User manual PRESONUS BLUETUBEDP

[. . . ] In no event will PreSonus be liable for incidental, consequential or other damages resulting from the breach of any express or implied warranty, including, among other things, damage to property, damage based on inconvenience or on loss of use of the product, and, to the extent permitted by law, damages for personal injury. Some states do not allow the exclusion of limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific legal rights, and you may also have other rights, which vary from state to state. This warranty only applies to products sold and used in the United States of America. [. . . ] The polarity reversal switch also can compensate for different XLR connector hookups where pin connections have been inverted. A -20dB 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 incoming signal and a much reduced chance of overdriving the input and thereby avoiding distortion. This lets you greatly reduce background noise such as air conditioners or wind noise with the flick of a switch without effecting the desired frequencies. XLR / ¼ inch connector is provided on the back of the chassis for signal input from microphone XLR or instrument ¼ inch ? ? ? ? 5 input. ? Tube Drive. The BLUETUBE DP provides a Tube Drive potentiometer on each channel for controlling the amount of saturation produced by the 12AX7 vacuum tube. Greater levels of tube saturation give the signal greater warmth and a richer sound. This works equally well on mics and instruments. 6 2. 1 FRONT PANEL BASIC LAYOUT The front panel of the BLUETUBE DP has analog VU meters for channel 1 and 2 to the far left and far right respectively, which measure the input level. VU stands for ` volume unit' which is an average measurement of , the input signal level. ? +48V Switch Polarity Reversal Switch -20dB Pad 80Hz Filter Gain Control (0 to 54dB) Tube Drive Control (0 to100%) 2. 2 PREAMPLIFIER SECT I O N 7 Phantom Power is available to each channel input of the BLUETUBE DP. 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 Polarity Reversal Switch. This 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' XLR connector be switched to s successfully utilize Phantom power. -20dB Pad. This is a very useful feature for rapidly reducing the level coming into the BLUETUBE DP and thus preventing the input signal from overmodulating (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. Gain. This control governs the amount of boost to the signal being processed by the preamplifier. Dynamic mics and instruments without pre-amps will normally require more gain than condenser mics and instruments that have a built-in preamp (care should be taken with instruments having their own built-in preamp not to overdrive the input of the BLUETUBE DP). If you should require more signal out of the pre- amp for a hotter recording level or to drive an input of some down stream device harder, cranking up the gain should provide all the 8 signal that you' need. [. . . ] Care should be taken not to overdrive the input with instrument preamplifiers. 11 3. 4 SOME THOUGHTS ON VACUUM TUBES The BLUETUBE DP comes supplied with a 12AX7 vacuum tube that meets or exceeds the stated performance criteria for the unit. We expect some owners of the BLUETUBE DP will try different tubes to investigate the various performance possibilities they might provide. Tube replacement can be easily accomplished by first unplugging the unit from the electrical outlet and removing the screws which attach the top to the chassis. 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. [. . . ]