Proel TUBE100USB - Manual (Page 11)

11
GENERAL INFORMATION
Thank you for having chosen a PROEL product .
The TUBE100USB is a first-class tool for professional microphone and instrument amplification that combines low noise
transistor technology, the warmth and hot sound of a vintage 12AX7 dual triode valve circuit, the straight-forward A/D
USB audio acquisition in almost any personal computer. The clear and simple user interface offers easy access to all
features:
• 12AX7 tube preamp section for adding warmth to microphones and instruments.
• Built-in low-noise +48V phantom power.
• PHASE reverse switch, adjustable LO-CUT filter, VOCAL EQ, built-in LIMITER circuit
• Input and output GAIN controls plus SATURATION function.
• Accurate dual LEVEL METER
• Microphone (XLR-F) and instrument (¼” JACK) inputs.
• XLR-M and ¼” JACK balanced outputs.
• USB 1.1 compliant, compatible with Windows XP/Vista/7/8 and Mac OS 9.1 and newer.
OPERATING INSTRUCTIONS (FIG. 1-4)
1. INPUT VU METER
To monitor the signal being presented to the preamp’s input, there is a six segment LED VU meter indicating –20, -10,
-6, 0, +6 dB and OL (overload). Use the INPUT VU METER when you are setting your initial input level with the INPUT
GAIN control .
2. INPUT GAIN control
The INPUT GAIN is used to set the level of the input signal . The control knob provides a range of gain from 0 to +60 dB
using the MICROPHONE input or from -10 to +50 dB using the INSTRUMENT input . Be sure to monitor the INPUT VU
METER and try to set the INPUT GAIN control so that the meter reads about 0 dB . If you see the OL LED light you are
“overloading” and the sound may become distorted. If this happens, simply back down on the INPUT GAIN control until
the OL light extinguishes.
3. LOW CUT FREQ control
This controller sets the exact frequency to start attenuating the low-end. Be sure that the LOW CUT switch is engaged.
The controller allows you to set the low-cut attenuation to any frequency between 18 and 300 Hz.
4. OUTPUT VU METER
This VU meter monitors the signal being sent from the TUBE100USB with a scale from infinity to +4 dB. Use the OUTPUT
VU METER when you are setting your output level using the OUTPUT LEVEL control. Try to set the level so that the meter
reads about -3 dB to 0 dB . If you see the pointer stay in the red area (more than 0 dB) of the OUTPUT VU METER, you are
“overloading” and the sound may become distorted . If this happens, simply back down on the OUTPUT LEVEL control
until the meter reads about 0 dB or less.
5. TUBE indicator
Indicator LED that lights when the 12AX7 internal valve is ready for operation (pre-heating of the valve filament).
6. SATURATION control
Used to adjust the total amount of even harmonic overtones and “warmth” sound generated by the tube circuit .
7. OUT LEVEL control
Used to control the output level. When the knob is fully counter-clockwise the output is off , at "0" marking indicates a
+4dBu nominal output level, with a gain of 10dB when fully rotate clockwise. It is used in combination with the OUTPUT
VU METER to set the right level while recording .
8. POWER switch
This switch turns on and off the TUBE100USB, the build-in LED lights when pressed to the “on” position.
9. 48V indicator
RED LED that indicates when the 48 V phantom power is activated.
10. 48V switch
Switch used to activate the 48 V phantom power. Most professional condenser microphones require phantom power,
which is a lower DC voltage delivered to the microphone on pin 2 and 3 of the XLR microphone connector . Dynamic
microphones do not require phantom power, however phantom power will not harm most dynamic microphones should
you plug one in while the phantom power is on. Check the manual of your microphone to find out for sure whether or
not phantom power can damage it .