Pro-Ject Phono Box DS3 B Premium Balanced and Discrete MM or MC Phono Preamplifier Instruction Manual

: June 4, 2024
: Pro-Ject

Table of Contents

Phono Box DS3 B Premium Balanced and Discrete MM or MC Phono Preamplifier
Safety instructions
Connectors
Settings
Technical specifications Pro-Ject Phono Box DS3 B
Warranty
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BY PRO-JECT AUDIO SYSTEMS
INSTRUCTIONS FOR USE
Pro-Ject Phono Box DS3 B

Phono Box DS3 B Premium Balanced and Discrete MM or MC Phono Preamplifier

Dear music lover,
thank you for purchasing a Pro-Ject Audio Systems phono 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 supply is used to disconnect the unit from the mains. Make sure that the power supply is easily accessible at all times. Never handle the device, the 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 phono amplifier is disconnected from the power supply.
Take care to connect the left and right channels correctly. The right channel is usually marked red, the left channel is black or white.
Do not connect the phono amplifier output to a phono input (sometimes labeled gram, disc, or RIAA) on the amplifier.
Never use any other power supply than the one supplied with the unit.

Connecting the record player
Connect the tonearm signal lead to the In (5-pin mini XLR, XLR or RCA) of the phono amplifier. If you connected the lead to the RCA input, please also connect the grounding wire to the screw terminal of the Phono Box.
Connection to the amplifier
Connect the Output (Balanced XLR or RCA) of the phono amplifier to line input (such as AUX, CD, Tuner, Tape, or Video) on your amplifier.
RCA and XLR outputs are separated and both play all the time. 2 amplifiers can be connected.

Mains power connection and methods to switch the unit on and off
Connect the low-voltage plug from the power supply to the Power 18V socket of the preamplifier before connecting the power supply to the mains.

Using front pushbutton to switch on or into standby
The pushbutton on the front panel of the unit alternately turns the power on or returns it to standby mode. The blue LED on the front panel shows that the unit is powered on. If a trigger signal is present, the unit can’t be switched off by the pushbutton.
Remote power on – triggers
The unit can be switched on via other Box Design components when a 12V trigger voltage is present at the 2.5mm socket marked Trigger Input. Special power-on cables (polarity: ) in diverse lengths are + available as accessories. The remote power-on signal can be relayed to further units via the Trigger Output socket. When the 12V trigger signal is switched off, the unit will also switch off.

**** Trigger cables may only be plugged into the sockets when the unit is disconnected from the power supply and from the mains. Failure to do so may result in damage to the unit.

Settings

Input
Selects balanced (5-pin mini XLR or XLR) or unbalanced (RCA) input.
2 turntables can be connected to the preamplifier and this button acts as input selector, settings for each input are stored in memory.

Cartridge settings
The three push buttons on the right-hand side are used to set input impedance (Loading Ohms), input capacitance (Loading pF), and input gain (Gain dB).
The button Loading Ohms must be set to Variable for using a rotary controller. Use the rotary controller to set input impedance to the desired value (10Ω- 1000Ω). ONLY IMPORTANT FOR LOW-OUTPUT MC CARTRIDGES!
To find out which type your cartridge is please consult the literature accompanying your cartridge. The literature for cartridges should also specify the correct input impedance and input capacitance, into which the cartridge is designed to work. If in doubt, please consult your dealer.

Examples:
Ortofon 2M Red (MM):
Input impedance 47kohms, Input capacitance 147pF, Input gain 40dBOrtofon X5-MC (High-Output MC):
Input impedance 47kohms, Input capacitance 367pF, Input gain 40dB
Ortofon Quintet Red (Low-Output MC):
Input impedance 50 ohms (Set Loading Ohms to variable & set 50 ohms with the rotary encoder), Input
capacitance – Any setting (not relevant for low-output MC), Input gain 60dB

Subsonic
The push button turns the subsonic filter on and off. The LED shows that the filter is turned on.

Technical specifications Pro-Ject Phono Box DS3 B

Input impedance:	Stepless 10 – 1000 ohms or fix 47 kohms
Input capacitance:	50, 150, 300, 400pF
Gain (+6dB using XLR Out):	40, 45, 50, 55, 60, 65dB
Signal / Noise ratio MM (40dB):	104dBV, 111dBV – ‘A’ weighted
Signal / Noise ratio MC (60dB):	85dBV, 91dBV – ‘A’ weighted
THD at 1 kHz:	<0,001% MM, < 0,004% MC
HD (20Hz-20kHz):	<0,005% MM, < 0,01% MC
RIAA-equalization curve accuracy:	<0,25dB / 20Hz – 20kHz
Subsonic filter:	at 20Hz with 18dB/octave
Input:	1x 5-pin mini XLR / 1x pair XLR / 1x pair RCA phono sockets
Line-level output:	1x pair RCA, 1x pair XLR
Wiring XLR sockets:	1 ground, 2 “hot” and 3 “cold”
Trigger In/Out:	12V on/off detector
Power supply DC:	18V/500mA
Power consumption:	18V/290mA DC, <0.5 W in standby
Dimensions:	206 x 70 x 194 (205 with sockets) mm (W x H x D)
Weight:	1480g without power supply

Potential incorrect use and fault conditions

No signal on one or both channels:
No connection between the player and the phono amplifier or amplifier. This could be due to a faulty plug, broken wire or solder joint, or simply a loose plug/socket connection.
Strong hum:
No earth connection from cartridge or arm, or arm cable to phono amplifier, or earth loop.
Output too quiet or too loud, or distorted:
Input gain incorrectly set – input overloading or insufficiently amplified.

Service
Should you encounter a problem that you are not able to alleviate or identify, please contact your dealer for further advice. Only if the problem cannot be resolved there, the unit should 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 changes 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© 2021. 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.