Alesis 12R manual Using the meter, Output distortion

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Operating Instructions

Using the meter

The meter of the Multimix 12R is a fast peak type that reads in decibels, normally displaying the level of the [MAIN OUT] jacks. When the meter reads "0", the main outputs are at the nominal level: the phono jacks at -10 dBV (.316 volts) and the 1/4" jacks at +4 dBu (1.24 volts) balanced, or -2 dBu unbalanced.

Use this reference level to calibrate your system. The input controls of analog recorders should be set so that “0” on the mixer's meters equals “0 VU” on the recorder's meters. Digital recorders use a different reference; for example, an ADAT connected to the Multimix 12R's outputs will read "-15 dB" at nominal output, if you connect to the proper input jacks (balanced to balanced, or unbalanced to unbalanced).

The meter follows the [MSTR/TAPE] switch, but not the PHONES/MONITOR level control. Whatever you hear in the headphone output, the master output (up position) or the 2-track tape input (down position) is what the meter is reading.

Output distortion

The Multimix 12R has plenty of headroom, but eventually every electronic device reaches its limit. At +18 dB over nominal level, the top LED of the meter labeled PK will light; at this point there is 6 dB of headroom before the master electronics will clip. Final clipping is reached at 24 dB over nominal "0" on the meter; this represents a level of +28 dBu at the MAIN OUT jacks if balanced, +22 dBu if unbalanced, and +14 dBV at the MAIN OUT -10 dBV phono jacks. Even if no channel PEAK LEDs are on, with extreme settings of the faders it may be possible to overdrive the output to this level.

As long as the meter of the Multimix 12R is below its top LED, and the PEAK LEDs of all channels are off, the mixer should not be causing distortion. If you hear distortion, check other devices in the signal chain for overload, and make sure the STEREO channels' PEAK LEDs do not come on when their TRIM is set to 12 o'clock.

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Contents Reference Manual Page Important Safety Instructions Page Page Page Page Page CE Declaration Of Conformity Front Panel Table of Contents Dimensional Drawing ApplicationsAlesis Multimix 12R Microphone Preamplifier/Mixer Using this manualIntroduction ConventionsGrounding Instructions Installation AC powerUnpacking Use clean power Power switchMounting Connections InputsCable common sense Microphone Inputs Phantom power Line-level devices synthesizers, CD players, video Phantom Power will not be Used Tape in jacks Phonograph turntables How to connect effect devices and signal processors Effects via Aux Send and Aux ReturnAbout stereo effect devices Using Aux 1 as an effects send Connecting an in-line processor Connections To a mono system OutputsTo a stereo PA system or instrument amplifier To a stage monitor foldback systemTo another mixer To a stereo tape recorderTo an Adat multitrack recorder In-line Adat recordingUsing two Multimix 12Rs for more flexibility Connections Phones Monitor OutConnections Operating Instructions Before turning the mixer on, zero out the controlsSetting input trim levels Peak LED methodMetering/Unity Gain method Trim gain ranges Typical Fader and Control LevelsUnity gain points Aux Send levelsProper gain staging of other equipment How to Set Aux Send and Return Levels AUX System Effects Send/ReceivePage Using the meter Output distortionAvoiding noise System noise ground loops, hum, induced noise① to Eliminate HUM if the Above has Failed Page Operating Instructions Applications Multitrack recordingTracking/Overdubbing Mixdown Using the High and LOW EQ controls Monitoring AUX 1 in the Phones jack Troubleshooting Troubleshooting IndexPage Maintenance/Service Exterior cleaningRefer All Servicing to Qualified Technicians Specifications ConnectorsFrequency Response Levels ImpedancePower Noise performance typicalDistortion THD+N Dimensional Drawing Block Diagram Level diagram Index TapeWarranty / Contact Alesis Contact Information