User`s manual

CONTROLS & CONNECTIONS
29 | PreSonus 2008
• Instrument Inputs (Channels 15 and 16). The ¼” TS connector on channels 15 and 16 are for use with
an instrument (guitar, bass, etc.). When an instrument is plugged into the instrument input, the
microphone preamp is bypassed, and the FireStudio Tube 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 Tube 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 combo jacks of channel 15 or 16.)
• LED Meters
. Each SuperChannel features two 6-LED level indicators. The indicator on the left meters
the input signal. The meter on the right meters the amount of gain reduction through the limiter
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VU indicator. The VU indicator meters the input signal. The first three green LEDs will light
up when your input signal from either the XLR (Mic) or ¼” (Instrument) reaches -40dBfs,
-20dBfs, and -12dBfs respectively. The two yellow LEDs will light up when the channel’s input
signal reaches -6dBfs and -3dBfs respectively. The red clip indicator LED will illuminate when
the channel’s input signal reaches 0dBFS. At this level, your Mic/Instrument trim signal will
exhibit signs of clipping such as distortion. It is highly recommended you do not allow your
converters to clip (the red clip indicators to light up) as the sound quality will not be desirable.
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Gain Reduction indicator. This meter shows the amount of gain reduction implemented by the
limiter. As you turn the Limiter knob to the right, the amount of input gain being reduced will
lessen.
• 80Hz Rumble Filter.
A rumble filter is available to eliminate low frequency noise. This lets you greatly
reduce background noise from things such as air conditioners or wind noise with the flick of a switch
without affecting the desired frequencies. The button will illuminate when the 80Hz filter is engage.
• Limiter
. This button is used to engage the Limiter. The button will illuminate when the limiter is
engaged.