PreSonus Studio Channel - Manual (Page 8)

CONTROLS AND CONNECTIONS
6 | PreSonus 2007
2.1 FRONT PANEL LAYOUT
2.1.1 Tube Microphone Preamp
 Instrument Input. The ¼” TS connector on the front panel is for use with a passive instrument (guitar,
bass, etc.). When an instrument is plugged into the instrument input, the microphone preamp is
bypassed, and the Studio Channel 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 Studio Channel not only risks damage to these
inputs but also results in a very loud and often distorted audio signal.
(In other words, don’t plug a line level source into the front panel jack)
 Input Gain/Trim Control. These knobs provide the following gain structure:
o
XLR Microphone and TS Instrument/Hi-Z Inputs. 44 dB of variable gain (+10 dB to +54 dB)
 Tube Drive. The Tube Drive control increases the amount of signal routed through the 12AX7 vacuum
tube. (The gain controls overall volume, whereas the drive controls volume routed through the tube.)
The effect achieved ranges from subtle to extreme, depending on the setting being used:
o
“Warming Up the Sound”. This effect is achieved by adding in a small amount of Tube Drive
(30% or less). It is especially desirable for vocals and electric bass. The resulting sound is
richer and sweeter.
o
“Overdriven Tube Sound”. This effect is achieved by adding in 30-100% of Tube Drive. The
more Tube Drive you add, the more overdriven the sound will be. This sound is extremely
useful in creating distorted guitar and that authentic “blues harp” harmonica sound.
 48 Volt Phantom Power. This button enables phantom power to the XLR input.
XLR connector wiring for Phantom Power
Pin 1 = GND
Pin 2 = +48V
Pin 3 = +48V