Arrel Audio ER-130 User manual

ER-130 Eurorack
Voltage Controlled
MID-SIDE Unit
User Manual
Issue 0.0

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 2
SAFETY INSTRUCTIONS
WARNING
Always follow the precautions listed below to avoid any possibility of serious injury or even death from electrical shock, short-
circuiting, damages, fire or other hazards. These precautions include, but are not limited to, the following:
•Do not expose the instrument to liquids and rain. Do not use it near water or in damp or wet conditions, or place
containers on it containing liquids. If any liquid seeps turn off the power and unplug the power cord from the AC outlet.
•Do not put burning items, such as candles, on the unit. A burning item may fall over and cause a fire.
•This instrument contains no user-serviceable parts. Do not open the instrument or attempt to disassemble or modify the
internal circuit.
•Never insert or remove an electric plug with wet hands.
•Check the electric plug periodically and remove any dirt or dust which may have accumulated on it.
•Do not place the power cord near heat sources such as heaters or radiators, and do not excessively bend or otherwise
damage the cord, place heavy objects on it, or place it in a position where anyone could walk on, trip over, or roll
anything over it.
CAUTION
Always follow the precautions listed below to avoid any possibility of serious injury or even death from electrical shock, short-
circuiting, damages, fire or other hazards. These precautions include, but are not limited to, the following:
•Do not connect the instrument to an electrical outlet using a multiple-connector. Doing so can result in lower sound quality, or
possibly cause overheating in the outlet itself.
•When removing the electric plug from the instrument or an outlet, hold the plug itself and not the cord. Pulling by the cord can
damage it.
•Remove the electric plug from the outlet when the instrument is not to be used for extended periods of time, or during
electrical storms.
•Do not place the instrument in an unstable position where it might accidentally fall over.
•Before moving the instrument, remove all connected cables.
•When setting up the product, make sure that the AC outlet you are using is easily accessible. If some trouble or malfunction
occurs, immediately turn off the power switch and disconnect the plug from the outlet. Even when the power switch is turned
off, electricity is still flowing to the product at the minimum level.
•When you are not using the product for a long time, make sure to unplug the power cord from the wall AC outlet.
•Use only the stand/rack specified for the instrument. When attaching the stand or rack, use the provided screws only. Failure
to do so could cause damage to the internal components or result in the instrument falling over.
Information for Users on Collection and Disposal of Old Equipment
This special symbol on the products, packaging, and/or accompanying documents means that used electrical and electronic products
should not be mixed with general household waste.
For proper treatment, recovery and recycling of old products, please take them to applicable collection points, in accordance with your
national legislation and the Directives 2002/96/EC.
By disposing of these products correctly, you will help to save valuable resources and prevent any potential negative effects on human
health and the environment which could otherwise arise from inappropriate waste handling.
For more information about collection and recycling of old products, please contact your local municipality, your waste disposal service
or the point of sale where you purchased the items.
[For business users in the European Union]
If you wish to discard electrical and electronic equipment, please contact your dealer or supplier for further information.
[Information on Disposal in other Countries outside the European Union]
This symbol is only valid in the European Union. If you wish to discard these items, please contact your local authorities or dealer and
ask for the correct method of disposal.

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 3
ARREL Audio Contacts
ARREL Audio
Via A. Mondadori, 7
00128 Rome – Italy
Tel [phone]
Fax: [phone]
Info: [e-mail]
Web: www.arrel-audio.com
Support: http://www.arrel-audio.com/support
ARREL Audio is continuously working to the improvement of its systems and related documentation.
In any case, we reserve the right to change the specifications without notice but in the respect to the current legislation.
Disclaimer:
The information contained in this manual has been carefully checked and we believed is accurate at the time of publication.
In any case, we do not assume any responsibility for inaccuracies, errors or omissions nor any liability for any loss or damage resulting either
directly or indirectly from use of the information contained in this manual.

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 4
TABLE OF CONTENTS
SAFETY INSTRUCTIONS...................................................................................................2
ARRELAudio Contacts........................................................................................................3
TABLE OF CONTENTS.......................................................................................................4
INTRODUCTION.................................................................................................................5
Housing................................................................................................................................5
ER-130 Front Panel Controls and Operations .....................................................................6
MODE SWITCH...............................................................................................................6
input L/R CONNECTORS ................................................................................................6
OUTPUT L/R CONNECTORS..........................................................................................6
CONTROL VOLTAGE (c.v.) CONNECTOR......................................................................6
Control voltage (c.v.)potentiometer...................................................................................6
ON SWITCH.....................................................................................................................6
PEAK LED........................................................................................................................6
STEREO WIDTH DISPLAY..............................................................................................6
MID AND SIDE INSERTS ................................................................................................6
STEREO WIDTH CONTROL knob...................................................................................7
LO-CUT PUSH BUTTON .................................................................................................7
LO-CUT CUT OFF FREQUENCY KNOB.........................................................................7
APPENDIXA: Front Panel...................................................................................................8
TECHNICAL SPECIFICATIONS..........................................................................................9

