21. Signaling specified by base-3 conversion with direct mapping of base-3 digits to line levels ( 8B6T code ). 22. Most models now offered include a preamp with a line level output as well as a USB output. 23. The Sonic Six also features a built in amplifier and speaker, as well as a standard line level output. 24. NOTE : Drawing captioned " USING A LINE LEVEL FOR PUTTING UP FENCE POSTS " goes with this column. 25. The nominal level and the reference voltage against which it is expressed depend on the line level being used. 26. A line level describes a line's nominal signal level as a ratio, expressed in decibels, against a standard reference voltage. 27. Depending on local practices these amplifiers will usually amplify the audio signals to 50V, 70V or 100V speaker line level . 28. During the first two months of renovations, two additional Scollay Under tile signs were uncovered on the Blue Line level . 29. This is a line level input that can accept the output from a DVD player with 5.1 discrete channel outputs. 30. Conversely, microphone and line level audio cables lack the requisite electrical characteristics and thus are not suitable for DMX512 cabling.