background image

    

Phantom Power

 

is available to each channel input of the 

Blue 

Tube.  

The

 48 volts

 is supplied by way of the XLR connector for 

condenser mics and any other devices requiring continuous power 
through the XLR input.  This power is supplied at a constant level 
allowing use of both inputs simultaneously.

 

 

 

PIN 1 GND 

PIN 2  +48v 

PIN 3 +48v 

XLR 

connector wiring for 

Phantom Power

 

Phase Reverse Switch

 

allows the user to invert the polarity of the 

XLR connector by switching pins two and three.  The inversion of the 
pins of the XLR connector may be necessary to alter the audio 
phase of two like microphones to compensate for phase 
cancellation.  It may be required that the wiring of a cable’s XLR 
connector be switched to successfully utilize Phantom power. 

 

-20 dB Pad

 

provides -20 decibels of attenuation with the push of a 

button.  This is a very useful feature for rapidly reducing the level 
coming into the MP20 and thus preventing the input signal from 
over-modulating (distorting) the input.  This may occur due to high 
output level from a microphone or line device.  Padding the input 
serves to provide increased “headroom” for the operator. 

        

Drive.

  

The Blue Tube Drive control increases the amount of signal 

routed through the 12AX7 vacuum tube.  The effect achieved by this 
procedure can be subtle to extreme, depending on the setting being 
used.  A “warming up” of the sound can be noticed at lower 

Summary of Contents for Blue Tube

Page 1: ...BlueTube TwoChannelMicrophone Instrument TubePreamplifier User s Manual...

Page 2: ...Blue Tube T W O C H A N N E L M I C R O P H O N E I N S T R U M E N T T U B E P R E A M P L I F I E R USERS MANUAL Version1 0 2000 PreSonus Audio Electronics Incorporated All rights reserved...

Page 3: ...cover claims for damage due to abuse neglect alteration or attempted repair by unauthorized personnel and is limited to failures arising during normal use that are due to defects in material or workm...

Page 4: ...ont Panel Basic Layout 7 2 2 Preamplifier Section 9 2 3 Back Panel Basic Layout 11 3 Operation 3 1 Dynamic Microphones 14 3 2 Phantom Powered Microphones 14 3 3 Instrument Input 14 3 4 Some Thoughts o...

Page 5: ...ask is by listening to the experts on our gear our valued customers We appreciate the support you have shown us through the purchase of this product Please pay close attention to how you connect your...

Page 6: ...tch enables the user to invert the phase of a microphone if phase cancellation is noticed when using identical microphones in close proximity to one another The phase reverse switch also can compensat...

Page 7: ...tentiometer on each channel for controlling the amount of signal routed to the 12AX7 vacuum tube This feature lets you control how much saturation of the signal occurs Greater levels of tube saturatio...

Page 8: ...r from left to center and from right to center Identical preamplifier sections Channel One left to right and Channel Two right to left comprise the front panel Both preamp channels contain Combination...

Page 9: ...hones to compensate for phase cancellation It may be required that the wiring of a cable s XLR connector be switched to successfully utilize Phantom power 20 dB Pad provides 20 decibels of attenuation...

Page 10: ...ve control are up to you your application and your imagination Experiment Gain This control governs the amount of boost to the signal being processed by the pre amplifier Dynamic mics and instruments...

Page 11: ...igh PIN 3 Low Cable Wiring Diagram for Input and Output XLR The Output XLR Connector is servo balanced and operates at 4dBu TIP High SLEEVE GND Cable Wiring Diagram for Input and Output Phone Plug The...

Page 12: ...denser and some ribbon microphones require external power to pre amplify the microphone acoustic pickup These microphones typically have much higher output than dynamic microphones Hence the 20dB pad...

Page 13: ...nsverse fashion and care should be taken to properly align the pins on the tube to the corresponding holes in the receptacle Make sure the tube is completely seated in the receptacle and replace the t...

Page 14: ...ounting of the Blue Tube to the left of the Blue Max will minimize any field effect the magnetism that the Blue Max s transformer may have It should be noted that proximity to computer CPU s power sup...

Page 15: ...d 51 Ohms Output Impedance TRS Unbalanced 51 Ohms Panel Controls Tube Drive 0dB to 30dB Gain 0dB to 40dB Phase Reversal 20dB Pad 48V Phantom Power Metering 8 Segment LED 28dBu to 18dBu Power Supply Ty...

Page 16: ......

Reviews: