PreSonus FireStudio - Manual (Page 39)

CONTROLS AND CONNECTIONS
36 | PreSonus 2008
3.2 FRONT PANEL LAYOUT
 Microphone Preamplifier. Your FireStudio is equipped with eight custom designed PreSonus XMAX
microphone preamplifiers for use with all types of microphones (including dynamics, condensers, and
ribbons). As well as instruments and line-level signals. The PreSonus preamplifier design employs a
Class A input gain stage. This arrangement results in ultra-low noise and wide gain control, allowing
you to boost desirable signal without increasing unwanted background noise.
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48-Volt Phantom Power. The FireStudio has 48V phantom power available in two groups via
button switches on the front panel. The top button activates phantom power for channels 1-4.
The bottom button activates phantom power for channels 5-8.
 XLR-connector wiring for phantom power:
 Pin 1 = Ground
 Pin 2 = +48V
 Pin 3 = +48V
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+14 dBu Headroom. The FireStudio microphone preamplifier has +14 dBu headroom. This
feature gives you wide dynamic range and excellent transient-response characteristics.
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Combo Connectors. Each channel of the FireStudio has a Combo mic/line connector. This
connector lets you use either female ¼” phone or XLR connectors in the same jack. The ¼”
inputs on channels 3-8 are line-level inputs. When these inputs are engaged, the microphone-
preamp circuit is bypassed.
 Instrument Inputs (Channels 1 and 2). The ¼” TS connector on Channels 1 and 2 are for use with an
instrument (guitar, bass, etc.). When an instrument is plugged into the ¼” input, a high impedance
input buffer is switched into the preamp circuit and the FireStudio becomes an active instrument
preamplifier.
NOTE: Active instruments are those that have an internal preamp or a line-level output . Active
instruments should be plugged into a line input rather than into an instrument input. Plugging a line-
level source into the instrument inputs on the front of the FireStudio not only risks damage to these
inputs but also results in a very loud and often distorted audio signal. Therefore, don’t plug a line-level
source into the combo jacks of channels 1 or 2.
These two channels also feature a send and return on the back panel of the FireStudio. The return
inputs can be used as line-level inputs for these two channels if instrument preamps are not needed.