Manley LANGEVIN DUAL Owner's Manual

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Manley LANGEVIN DUAL Owner's Manual Manual pdf 6 page image

CONNECTING YOUR PREAMPLIFIER6Easy - Connect the mic to the Microphone Input XLR, then connect the Line Output to yourtape machine or console. Read on, there are some things to consider.On the back panel are female XLR's labelled MIC INPUT A and MIC INPUT B. The signalfrom the MICROPHONES get plugged in here. Here are a few warnings and suggestions.These XLR connectors also "send" PHANTOM POWER to the mics. Some mics can bedamaged by the 48 volts of phantom power. A few PZMs and a few ribbon mics have beenknown to "fry" when fed phantom power. The suggestion is to ALWAYS have PHANTOMswitched off when switching mics, cables, patches that involve mics etc. You ONLY usephantom power for PRO SOLID STATE "FET' CONDENSOR MICS. Tube mics, dynamicmics, ribbon mics and battery powered mics should have phantom switched "off". This istrue for all mic pre's. With this MIC PRE you "PULL THE TOGGLE to SWITCH PHAN-TOM". It is a locking toggle to prevent "accidents". The second great reason for not usingphantom if you don't have to is that - if you change a connection with phantom on, then thepre amp will be fed a quick burst of 48 volts (when it normally is amplifying about a hun-dredth of a volt), which can then be monitored - usually once. After you have replaced yourspeakers, you have learned a valuable lesson about turning down the volume of the monitorsbefore changing mics or mic patches. This is a good idea with phantom on or off. Consider avariation of this - any mic connection just a little bit bad,will be extra noisy with phantomturned on. This goes for cables, patchbays, patch cords etc. Suggestion #2 - Avoid runningmic signals through patchbays. Some patchbays "ground" all the "sleeves" which can add aground loop into your delicate mic signal. Suggestion #3 - Set up the Mic Pre in the studionear the mic and use a short mic cable. Why ? Microphones often have "light duty" linedrivers and you can lose an audible amount of signal in long cables. You can get the bestfidelity by having the Mic Pre close to the mic at the "cost" of having to walk into the studioto adjust a level control. You also avoid almost all of that phantom power / patching problembecause now you are patching a regular line level signal only.TheMIC INPUT XLR PIN OUT is :PIN 1 = CIRCUIT GROUNDPIN 2 = HOT or positive going phasePIN 3 = LOW or negative going phaseThe LINE OUTPUT XLR PIN OUT is:PIN 1 = CIRCUIT GROUNDPIN 2 = HOT or positive going phasePIN 3 = LOW or negative going phaseThis is a simple balanced output. It will feed balanced inputs but not unbalancedinputs "correctly". When it is plugged into an unbalanced input, expect a 6 dB loss of outputlevel. This will occur no matter how you wire the cable. The best way to drive an unbalancedinput with this unit is not to connect to PIN 3 at the output XLR - just use PIN 1 (ground) andPIN 2 (signal). Better to have PIN 3's signal float than short. You may not notice the 6 dB"loss" because the preamp still has good headroom.