User manual ART TUBEFIRE 8

[. . . ] TubeFire 8TM 8 CHANNEL TUBE MIC-PREAMP SYSTEM USER'S GUIDE IMPORTANT SAFETY INSTRUCTIONS ­ READ FIRST This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosure. Voltage that may be sufficient to constitute a risk of shock. This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. Please read manual. Read instructions: Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the equipment. [. . . ] One way to determine how this switch should be set is to send audio through the TubeFire 8TM from a computer and run it into a line input on a mixer or signal processor. Check the meters on the mixer or signal processor to see if the level appears to be too high (clipping) or too low (barely showing any indication on the meters). Set the Output Level switch so that the level meters in the external gear do not indicate excessive clipping yet still provide good full-scale (or near full scale) deflection. FIGURE 3 - Rear Panel Wordclock Input and Thru Jacks The Wordclock input is used to externally sync the TubeFire 8TM to a master clock source. The BNC Wordclock Input jack is connected directly to the BNC Wordclock Thru jack, providing the ability to loop through the TubeFire 8TM and connect other devices to the wordclock sync source, saving the use of a BNC T­ adapter. The input is high impedance thus leaving the wordclock connection unterminated. (A 75 Ohm BNC terminator should be used on the Wordclock Thru jack if the Wordclock Input jack is used only by itself. ) Firewire Jacks The Firewire jacks are interchangable and allow both connection to your computer and to other Firewire devices including additional TubeFire 8TM units. 8 HARDWARE OPERATION How to adjust the controls for the lowest noise Start with the GAIN and OUTPUT knobs centered, and the Pad switch IN. Increase the Gain control until the Clip LED in the meter just barely comes on during the loudest peaks in level, and then back off the control slightly from that point. (The Clip LED can come on occasionally at most. ) If there is not enough level with the Gain control set fully clockwise, back off the gain to 12 o'clock and place the Pad switch in the out position. Adjust the Output control until the -10 light is on most of the time during loud passages. Increasing the input gain and decreasing the Output level control can add more tube warmth. Remember, that the Clip LED looks at both the preamp input and output peaks, whereas the -10, -20, -30 LED indicators only look at the output level which feeds to the A/D converter. How to set the Output Level switch (on the rear panel) Setting this switch correctly can lower the noise in the signal chain by optimizing the operating levels between the TubeFire 8TM and external gear. One way to determine how this switch should be set is to send audio through the TubeFire 8TM from a computer and run it into a line input on a mixer or signal processor. Check the meters on the mixer or signal processor to see if the level appears to be too high (clipping) or too low (barely showing any indication on the meters). Set the Output Level switch so that the level meters in the external gear do not indicate excessive clipping yet still provide good full-scale (or near full scale) deflection. How to use the Headphone / Line Mixer Output The TubeFire 8TM has eight D/A outputs that return audio from the computer and are assignable to the headphone output through the Output Source switches. This is done in pairs to support stereo operation. When a switch is in the OUT position, the corresponding channel pair of D/A's (audio from computer) is selected to be mixed into the headphone output. When depressed, the corresponding channel pair of analog tube preamp outputs is mixed into the headphone output. First, determine which D/A's to use as a source from the computer. A good start would be to use channels 7 & 8, since channels 1 & 2 are the most flexible for use as inputs. 7 - 8 Output Source switches are in the OUT position. Next, decide which inputs you wish to monitor, and depress these switches. You can turn down the Output level controls on the unused channels. [. . . ] A R T shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary, from state to state. For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service. 21 SERVICE The following information is provided in the unlikely event that your unit requires service. [. . . ]