This processor is the stuff legends are made of.
Manley Laboratories is this country's biggest little manufacturer of modern, high-end tube gear. Manley products such as the Vox Box, Massive Passive equalizer, and Variable-Mu stereo compressor are glowing beacons of warmth in this digital age. They are also, sadly, too expensive for most EM readers, so they rarely appear in these pages. Thankfully, personal-studio owners can now reap the benefits of Manley's no-compromises approach to circuit design with a full range of solid-state boxes branded with the historic Langevin name.
The Langevin Company was founded in 1923 in New York. Throughout its 50-year history of manufacturing transformers and radio-broadcast equipment, the company went through a series of ownership and name changes. After moving around the country, Langevin relocated to Los Angeles in the early 1960s. Langevin mixing consoles found their way into a number of recording studios, and the company's AM16 mic-preamp modules remain a hot item on the vintage-pro-audio market today.
In 1992, Manley Laboratories acquired the rights to the Langevin name and designs and has since given the Langevin name to all of its solid-state processors. In addition, Manley made critical improvements to some of the original Langevin circuit designs. Though it's tempting to think of Langevin as Manley's budget line, the price and quality of the various models I've seen easily put them in the same ranks as the best contemporary Class A and solid-state units.
The most versatile and deluxe Langevin offering to date, the new Dual Vocal Combo combines the attributes of the Dual Mono Microphone Preamplifier with EQ and the Dual-Channel Electro-Optical Limiter (or El-Op). The Dual Vocal Combo also provides a direct input for each channel, making the unit a full-featured pair of "channel strip" processors that goes well beyond the limitations suggested by its name. Techies will appreciate that the microphone input uses a Manley Labs custom-wound transformer and is all-discrete Class A, with no integrated circuits or op amps in the signal path.
TOUR DE FRONTThe Dual Vocal Combo's uncluttered rose-red aluminum front panel sports a symmetrical layout of switches, knobs, and meters for each channel. The mic-preamp and EQ functions are organized across the top of the 2U front, and the DI jacks and limiter section occupy the bottom half of the panel face.
The AC power switch lies in the center of the top row, flanked by a fancy pair of locking phantom-power switches with yellow status lights. In the middle of each upper-panel half are the EQ sections, which contain two continuously variable low- and high-frequency shelving controls (-10 to +10 dB) with switchable 40/80 Hz and 8/12 kHz corner frequencies, as well as an EQ bypass for each channel. The EQ gain pots have no calibration markings (none of the pots have detents, zero-gain indications, or numerical gain values of any kind), but all of the rotary knobs on the Dual Vocal Combo are encircled by a white ring with ten equal divisions, five on each side of the center line. (In the case of the EQ knobs, these could be interpreted as 2 dB divisions.)
The preamp gain controls, labeled "Input Attenuate," are located on the outer edges of the mic-preamp sections. The name may seem rather obscure, but these controls are actually trim pots designed to keep the input from overdriving the preamp section. Despite the subtle nomenclature, the Input Attenuate knobs function just as conventional gain controls do: when they're turned as far as possible clockwise, the mic preamp operates at a factory-set rating of 45 dB, with both channels matched for identical maximum output.
Located directly beneath the Input Attenuate knobs are high-impedance (150 kz) direct-input jacks. When you insert a 11/44-inch guitar cable into the DI jack, the microphone input is interrupted, and all the resources of the Dual Vocal Combo (including up to 25 dB gain) are available for shaping the sound of electric guitars, basses, keyboards, and so on.
LIMITING FACTORSThe remainder of the lower front panel is dedicated to the limiter block, which uses the unique response of a light-sensing Vactrol cell to control a fast-attack, slow-release, high-ratio compression circuit. In the center of the limiter section are two Sifam VU meters (which display either +4 dBm output level or the amount of gain reduction) separated by a switch labeled "Sep/Link." This switch lets the left and right channels operate either independently (for processing two different signals) or together (for stereo operation). For example, you would select Link to limit a stereo recording or mixdown. To enable smoother and more musical gain reduction, the Dual Vocal Combo limiting circuit, when linked, is controlled by a summed combination of the two channels rather than by only one channel, the more common (and less expensive) method of triggering gain reduction.
The limiter section, in keeping with the conventions of popular vintage limiters such as the UREI LA-3A, provides only two controls: makeup gain (labeled "Gain") and threshold (labeled "Reduction"). Clockwise movement of the Reduction knob lowers the compression threshold, which results in more peaks being limited and reduces the dynamic range of the signal. Due to the unique characteristics of the Vactrol sensing cell, the audible effect of the limiting circuit changes subtly as the threshold is lowered and gain reduction increases. For most sources at minimal settings (up to 4 dB of gain reduction), the electro-optical limiter works more or less invisibly, with no ducking, transient squashing, or brickwall leveling in evidence. Used to compensate for the overall reduction in peak or RMS level, the makeup-gain control can also be used to add up to 15 dB of gain at the final output stage. This knob has no unity-gain or zero marking, which seemed a little strange. By trial and error I found the unity position near 1 o'clock on the rotary pot's outer ring, and I made a mental note to use this position as a starting point for future tests.
