The Rear Panel; Something To Consider: Ground Loops - Arturia KEYLAB mkII User Manual

1.4. The Rear Panel

Pitch/Gate/Mod outputs These four connectors allow the KeyLab mkII to send
1.
control voltages and triggers to a modular synthesis system. The voltage ranges
may be defined in
[p.61].
MIDI In / Out KeyLab mkII's MIDI Out connector will send USB / MIDI data
2.
to external devices, and can do so without a computer when powered with the
optional power supply. The MIDI In connector receives MIDI data from external
devices, and also serves as a MIDI / USB converter for your DAW.
Aux 1/2/3 Pedal Inputs These three pedal inputs can be used with a continuously
3.
variable pedal or a footswitch. They can be assigned to any MIDI CC number
from within the KeyLab mkII [p.42]
Expression Pedal Input The Expression pedal input can be used with a
4.
continuously variable pedal or a footswitch. It sends MIDI CC# 11 by default, but
it can be reassigned from
Control Center
Sustain Pedal Input The Sustain pedal input automatically detects the polarity of
5.
the pedal when KeyLab mkII is turned on, so it can be used with any standard
pedal. It also can be configured to work as a continuously variable pedal
the front panel of the KeyLab mkII [p.42]
[p.61].
CV In Use this connector to route a control voltage output from a modular
6.
synthesizer into the KeyLab mkII. This input can be used as a CV-to-MIDI
converter and/or a CV-to-USB converter. The voltage range may be defined from
the front panel or using the
USB Connection Use this to connect KeyLab mkII to your computer. This port
7.
provides both power, MIDI data, and control information.
Power connector If you'd like to use KeyLab mkII as a controller without a
8.
computer attached, connect an optional 9-12v DC 1.0A power supply here.
Power switch This on/off switch works the same whether the unit is powered by
9.
USB or by the AC adapter: up is on, down is off.

1.4.1. Something to consider: Ground loops

A ground loop is an unwanted current in a conductor connecting two points. The result
is noise in your audio signal, usually in the form of a low-frequency hum. In setups
involving computers, CV/Gate connections, and audio devices, it's possible to end up with an
annoying ground loop. We have provided a solution, however: the anti ground loop adapter.
1.4.1.1. When should I use the anti ground loop adapter?
In most cases you will not need the anti ground loop adapter.
If you don't have a ground loop problem in your setup, simply connect the KeyLab mkII
with the supplied USB cable to a computer or with an optional 9-12v DC 1.0A power supply.
7
User Edit mode [p.44]
or by using the
within the KeyLab mkII [p.42]
[p.61].
MIDI Control Center
or by using the
MIDI Control Center
or by using the
[p.61].
Arturia - User Manual KeyLab MkII - Getting Started
MIDI Control Center
[p.61].
or by using the MIDI
from
MIDI Control Center