7
Front Panel Controls & Indicators
Preamp Circuit
Gain Control
The Gain control sets the amount of input gain of the Tube Channel.
Turn the control clockwise to increase gain and counterclockwise to
decrease gain. Selection of the gain range is made with the +20dB
gain switch. You may control two ranges of gain with this control, +9
to +50dB and -11 to +30dB. When setting the Gain control, refer to
the 4 segment Tube Drive Array for a visual reference to the Tube
Channel’s internal signal levels (applied gain). Hint: the “sweet spot”
for the Tube Channel is when the second” warm” Light Emitting
Diode (LED) in the Tube Drive array is lit.
Gain Switch
Use the Gain switch to set the range of the Gain control. When the
switch is in the out (0db) position the gain range is -11 to +30dB.
Depressing the switch adds 20dB of gain. With the switch in, the gain
range is +9 to +50dB. Note: With most microphone applications
you’ll find using the Tube Channel with the +20dB gain switch in is
needed. Use the setting that best fits your application.
Phantom Power Switch
The Tube Channel can power any microphone n48 volts DC
phantom power. Consult your microphone’s documentation to see if
phantom power is required to power it. Phantom power is turned on
and off with this switch and supplies power to pins 2 and 3 of the XLR
input jack.
Note: It is best to have phantom power turned off when connecting