The last component in the section is the limiter Bypass switch. As the chatty yet highly informative manual wisely states, "This should be the most used control on your limiter." The Bypass switch allows you to precisely set makeup gain by ear, as well as make an A/B comparison of uncompressed and compressed signals to determine the desired amount of limiting.
AROUND BACKOn the rear panel is the usual complement of IEC power-cord connector and fuse holder, along with separate chassis- and circuit-ground terminals. These grounding points, which are normally jumpered together, can be accessed individually to reduce hum and ground loops. The microphone inputs and balanced +4 dBV outputs are gold-plated Neutrik XLR jacks. Two 11/44-inch jacks are also provided: an unbalanced out at professional +4 dBV level (not consumer/semipro -10 dBu level, as is conventional for most unbalanced lines) and a TRS input jack for the limiter section.
Inserting a cable into the TRS jack enables a mechanical disconnect of the limiter, allowing the limiter section to be used essentially as a stand-alone unit - equivalent in every way to the $1,775 Langevin El-Op. My only wishes here are that the limiter input was on an XLR jack - or even on both kinds of jacks - and that there were consumer-level outputs so as to standardize connection with the mixture of gear in my racks.
NO REVERSALThe only other feature that I missed on the Dual Vocal Combo was a simple phase-reverse switch. In my perfect world, these switches (which can correct wiring anomalies and assist in checks for phase cancellation in multimic setups) are standard equipment on every mic preamp. This common feature is very handy, and certainly far more convenient than inserting a phase-reverse cable, especially when you're working with phantom-powered condenser mics.
SAX APPEALIn my studio, the Dual Vocal Combo quickly became my favorite new toy. The biggest challenge it faced was recording a saxophone quartet, with all parts multitracked by arranger/player Jamison Reed of the popular Bay Area band Casino Royale. I'm known for being pretty picky about sax sounds (as is Reed, a veteran performer), and at the start of the session I vowed to abandon the Langevin the moment that it overcompressed, ran out of gain, or added unwanted coloration and harshness to this delicately balanced piece. As it turned out, my concerns were quickly allayed.
On the first track - the baritone-sax part - my Lawson L47MP tube microphone's tone sounded robust and clear, and the Langevin limiter kept the popping low notes of this dynamic horn in check with only 2 to 3 dB of gain reduction. There were no problems with the tenor sax, either, except for some uncharacteristic dullness of sound, which a touch of high-shelving EQ remedied nicely. Though I usually think of the high reeds as the most difficult to capture without fizziness or excessive upper midrange - especially when I'm using a solid-state preamp - the Langevin helped deliver what I'm proud to say are some of my best-recorded alto and soprano sax sounds.
Of course, the microphone and source are the key factors in a recording of this type, but it's up to the preamp to pass along every nuance and deliver the track with all its tonality and musicality intact. The Dual Vocal Combo gave me all the control I needed, with plenty of gain, ultralow noise, and effective, highly refined EQ and limiting. Judging by the cumulative timbre of this one-man sax quartet, I give the unit high marks for its tightly focused sound, useful features, and excellent tonal balance. The resulting sound was airy but never overly bright, even on piping soprano notes.
VOICE OF REASONWhen recording vocals (as well as other lead instruments, such as saxophone), I need a preamp that provides not only accuracy and the ability to capture every utterance - no matter how quiet - but also some attitude. This puts the vocal track right up front in the mix. For this application, I typically default to a Focusrite Red 7, a single-channel preamp with compression that costs significantly more than the 2-channel Dual Vocal Combo.
Paired with the Lawson L47MP and the revealingly airy BLUE Bottle mic, the Langevin certainly held its own in warmth and nuance when used on the voices of two male singers (including the challenging falsetto of Martyn Jacques of London's infamous Tigerlilies). The Dual Vocal Combo gave a very immediate, detailed sound that could be described as the proverbial "wire with gain," while the Focusrite Red 7 added a little of its own special sheen to the tracks. In the final assessment, I'd take either preamp to a desert island, and preferably I'd have room in my luggage for both.
As a 2-channel preamp for a matched pair of Schoeps 221b drum-overhead mics in XY configuration, the Langevin really floored me. On four diverse drummers (including EM's Gino Robair and Martin Huge of the Tigerlilies), the Dual Vocal Combo's minimalist circuitry yielded a level of transient detail, precision, and unclouded spaciousness that always perked up my ears. There was no harshness on cymbals, and I never felt that I had to add highs or cut lows to enhance definition of the kit. A little 12 kHz boost was hard to resist, however, given the sweet and utterly transparent nature of the Langevin EQ. Interestingly, I also found myself adding considerably less reverb than I would when using my standard solid-state Class A preamp. By passing the mic signals as cleanly and simply as possible, the Langevin gave a remarkable sense of "etched warmth" to these complex drum tracks.
