Manley Langevin Dual Vocal Combo Owner's Manual

Contents

Manley Langevin Dual Vocal Combo Owner's Manual Manual pdf 7 page image

MIC PRE BASICS7This Microphone Preamp, like most mic preamps, is pretty easy to use. First we can discuss whyoutboard mic pre's have become "a must have item" in almost every studio even though your consoleprobably has a bunch of them and that manufacturer claims that they are really great and you don't needoutboard mic pre's. Then, why is everybody buying them, using them, and why are most people going backto tubes or vintage transistor based circuits?Good question. The signal from a typical mic is very low - anywhere from 20 to 70 dB below yournormal line level signals. 95% of the time 30 to 40 dB of gain is all that is needed to boost the signal to linelevels. Where you really need a lot of gain is with most ribbon mics and when you are recording chambermusic from a distance. Mic signals are fragile and raw. The fragility is apparent when one compares variousmic pre's - each preamp seems to sound different - no EQ, no compression, nothing elaborate - just basicgain. Maybe it is the mic reacting different into different circuits. Each preamp, tube or solid state seemsto impart a flavour or color (or personality) of its own. Some of these flavours are subtle and some are not.A few engineers have an array of mic pre's and use them almost like effects - using each for a certain flavoras needed. The rest of us only have the budget for one or two great mic pre's so we tend to choose one thatsounds "best", or is priced for us, or is used by "xxxxxx". The Langevin Microphone Preamplifier is superbsounding - probably because it has a simple all discrete gain stage with a minimum of components and aminumum amount of negative feedback. Specifications, while important, will not be truly indicative of anaudio product's "sound" until methods of determining the transient accuracy are established. Transientaccuracy is not a "spec" and test benches don't produce hit records. The transient details are important forreproducing the true character of the instrument, the room and stereo image. Most solid state circuits usea large amont of negative feedback to lower noise and distortion at the cost of transient accuracy. Thispreamplifier started out clean and quiet so minimal negative feedback was necessary.Op-amp based designs, by comparison, have dozens of transistors in each "chip" (its easier tofabricate a transistor than a resistor on silicon), hundreds of dB's of negative feedback and sometimes a fewdiscrete transistors to provide performance that an "IC" simply cannot. The result is good specs - but thatharsh, hard, cold sound that makes shakers sound like pink noise, makes vocals sibilant in an unpleasantway, and can only render a 2 dimensional image at best. We prefer tubes or simple discrete circuits.We mentioned mic signals are fragile and raw. Some consider that the "headroom" factor is the mostimportant issue in mic pre's. We believe that it is just one of a number of issues including the harmoniccharacter of the distortion. Except for the final output, all circuits are "Class A" which is usually associatedwith zerocrossover distortion and near clipping will be even order distortion and less upper harmonics.ThisPreamplifier has more headroom than most solid state mic pre's because of the 48 volt power supply used,compared to 30 volts (+/- 15V or 24 volts) used in other designs. If overdriven, which is not easy, it startsto clip in a gentle, smooth way.Another consideration above and beyond technical concerns when it comes to the art ofrecording music is that every preamp seems to have some comparative influence on the"sound" of the mic signal. When we have a choice, we tend to use the preamp that either bestflatters the singer or instrument or gets closest to the desired final sonic goal. Sometimes, thechoice is the clean & pristene pre and sometimes it is the vintage or aggressive box but itseems to be getting rarer that we choose the basic console mic preamps. The Dual VocalCombo is typically considered "clean but vintage" and not as "dry" as many all-discrete micpreamps. People have used the words "smooth" and "strong" to describe it but undoubtedlyyou will find your own words to descibe it compared to your console and other units.