User Manual

3
2 Hookup
2.1 Front Panel Connections and Controls
Quantum-series
Owner’s Manual
2 Hookup
2.1 Front Panel Connections and Controls
Microphone inputs. Your Quantum-series interface is equipped with 8/4 digitally
controlled PreSonus XMAX microphone preamplifiers for use with all types of
microphones. The XMAX design provides a Class A input buffer, followed by a
dual-servo gain stage. This arrangement results in ultra-low noise and wide gain
control, allowing you to boost signals without increasing noise. The ¼-inch front
panel inputs on Quantum can be either line or instrument. By default, they are set to
line. These inputs are not switching on the Quantum 2.
Each analog input on the Quantum-series interface features a combo jack. This
convenient connector accepts either a ¼-inch phone plug or an XLR plug. Mic Inputs
3-8/4 are located on the rear of the unit. Each input on your Quantum-series interface
is also auto-sensing. When an XLR is connected, the signal is routed to the preamp.
When a TRS is connected, the preamp is bypassed and the input signal is sent directly
to the ADC. When nothing is connected, Channels 1 and 2 on Quantum will default
to line inputs, Channel 3-8 will default to mic. All analog inputs on the Quantum 2
default to mic.
Instrument inputs. The ¼-inch TS connectors on Channels 1 and 2 are for use with
instruments (guitar, bass, etc.). When an instrument is plugged into the instrument
input, the mic preamp is bypassed, and the signal is routed to the instrument
preamplifier stage. Quantum users must engage the Inst button to use the
Instrument inputs.
Please note: As with any audio input device, plugging in a microphone or an instrument,
or turning phantom power on or off, will create a momentary spike in the audio output of
your Quantum-series interface. Because of this, we highly recommend that you turn
down the channel trim before changing connections or turning phantom power on or
off. This simple step will add years to life of your audio equipment.
Preamp controls. These controls allow you to adjust the gain and enable phantom
power for every onboard microphone and instrument preamp.
• Preamp Gain: Use this control to adjust the level of microphone preamps
1-8/4 and instrument preamps 1 and 2. The display to the far right will show the
current trim level. This encoder is also used to change from +4dbu to -10dbv
when a line-level TRS jack is connected.
• Next / Prev: Use these buttons to select the microphone preamp you wish to
control. The display to the right of the trim control will show which preamp is
currently being controlled.
• 48V: The Quantum-series interfaces provide 48V phantom power for each
microphone preamp. This feature can be individually enabled for each channel,
using this button. When 48V is active, the blue LED at the top of that channel’s
meters will illuminate.
Warning: Phantom power is only required for condenser microphones and
can severely damage dynamic mics, especially ribbon mics. Therefore, switch
phantom power off for all channels where it is not required.
XLR connector wiring for phantom power:
Pin 1 = GND Pin 2 = +48V Pin 3 = +48V