SY SY-1A-25R User manual

SY 1A-25 Amplifiers and LVC
SY Electronics Ltd., Unit 7 Worrall Street, Salford, Greater Manchester, M5 4TH
Tel: [phone] – Web: sy.uk
Installation Guide
SY-1A-25R
SY-1A-25W
SY-LVC
Description
25W per Channel Stereo Power Amplifier, Rack Mounting
25W per Channel Stereo Power Amplifier, Wall Mounting
Stereo Line Volume Controller

SY 1A-25 Amplifiers and LVC
sy.uk 2
The SY Amplifier range and Line Volume Controller provide a means of controlling the
volume level of any analogue signal with the option to directly drive stereo speakers.
The following table details the main features of each of the SY amplifier products.
SY-1A-25R, SY-1A-25W and SY-LVC Features
Parameter
SY-1A-25R
SY-1A-25W
SY-LVC
Line Inputs
2 (balanced)
2 (balanced)
2 (balanced)
RS232 Control
Yes
Yes
Yes
Front Panel Volume
Control
No
Yes
No
Line Outputs
None
None
2 (balanced)
Speaker Outputs
2 (Class D)
2 (Class D)
None
Output Power Rating / ch
25W @ 8R
25W @ 8R
Not applicable
Mode Switch
Yes
Yes
No
SY-1A-25R
SY-1A-25W

SY 1A-25 Amplifiers and LVC
3www.sy.co.uk
SY-LVC
Using the SY Amplifiers
Only the SY-1A-25W has a panel mounted volume control, both the SY-1A-25R and
SY-LVC can only be controlled by using RS232 commands.
At power up, all the amplifier models start at a low volume level by default. An RS232
command will be required to set the desired the volume level after the unit has been
powered up.
The SY-1A-25R and SY-1A-25W are intended to be used as power amplifiers to drive
stereo loudspeakers with a minimum rating of 25W at 8R per channel.
Connecting the Inputs
Both the inputs are balanced inputs, +ve, -ve and Gnd. However, if the audio signal is
unbalanced the signal should connect to the +ve input and Gnd, with the –ve input also
connected to Gnd, as shown in the following diagram:
Connecting the Outputs
The outputs are either Class D speaker outputs for the SY-1A-25R and SY-1A-25W, or
balance analogue audio outputs for the SY-LVC. In each case the outputs must never
be connected to any ground or 0V line, as doing so will damage the Class D output
drivers of the SY-1A-25R and SY-1A-25W amplifiers.

SY 1A-25 Amplifiers and LVC
sy.uk 4
If you require only unbalanced audio from the SY-LVC, only use the +ve output and the
G terminals to connect to the next item of audio equipment for each output channel.
Mode Switch
SW1 of the Mode Switch sets the amplifier into either stereo or mono mode. When in
stereo mode, the two inputs are separate and set to the same volume level. In mono
mode the two inputs are summed together and present to both outputs as a balanced
mono signal.
SW2 of the Mode switch on the SY-1A-25W can switch the front panel control between
adjusting the volume, or to allow setting of the stereo balance.
Switch
Off
On
SW1
Stereo
Mono
SW2 (1A-25W only)
Volume Control
Balance Control
1A-25W Bargraph Modes from SW2 Setting
Volume control is indicated on the 1A-25W by having the LED bargraph start from the
lowest green LED.
Balance control is indicated on the 1A-25W by only having two LEDs lit that move up for
right balance and down for left balance.
RS232 Control
All the amplifiers and the line volume controller can be controlled using RS232
commands. The RS232 communication settings are:
57600 bps
8 data-bits
No parity
One stop bit
No handshaking
For all commands, the  represents the carriage-return character, 0x0d, and ˽
represents the space character, 0x20.
Operation
ASCII Command
Power on the amplifier
PWR=ON
Power down the amplifier
PWR=OFF
Raise the Volume Level
VOL˽UP
Lower the Volume Level
VOL˽DOWN
Set the Volume Level, where xxx is in
the decimal range 000 to 100
Note: All three digits are required
VOL=xxx
Mute On
MUTE=ON
Mute Off
MUTE=OFF
Mute Toggle
MUTE
Get Mute Status
MUTE?
Mono Mode On
MSM=ON
Mono Mode Off
MSM=OFF

SY 1A-25 Amplifiers and LVC
5www.sy.co.uk
Power Supply Input
Only use the power supply provided with the amplifier to ensure optimal results. Using
a power supply with less current output will cause the amplifier to reset to the normal
lower volume level as if the amplifier was just repowered in order to protect the outputs
and speakers.
Specifications
General
Power Supply
24V DC @ 3A for SY-1A-25R and SY-1A-25W
12V DC @ 1A for SY-LVC
Power Consumption
55 W max for SY-1A-25R and SY-1A-25W
0.6W for SY-LVC
RS232
57600, 8 data bits, 1 stop bit, no parity – No handshaking
Audio
Frequency Response
20 Hz to 20 kHz
Channel Separation
> 75 dB
Input Impedance
15 k ohms
Speaker Output (1A-25R & 1A-25W)
2 x 25 W into 8 ohms
THD+N (1 kHz at full power)
< 0.1%
Environmental
Operating Temperature
0 - 40 °C non condensing
Physical
SY-LVC
SY-1A-25R
SY-1A-25W
Dimensions (W x H x D)
82 x 26 x 43
108 x 41 x 75
146 x 86 x 18
Weight
85 g
200 g
170 g

SY 1A-25 Amplifiers and LVC
sy.uk 6
Safety Instructions
To ensure reliable operation of these products as well as protecting the safety of any
person using or handling these devices while powered, please observe the following
instructions.
1. ONLY USE the power supply provided. If an alternate supply is required, check the
voltage, polarity and that it has sufficient power to supply the device it is connected to.
2. DO NOT operate these products outside the specified temperature and humidity
range given in the above specifications.
3. Ensure there is adequate ventilation as these products generate heat while operating.
4. Repair of these products should only be carried out by qualified professionals as these
product contains sensitive devices that may be damaged by any mistreatment.
5. Only use these products indoors and in a dry environment. DO NOT allow any liquids or
harmful chemicals to come into contact with this product.
After Sales Service
1. Should you experience any problems while using these product, firstly refer to the
Troubleshooting section in this manual and/or your local dealer before contacting SY
Technical Support.
2. When calling SY Technical Support, please provide the following information:
Full Product Name and Model Number
Product Serial Number
Details of the fault and any conditions under which the fault occurs.
3. These products have a two year standard warranty beginning from the date of purchase
as stated on the sales invoice. For full details please refer to our Terms and Conditions.
4. The SY Product warranty is automatically void under any of the following conditions:
The product is already outside of its warranty period
Damage to the product due to incorrect usage or storage
Damage caused by unauthorised repairs
Damage caused by mistreatment of the product
5. Please direct any questions or problems you may have to your local dealer before
contacting SY Electronics.

SY 1A-25 Amplifiers and LVC
7www.sy.co.uk
NOTES:

SY 1A-25 Amplifiers and LVC
sy.uk 8
NOTES: