LANGEVIN DUAL VOCAL COMBO OWNERS MANUAL rev4.5.
CONTENTS SECTION PAGE INTRODUCTION 3 FRONT PANEL 4 BACK PANEL 6 MIC PRE BASICS 7 CONNECTING YOUR PREAMPLIFIER 8 OPERATION NOTES 10 SPECIFICATIONS 12 TROUBLESHOOTING 13 INTERNAL ADJUSTMENTS 15 INTERNAL LAYOUT 16 REPLACING FUSES 17 MAINS CONNECTIONS 18 APPENDIX A: WIRING YOUR OWN CABLES 19 APPENDIX B: TEMPLATE FOR STORING SETTINGS 20
INTRODUCTION THANK YOU!... for choosing the Langevin Dual Vocal Combo. Manley Labs bought all the rights to the Langevin name and circuits in 1992. Manley uses the Langevin name for its solid state products including versions of an all discrete Pultec and Electro-Optical Limiter, and Mic Preamp.
FRONT PANEL AA BB CC DD EE INPUT 80 Hz L.F. EQ IN H.F. G HH II H H G G FF G 12 KHz POWER OFF ON PHANTOM PHANTOM by Manley Laboratories Inc. (PULLON) ATTENUATE 40 Hz DIRECT INPUT IN -10 +10 GAIN EQ OUT -10 REDUCTION +10 8 KHz F F E E DD 80 Hz L.F. EQ IN CC H.F.
J) DIRECT INPUT. This is for plugging in an electric guitar, bass, synth, etc into the Dual Vocal Combo. The input impedance is high (150 kOhms) appropriate for these instruments and there should be plenty of gain available. Electric guitars and basses may need a fair amount of H.F. Boost to sound comparable to an amp because there happens to be a lot of H.F. boost going on in the innards of most amps. A jack plugged into this input will interrupt the normal mic XLR input.
REAR PANEL MIC IN BALANCED LINE OUT PREAMP OUT OUT UNBALANCED ONLY AA BB OUT UNBALANCED ONLY AN EVEANNA MANLEY PRODUCTION MANLEY LABORATORIES 13880 MAGNOLIA AVE., CHINO, CA 91710 PHONE (909) 627-4256 FAX (909) 628-2482 email: emanley@manleylabs.com MIC IN PREAMP OUT N9512423 POWER CIRCUIT REPLACE FUSE WITH SAME TYPE AND RATING LIMITER IN BALANCED LINE OUT GROUND LIMITER IN CHASSIS CAUTION - RISK OF ELECTRIC SHOCK. DO NOT OPEN.
MIC PRE BASICS This Microphone Preamp, like most mic preamps, is pretty easy to use. First we can discuss why outboard mic preamps have become “a must have item” in almost every studio even though your console probably has a bunch of them and that manufacturer claims that they are really great and you don’t need outboard mic preamps. Then, why is everybody buying them, using them, and why are most people going back to tubes or vintage transistor based circuits? Good question.
CONNECTING YOUR PREAMPLIFIER Easy - Connect the mic to the Microphone Input XLR, then connect the Line Output to your tape 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 signal from 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 be damaged by the 48 volts of phantom power.
Reversing the polarity or phase is often needed when two or more mics are picking up the same source. For example it would be needed when one mics the top and bottom of a snare - one skin is going towards one mic and the other skin is going away from the other mic. If one signal is not “reversed” then you lose lows. Polarity reverse can also help with some vocal / mic / headphone situations because “ somewhere “ the polarity flipped one too many times. It happens.
OPERATION NOTES The Langevin Electo-Optical Limiter follows certain traits and traditions established by the UREI LA-3A and similar levelling amplifiers. These traits can be divided into two aspects - electronic and operation. The electronic concept is simple and rather clean. Use the audio to light up LEDs which shine onto photo-resistors. These photo-resistors in combination with a fixed resistor simply act as a voltage divider to attenuate the signal.
The slope or ratio is also difficult to simulate. The initial ratio is low and becomes higher with more gain reduction until the leds light up fully and further reduction is not easy. This upper limit of reduction is in the area of 20 dB or at the bottom of the GR meter where the ratio becomes low again but this would be a severe setting that few engineers could use. Distortion becomes audible at very deep limiting.
SPECIFICATIONS Frequency Response 10 Hz to 20 KHz THD & Noise .075% .
TROUBLE-SHOOTING There are a number of possible symptoms of something not quite right, some may be interfacing, others we will touch on as well. The Dual Vocal Combo has a variety of balanced and unbalanced inputs and outputs optimised for typical standards and most problems are due to the right cable in the wrong jack. However if you suspect a problem the following paragraphs should help. NO POWER, NO INDICATORS, NADA - Probably something to do with AC power.
HUM - Let’s assume it knows the words. Once again - several possibilities - several cures. Most likely it is a ground loop. The two most common procedures are: try a 3 pin to 2 pin AC adapter (about a dollar at the hardware store) which is better than messing up the power cable by bending the ground pin until it breaks off. Method two - cutting the shield on one side of the cable. This is usually done at every female XLR to “break” all loops. You may get a loop simply from the rack.
INTERNAL ADJUSTMENTS (see layout on page 16) 1) +45 Volt DC adjust with meter from ground to resistor marked by arrow. Check this first and adjust if needed. It is the power supply regulator adjustment. Now for the audio .... You will have to start out by setting front panel controls to these settings: BYPASS mode, SEP / LINK OFF, REDUCTION controls counter clockwise (MIN), GAIN to 1:00 or unity, Balance at 12:00. The top will need to be open.
12 6469 MIC INPUT XFMR 2 11 DIRECT INPUT GAIN MICPRE GAIN GAIN METER CAL "OUTPUT" PRINT AND INSERT IN OWNWERS MANUAL AS PG. 16 ERASE THIS NOTE FIRST 4 LANGEVIN DUAL VOCAL COMBO PCB VER. 2001 S/N'S LDVCP 6 8 LINK ADJ.
REPLACING FUSES 1 2 Phantom Volts Fuse = AGC 4/10A Fast blow Changing the fuse is easy and can be done without any tools and while the DVC is still in a rack. 1) Disconnect the IEC AC mains for safety 2) Rotate the fuse cap anti-clockwise 1/4 turn 3) Remove the fuse and replace it with a new fuse of the same size, type, and rating (see next page for details) 4) Reconnect the IEC AC mains, turn on the power and meter lamps should once again glow.
MAINS CONNECTIONS Your Dual Vocal Combo has been factory set to the correct mains voltage for your country. The voltage setting is marked on the serial badge, located on the rear panel. Check that this complies with your local supply. Export units for certain markets have a moulded mains plug fitted to comply with local requirements.
WIRING YOUR OWN CABLES ? XLR MALE VIEWED FROM THE BACK OR SOLDER SIDE 1/4" MONO PHONE JACK TIP XLR MALE VIEWED FROM THE SIDE SLEEVE SHELL TIP SLEEVE 2 1 3 1/4" STEREO PHONE JACK TIP RING SLEEVE RING TIP XLR FEMALE VIEWED FROM THE BACK OR SOLDER SIDE XLR MALE VIEWED FROM THE SIDE SLEEVE SHELL 1 1/8" STEREO PHONE JACK R T 2 3 S BANTAM (PATCHBAY) JACK RING TIP R T S MANLEY GEAR - THIS PAGE CAME WITH GEAR WITH TRUE TRANSFORMER BALANCED XLR INPUTS AND OUTPUTS.
by Manley Laboratories Inc. TEMPLATE -photocopy this page and use it to store settings INPUT 80 Hz ATTENUATE 40 Hz DIRECT INPUT IN L.F. -10 EQ IN +10 GAIN EQ OUT H.F. -10 REDUCTION 12 KHz +10 8 KHz POWER PHANTOM (PULLON) 80 Hz 40 Hz METER OUTPUT L.F. -10 EQ IN +10 METER OUTPUT EQ OUT REDUCTION H.F. -10 +10 GAIN 12 KHz INPUT 8 KHz ATTENUATE IN DIRECT INPUT LINK LIMITER REDUCTION REDUCTION PRODUCER: STUDIO: ARTIST: TRACK: NOTES: by Manley Laboratories Inc.
