PreSonus FireStudio Project - Manual (Page 33)

CONTROLS AND CONNECTIONS
30 | PreSonus 2009
 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 Project 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.
 Input Gain/Trim Control. These knobs provide the following gain structure:
o
XLR Microphone Inputs. 54 dB of variable gain (-4 dB to +50 dB)
o
TS ¼” Instrument/Hi-Z Inputs. 54 dB of variable gain (-4 dB to +50 dB)
o
TRS ¼” Line Inputs. 32 dB of variable gain (-16 dB to +16 dB trim adjustment)
 LED Meters/Clip Indicator. Each channel features three LED level indicators. The green LED will light
up when your input signal from the XLR (mic input) or ¼” (line input) reaches -40 dBFS (-30 dBu).
The yellow LED will light up when the channel’s input signal reaches -6 dBFS (+4 dBu). The red clip
indicator LED will illuminate when the channel’s input signal reaches 0 dBFS (+10 dBu). At this level,
the signal will begin to overload the converters and exhibit signs of clipping, an undesirable type of
distortion. Use the gain controls to keep the signal below 0 dBFS.
Mic Inst r ument
1 2
FIRESTUDIO ™
60+20 -20 0 60+20 -20 0 60+20 -20 0 60+20 -20 0 60+20 -20 0 60+30 -10 0 60+30 -10 0
1 2 3 4
60+20 -20 0
5 6 7 8
0dB
-6dB
-40dB
0dB
-6dB
-40dB
0dB
-6dB
-40dB
3/ 4
48V
5/ 6
48V
7/ 8
48V
1/ 2
48V
1 2 3 4 5 6 7 8