Mackie 1402-VLZ Pro Owner's Manual - Page 11

LINE INPUTS (Channels 1-6) These six line inputs share circuitry (but not phantom power) with the mic preamps, and can be driven by balanced or unbalanced sources at almost any level. You can use these inputs for virtually any signal you'll come across, from instrument levels as low as -40dB to operating levels of -10dBV to +4dBu, since there is 40dB more gain available than on Channels 7-14. To learn how signals are routed from these inputs: . To connect balanced lines to these inputs, use a 1⁄4" Tip-Ring-Sleeve (TRS) plug, the type found on stereo headphones: RING SLEEVE SLEEVE RING TIP TIP RING TIP SLEEVE Tip = Positive (+ or hot) Ring = Negative (- or cold) Sleeve = Shield or ground To connect unbalanced lines to these inputs, use a 1⁄4" mono (TS) phone plug or standard instrument cable: SLEEVE SLEEVE TIP TIP TIP SLEEVE Tip = Signal Sleeve = Ground Line inputs 1-6 are a good place to connect older instruments that need more gain. You can correct weak levels by adjusting the corresponding channel's TRIM control . LOW CUT (Channels 1-6) The LOW CUT switch, often referred to as a High Pass Filter (all depends on how you look at it), cuts bass frequencies below 75Hz at a rate of 18dB per octave. +15 We recommend +10 that you use LOW +5 CUT on every micro- 0 phone application -5 except kick drum, -10 -15 bass guitar, bassy 20Hz 100Hz Low Cut 1kHz 10kHz 20kHz synth patches, or re- cordings of earthquakes. These aside, there isn't much down there that you want to hear, and filtering it out makes the low stuff you do want much more crisp and tasty. Not only that, but LOW CUT can help reduce the possibility of feed- back in live situations and it helps to conserve the amplifier power. Another way to consider LOW CUT's func- tion is that it actually adds flexibility during live performances. With the addition of LOW CUT, you can safely use LOW equalization on vocals . Many times, bass shelving EQ can really benefit voices. Trouble is, adding LOW EQ also boosts stage rumble, mic handling clunks and +15 breath pops. LOW CUT re- +10 +5 moves all those problems so 0 you can add low EQ without -5 losing a woofer. -10 Here's what the combina- -15 20Hz 100Hz 1kHz 10kHz 20kHz tion of LOW EQ and LOW Low Cut with Low EQ CUT looks like in terms of frequency curves. TRIM (Channels 1-6) If you haven't already, please read the Level Setting Procedure . TRIM adjusts the input sensitivity of the mic and line inputs connected to Channels 1 through 6. This allows signals from the outside world to be adjusted to optimal internal operating levels. If the signal originates through the XLR jack, there will be 0dB of gain with the knob fully down, ramping to 60dB of gain fully up. Through the 1⁄4" input, there is 15dB of attenuation fully down and 45dB of gain fully up, with a "U" (unity gain) mark at 10:00. This 15dB of attenuation can be very handy when you are inserting a signal that is very hot, or when you want to add a lot of EQ gain, or both. Without this "virtual pad," a scenario like that might lead to channel clipping. +4 / -10 (Channels 7-14) This switch adjusts the input sensitivity of the line inputs on channels 7-14. If the sound source is a "-10" device, engage this switch. If you are unsure, leave the switch up and perform the Level Setting Procedure , substituting this switch for the TRIM knob and then setting the switch to the appropriate gain setting. 11