.
Trigger
Parameter Value Note
TRIGGER OUT connector 3.5mm (1/8”) mono jack Case=Gnd, Tip=Input
TRIGGER OUT Voltage 12V DC Short circuit protected
Mechanical
Parameter Value Note
Width 450mm (17.72”)
Depth 355mm (13.98”) Including loudspeaker connec-
tors.
Height 100mm (3.94”) Including feet.
Net weight 13.0Kg (28.66lb.)
Shipping weight 16.0Kg (35.27lb.)

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Technical Assistance
For latest version of control software, newest version of this document and ‘Questions and Answers’,
please check the ‘Support’ section on the Lyngdorf Audio website.
If you have any problems with or questions regarding your Lyngdorf Audio product, please contact
your nearest Lyngdorf Audio representative or:
Lyngdorf Audio
Denmark
E-mail: [email protected]
Web: http://www.lyngdorf.com

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www.lyngdorf.com