Pro-Ject Phono Box RS2 - Instructions for Use

Important Notices and Safety Instructions

⚠ Warning of a hazard for the user, the unit, or possible misuse.

ⓘ Important notice.

AC outlet voltages vary by country. Before connecting to the mains, ensure your area's voltage meets the requirements printed on the power supply. The power supply serves to disconnect the unit from the mains; ensure it is easily accessible. Never handle the device or power supply with wet or damp hands. Avoid letting liquids enter the device or power supply. Do not place items containing liquid, such as flower vases, near the device. Never spill liquid on the device or power supply. Do not place naked flame sources, such as lighted candles, near the device. The product is not intended for use in damp or wet locations, such as next to a bathtub, sink, or swimming pool.

Connectors

Make all connections while the phono amplifier is disconnected from the power supply. Ensure correct connection of left and right channels; the right channel is typically marked red, and the left channel black or white. Do not connect the phono amplifier's output to a phono input (often labeled 'gram', 'disc', or 'RIAA') on another amplifier. Always use the supplied power supply unit.

Diagram Description: The rear panel features connection terminals. On the left, there are 'Outputs' with RCA and XLR connectors, and 'Inputs' with RCA and XLR connectors. On the right, there is a 'Power' socket labeled '20V ='. The inputs are labeled 'Left' and 'Right'.

Connecting the Record Player

Connect the tonearm signal lead to the 'Input' of the phono amplifier. The unit offers two inputs (refer to the Input section). The grounding wire may be connected to the screw terminal if hum problems are encountered when using the record player.

Connection to the Amplifier

Connect the 'Output' of the phono amplifier to a line input (such as AUX, CD, Tuner, Tape, or Video) on your amplifier. RCA and XLR outputs are separated and active simultaneously. Two amplifiers can be connected.

Mains Power Connection

Connect the low voltage plug from the power supply to the 'Power 20V' socket of the preamplifier before connecting the power supply to the mains.

Switching On/Off

The rocker switch on the left side of the front panel turns the unit on or off. The blue LED above the switch indicates when the unit is powered on. The preamplifier uses an automatic mute function to eliminate clicks and pops during power on/off or settings changes.

Settings

The phono preamplifier offers various settings:

Diagram Description: The front panel displays controls for adjusting audio settings. From left to right, there are rotary knobs for 'Impedance MC' (with settings 10R, 40R, 100R, 400R, 600R, 1k, 800R), 'Gain' (with settings 40, 43, 46, 50 dB for MM, and 60, 63, 66, 70 dB for MC), 'Capacitance' (with settings 50, 100, 150, 200, 250, 300, 350, 400 pF), and 'Balance' (with a central '0' position and markings for +/- dB). There are also buttons for 'Input' selection (allowing connection of two turntables, with settings stored per input), 'Subsonic' (to turn the filter on/off), and 'Equalization' (to select RIAA or DECCA modes). A blue LED above the power switch indicates when the unit is on.

• Input: Selects balanced (XLR) or unbalanced (RCA) input. Two turntables can be connected, and this button acts as an input selector, storing settings for each input.
• Subsonic: Turns the subsonic filter on or off.
• Equalization: Selects the desired mode, RIAA or DECCA.
• Balance: Pressing the pushbutton illuminates the 'On' LED, allowing the balance between left and right channels to be adjusted using the 'Balance' potentiometer. The maximal channel difference is 4dB (from -2 dB to +2 dB).

Cartridge Settings

MM Cartridges

The Phono Box RS2 operates in MM mode with the first four MM Gain settings (40, 43, 46, 50 dB). Capacitance can be set in 8 steps from 50 to 400 pF. Impedance is fixed at 47kOhms in MM mode.

MC Cartridges

The Phono Box RS2 operates in MC mode with the second four MC Gain settings (60, 63, 66, 70 dB). Impedance can be adjusted using the potentiometer from 10 Ohms to 1000 Ohms. Capacitance is fixed at 50 pF in MC mode.

Consult your cartridge's literature for its type and recommended input impedance (for low-output MC) and input capacitance (for high-output MC and MM). If unsure, consult your dealer or manufacturer.

Examples of Typical Settings

• Ortofon Rondo Red (Low-Output MC): Gain 60dB, Impedance 10 Ohms. Capacitance is irrelevant for low-output MC cartridges; set to the lowest value (50 pF) when operating in MC mode.
• Ortofon 2M Red (MM): Gain 40dB, Capacitance 150pF, Impedance 47k Ohms (automatically selected in MM mode).
• Ortofon X5-MC (High-Output MC): Gain 40dB, Capacitance 350pF, Impedance 47k Ohms (automatically selected in MM/High-Output MC mode).

Technical Specifications Pro-Ject Phono Box RS2

• Input MM capacitance/impedance: 47kOhms
• Input MC impedance/capacitance: Stepless 10 Ohms – 1000 Ohms / 50pF
• MM Gain (+ 6dB using XLR sockets): 40, 43, 46, 50 dB
• MC Gain (+ 6dB using XLR sockets): 60, 63, 66, 70 dB
• Signal / Noise ratio MM (40dB): 82dB (RCA, XLR), 89dB A-wt (RCA, XLR) (10mV)
• Signal / Noise ratio MC (60dB): 66dB (RCA,XLR), 76dB A-wt (RCA,XLR) (1mV)
• MM THD+N: <0,005% (MM 40dB, 1kHz)
• MC THD+N: <0,04% (MM 60dB, 1kHz)
• MM THD: <0,0015% (MM 40dB, 1kHz)
• MC THD: <0,0024% (MM 60dB, 1kHz)
• RIAA-equalization curve accuracy: < +-0,4dB / 20Hz - 20kHz
• Subsonic filter: at 20Hz with 18dB/octave
• Input: 1 pair RCA/phono sockets, 1 pair XLR sockets
• Line-level output: 1 pair RCA/phono sockets, 1 pair XLR sockets
• Wiring XLR sockets: 1 ground, 2 “hot” and 3 “cold”
• Outboard power supply: 20V/3A DC
• Power consumption: 310mA DC, max. 350mA
• Dimension W x H x D (D with sockets): 206 x 72 x 200 (230) mm
• Weight: 1600 g without power supply

Potential Incorrect Use and Fault Conditions

• No signal on one or both channels: Check connections between player and phono amplifier or amplifier. This could be due to a faulty plug, broken wire, solder joint, or loose plug/socket connection.
• Strong hum: Ensure proper earth connection from cartridge or arm, or arm cable to phono amplifier, or check for earth loops.
• Output too quiet or too loud, or distorted: Input gain may be incorrectly set, leading to input overloading or insufficient amplification.

Service

Should you encounter a problem that cannot be alleviated or identified, please contact your dealer for further advice. If the problem cannot be resolved by the dealer, 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. Modifications or changes to any part of the product by unauthorized persons release the manufacturer from any liability beyond 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 © 2020. 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.