Box-Design Pro-Ject Amp Box S3 User manual

INSTRUCTIONS FOR USE
Pro-Ject Amp Box S3

©
Pro-Ject Audio Systems · Amp Box S3 · Revision 2022.01.03
2
Dear music lover,
thank you for purchasing a Pro-Ject Audio Systems amplifier.
In order to achieve maximum performance and reliability you should study these instructions for use carefully.
Warning of a hazard for the user, the unit or possible misuse.
Important notice.
Safety instructions
AC outlet voltages vary from country to country. Before connecting to the mains, make sure that the
voltage in your area meets the voltage requirements printed on the power supply. The power cord is
used to disconnect the unit from the mains. Make sure that the power cord is easily accessible at all times.
Never handle the device, the power cord/power supply while your hands are wet or damp.
Avoid letting liquids enter the device or the power supply. Never place any item containing liquid, such
as a flower vase on or near the device. Never spill any liquid on the device or the power supply. Never
place any naked flame sources, such as lighted candles on or near the device. The product shall not be used
in damp or wet locations, next to a bathtub, sink, swimming pool or any other similar conditions.
Connectors
Make all connections whilst the amplifier is disconnected from the mains. Take care to connect the left
and right channels correctly. The right channel is usually marked red, the left channel black or white.
Make sure the polarity of the connection is correct at each end of the cables.
Only connect one loudspeaker with an impedance not less than 4 ohms per channel.
Never use any other power supply than the one supplied with the unit.
Connection to the preamplifier
The Input sockets marked Left /Right are for connecting the cables from your pre-amp or AV processor. Signal
can be relayed further via Jack socket 3.5mm marked Out.
Connection to the speakers
The output terminals accept loudspeaker cables terminated with 4mm ∅Banana plugs, spades connectors or
naked wire.
Mains power connection
Connect the low voltage plug from the power supply to the Power DC 20V socket of the amplifier before
connecting the power supply to the mains.

©Pro-Ject Audio Systems · Amp Box S3 · Revision 2022.01.
03
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Remote power on
The amplifier can be switched on & off via the 12V DC 2,5mm socket marked Trigger In. Cables are available
as accessories. The remote power-on signal can be relayed to further units via the Trigger Out socket.
Pay attention to the correct polarity of the cable.
Only connect the remote power cable when the pre- and power amplifier are disconnected from the
mains. Failure to observe can result in damage to the circuit.
To switch on from standby or to standby
The push button on the front panel of the unit alternately turns the power on or returns it to standby mode. The
blue LED above the stand-by push button shows that the unit is switched on.
Technical specifications Pro-Ject Amp Box S3
Power output: 2 x 23W/40W at 8 ohms/4 ohms (1% THD)
Peak power: 2 x 50W at 4 ohms
Frequency response (20Hz - 20kHz): <-0,7dB at 4 ohms
Channel separation: >-68dB at 20kHz
Signal to noise ratio: 87dBV (100dBV - 'A' weighted) at 4ohms
THD+N: <0,02% at 10W at 4 ohms
Gain: 31 dB
Line input sensitivity: 360mV
Pre in: 1 pair RCA
Bypass Output: Jack socket 3,5mm stereo
Input impedance: 25 kohms
Speaker connectors: 4mm ∅banana plugs, spades connectors or naked wire
Trigger: 12V DC switching voltage, 2-pole co-axial ∅2,5mm co-axial jack
Outboard power supply: 20V/3A DC, suitable for your country's mains supply
Dimensions W x H x D (D with sockets): 103 x 36 x 118 (136) mm
Weight: 385 g without power supply
Service
Should you encounter a problem which you are not able to alleviate or identify, please contact your dealer for
further advice. Only when the problem cannot be resolved there should the unit be sent to the responsible
distributor in your country.
Warranty
The manufacturer accepts no responsibility for damage caused by not adhering to these instructions
for use. Modification or change to any part of the product by unauthorized persons release the
manufacturer from any liability over and above the lawful rights of the customer.
Copyright, trademarks
Pro-Ject Audio Systems is a Registered Trademark of
H. Lichtenegger.
This guide was produced by Pro-Ject Audio Systems
Copyright ©2022. All rights reserved.
The information was correct at the time of going to
press
. The manufacturer reserves the right to make
changes to the technical specification without prior
notice as deemed necessary to uphold the ongoing
process of technical development.