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 5
INTRODUCTION
ARREL Audio ER-130 Eurorack Voltage Controlled Mid Side Unit is the answer to all
stream creative needs for EURORACK synthesizers. Its features set it apart from other
similar products on the market due to a very high fidelity approach used for the design of
the electronics together with the use of high quality components. The internal circuits of
the ER-130 have been directly derived from the ARREL Audio professional units in order
to obtain maximum sonic performances.
The unit has been designed to comply with the demands of professional musicians.
MID/SIDE processing is based on the coding of a stereo signal into two components. The
“MID” channel contains the information that appears in both the left and right channels,
and the “SIDE" channel contains all the information that differs between the left and right
channels.
Once encoded into M/S, these two signals can be “creatively” processed independently,
before being decoded back into L and R channels. The M/S technique gives control over
the width of the stereo image. The ER-130 is a code/decode /stereo system to be used
primarily for Eurorack synths in live and recording applications.
On top of its amazing sound quality, the ER-130 MS unit features a unique set of functions.
1. Manual and CV (Control Voltage mode) switch
2. Control Voltage range [0V, +5V]) but it can accept up 0 +10 V (sensitivity
potentiometer)
3. High quality MID-SIDE Matrix
4. Unbalanced in/out
5. True by-pass push-button
6. Stereo width (Side) control with zero detent
7. LO-CUT filter on the SIDE channel with on/off push button
8. Insert on MID and Insert on SIDE (on/off switch)
9. Multicolor stereo depth display
10.Peak indicator (audio out signal)
Housing
The ER-130 is contained in a 10 HP Eurorack units and by a depth of about 40 mm. No
specific air conditioning is required for the unit, provided that there is a free flow of air
through the rack from front to back and the temperature is maintained in the operating
range. Consequently the racks may be stacked.

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 6
ER-130 Front Panel Controls and Operations
MODE SWITCH
Selects manual control of the stereo width or CV mode. In CV mode the control voltage in
applied on the corresponding jack. The voltage range can be 0-10 V. The potentiometer
below CV jack controls the depth of the action of the CV (Fig.1).
INPUT L/R CONNECTORS
3.5 mm connectors for the input signal (Fig.1).
OUTPUT L/R CONNECTORS
3.5 mm connectors for the output signal (Fig. 1).
CONTROL VOLTAGE (C.V.) CONNECTOR
3.5 mm connector for the Control Voltage (CV). Typical range of [0-5V] but up to +10 V can
be applied (Control volt attenuation potentiometer see below). The control voltage will
change the side gain in the range defined by the stereo width potentiometer.
NORMAL SET-UP:
1. stereo width potentiometer at maximum (completely turned clockwise)
2. C.V. attenuation potentiometer at 100% (completely turned clockwise)
With this set-up the input C.V. to obtain the maximum side gain is +5 V.
If you need to accommodate a maximum C.V of 10 V the C.V. attenuation
potentiometer must be positioned at 50 %.
CONTROL VOLTAGE (C.V.) ATTENUATION POTENTIOMETER
This potentiometer controls the depth of the control voltage action.
ON SWITCH
Push to activate the MID SIDE (LED ON).
PEAK LED
Peak led on indicate near saturation of one of the R/L out signals, it starts to work at -3 dB
of the maximum out level.
STEREO WIDTH DISPLAY
Display indicating the depth of the stereo image. Mono led on means a mono image.
Stereo led ON means a stereo image. Other leds indicate less than stereo and more than
stereo.
MID AND SIDE INSERTS
3.5 mm jacks for the unbalanced send and return on the MID and SIDE channels, the
inserts can be switched on and off by using the switches below the insert section.

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 7
STEREO WIDTH CONTROL KNOB
Manual control for the stereo width (zero central detent).
LO-CUT PUSH BUTTON
ON –OFF control for the LO-CUT filter on the MID channel, pressed switch meand that the
low cut filter is on.
LO-CUT CUT OFF FREQUENCY KNOB
Cut off frequency control for the LO-CUT filter.

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 8
APPENDIX A: Front Panel
FIG. 1 ER-130 Front Panel

ARREL Audio
ER-130 User Manual, Issue 0.1 Page 9
TECHNICAL SPECIFICATIONS
Number of Channels
Stereo
Power Supply
From the Eurorack power supply unit
Operating Voltage
+/- 12 VDC
Power Consumption
3.5 W
Input
Electronically unbalanced, Level 0 dBu max +20 dBu
Impedance 10 KΩ
Output
Stereo, Unbalanced,
Output Impedance optimum load impedance ≥ 600 ohm )
Bandwidth
5 – 60.000 Hz -1dB, perfect square wave up to 20 KHz
Distortion + Noise
<0.005% ( typical 0.001 %)
Control Voltage (C.V.)
[0, +5V] Can accept up to +12 V (Attenuation
potentiometer) 10 Kohm impedance.
Front Panel Controls:
By-pass button
Stereo width
LO-CUT on off button
LO-CUT cut off frequency knob
Stereo width control knob
Control switch
CV modulation depth control
Front Panel Indicators
BY-PASS LED
PEAK LED
STEREO WIDTH DISPLAY
Front Panel Connnectors
2 x 3.5 mm jack for the stereo input ,
2 x 3.5 mm jack for the stereo output
2 x 3.5 mm jack for the MID insert
2 x 3.5 mm jack for the SIDE insert
1 x 3.5 mm jack for the CV INPUT
Rear Panel Power Supply
Connectors
Eurorack power supply connector
Construction
10 HP
Dimensions
142 mm x 128 mm (w x h)
Weight
500 g