User manual PRESONUS BLUETUBE

[. . . ] PreSonus reserves the right to change or improve the design of the product at any time without prior notice. This warranty does not 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 workmanship in the product. Any implied warranties, including implied warranties of merchantability and fitness for a particular purpose, are limited in duration to the length of this limited warranty. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you. [. . . ] This assures optimum performance of your condenser microphone(s) and that the signal will be free of distortion due to insufficient power. A phase reverse switch is provided on each channel. This switch 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 compensate for different XLR connector hook-ups where pin connections have been inverted. A 20 dB pad is available on each channel for reducing the in-coming signal level. This pad provides a more manageable signal from high output devices giving the operator greater control over the in-coming signal and a much reduced chance of over-driving the input and thereby avoiding distortion. · · · Mic/Instrument Input. Each channel of the BlueTube has a separate Neutrik Combo© XLR / ¼ inch connector is provided on the front of the Blue Tube for signal input from mic XLR or instrument ¼ inch input. · Drive. The Blue Tube provides a Drive potentiometer 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 saturation give the signal greater warmth and a richer sound. This works equally well on mics and instruments. 2. 1 FRONT PANEL BASIC LAYOUT Notice that the front panel of the Blue Tube is divided evenly at the +48V switch in the center of the unit. The input and controls are a mirror image of each other 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 Microphone (XLR) and Instrument (1/4 inch) input Phase Reverse Switch Drive Control (0 to 30dB) · · -20db Pad Gain Control (0 to 40dB) A single +48 volt phantom power switch is used for both channels. · Phantom Power Switch 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 tube is mounted in a transverse 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 top of the unit before restoring power to it. Remember: Tube life and performance are affected by how often a tube is used and by how hard the tube is driven when in use. Signs of wear may be exhibited by poor performance or by the tube becoming "microphonic". [. . . ]