OFF LIMITSI also used the Dual Vocal Combo's limiter section on its own, primarily as a stereo-bus limiter following a tube compressor (the Manley Stereo Variable-Mu), for final mixdowns to both analog and digital formats. Again, when conservatively used, the electro-optical limiter worked wonders, taming drum and vocal peaks in my mixes without pumping or softening attacks on the drums. Though it is not my standard practice to chain a compressor and limiter on 2-track mixdowns, this arrangement was certainly an ear-opener, yielding screaming levels while retaining punch and dynamics on some heavy-rock tracks.
To get an additional opinion on the Dual Vocal Combo, I loaned the unit to remote-recording specialist Karen Stackpole for a vocal-tracking session. Following her first afternoon with the Langevin, I received a strange phone call: there was no opening "Hello," just a breathlessly urgent, "How much is it?" Stackpole found the unit simple to learn and use, and she noted that it was easy to hear minor adjustments in the limiter and EQ sections. On vocals - tracked to ADAT with the Lawson L47MP - she used up to 6 dB of limiting. Based on the results, Stackpole praised the unit for its smoothness and transparency. She especially appreciated the unit's locking phantom-power switches, and she also rated the user manual highly. In short, she loved the Dual Vocal Combo, summing up its character as "warm sounding and not at all brittle."
BE DIRECTI was pleasantly surprised to find that, when the Langevin was employed as a direct box with a Fender bass plugged into the DI jack, it sounded every bit as good as a Peavey VMP-2 - my favorite American-made tube preamp with DI. Through the Dual Vocal Combo, the bass boasted thunderous lows, clear metallic highs, and marvelous sustain. But I was bothered by a relatively high background hiss in the unit, with some sputtering white noise evident in both channels.
To rule out my own error - and to make sure nothing had gone wrong with the unit since I last used it - I again compared the Dual Vocal Combo's mic preamps with some other mic preamps. But just as before, there was no significant noise problem in the unit's preamp-and-limiter chain. Next, using a jazz guitar with humbucking pickups, I double-checked the Langevin DI against three other level-matched DI/preamp boxes (both tube and solid-state), including a Manley Tube DI. Sure enough, the Dual Vocal Combo's DI channels - both of them, equally - were noisy in comparison with the others. Though the DI is nonetheless useful for a wide range of recording applications - the noise level is no higher than that contributed by a typical guitar amplifier - I expected it to be quieter.
ALMOST A STEALIn a personal-studio market flooded with "do-it-all" boxes, Manley Laboratories stands out from the crowd by having the class and foresight to do the job right with its Langevin Dual Vocal Combo. Almost every function on the unit is truly world-class, and its simple design and pristine sonics should appeal to all levels of the studio market, from project novices to audiophile purists. In addition to performing its intended function as a studio vocal processor, the Dual Vocal Combo is a tremendous all-around box for instrumental recording (especially for drums and other acoustic instruments) and stereo-mix limiting. It also has loads of potential as an all-in-one box for live stereo recording to DAT or CD.
Only a few things keep the Dual Vocal Combo from scoring a grand slam of all 5s in my EM ratings. The noise level of the direct inputs is the only shortcoming in terms of audio quality. It prompted me to knock down that rating by half a point - a disappointment, because otherwise the unit deserves the highest marks. As for features, the absence of phase-reverse switching is my main gripe, along with the lack of an XLR input to the limiter. (In the personal-studio environment, more input types - not to mention -10 dBu ins and outs - are always good.) Less damning are the missing numerical markings for the various rotary controls. The blank knobs could prove inconvenient when you're attempting to notate and apply repeat settings from one session to the next, but Manley has handled the situation well by providing a template page in the owner's manual. I own far more expensive preamps with no calibration marks at all, but this certainly doesn't keep me from using them.
In some situations (for example, recording with ribbon microphones and doing distant classical-style recording) the Dual Vocal Combo's maximum mic-preamp gain of only 45 dB could cause concern. Then again, tapping into the additional 15 dB of makeup gain available in the limiter section - or adjusting the internal mic-preamp trim to its upper limit of 53 dB - should eliminate any such worries. Besides, I confirmed in session use that the Dual Vocal Combo offers clean gain right up to the maximum, with ample headroom and no added noise or "crunchies" when the gain trims are cranked all the way up.
At $2,000, the Langevin Dual Vocal Combo is truly a great deal. Considering that the Langevin Dual-Channel Electro-Optical Limiter alone costs $1,775, it's almost a steal. Despite a self-imposed ban on adding new gear to my racks, I have to admit that I'm swayed by the Dual Vocal Combo's seductive sound and myriad features. This is one unit I don't think I can part with.