OWNER'S MANUAL MANLEY VOXBOX MANLEY LABORATORIES, INC. MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. 91710 TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley @ netcom.com http://www.manleylabs.
CONTENTS SECTION PAGE INTRODUCTION FRONT PANEL 3 MIC PRE COMPRESSOR EQ & DE-ESSER 4 5 6 BACK PANEL 7, 8 & 9 GENERAL DISCUSSION OVERVIEW AND BLOCK DIAGRAM MIC PREAMP COMPRESSOR EQ DE-ESSER 10 11 12 13 14 & 15 SAMPLE SETTINGS 16 TECHNICAL DETAILS MAINS CONNECTIONS 17 TUBE, TRIMMER & JUMPER LOCATIONS 18 CALIBRATION 19 TROUBLESHOOTING 20 & 21 SPECIFICATIONS 22 CURVES 23 & 24 WARRANTY 25 WARRANTY REGISTRATION 26 APPENDIX 1 - TEMPLATE FOR STORING SETTINGS 27
INTRODUCTION THANK YOU!... for choosing the Manley VOXBOX. This unit is the result of our customers asking us to make a vocal oriented combination from some favorite Manley designs. We combined the Manley Mic Preamplifier, Electro-Optical Limiter, and Mid Pultec and then went further. Uniquely, we put a compressor before a minimalist mic preamplifier.
FRONT PANEL A B C D E H J K N W X ON Y 9 KHz DE-ESS Z THRESHOLD POWER OFF ON MID DIP HIGH PEAK 12 KHz READY PHANTOM 48 VOLTS BYPASS 120 80 FLAT MANLEY VOXBOX PHASE / IN 0˚ INST LINE 180˚ THRESHOLD EQ IN COMPRESS 3:1 BYPASS INPUT ATTACK GAIN PRE O/P 50 F MEDIUM 42 MED SLOW 40 SLOW G I EQ INPUT INSERT MED FAST 45 L 0 BYPASS RELEASE FAST EQ OUT DS LINE IN GR 48 LOW PEAK PRE O/P LINE IN M O P +10 0 0 200 300 500 700 1K 1K 700 500 300 200 +10 6K4 1K5
COMPRESSOR SECTION J COMPRESSOR BYPASS: With this switch up the compressor is engaged. This switch is uniquely designed to be used during music. No clicks, no pops and the change of level occurs smoothly. The compressor is uniquely before the preamp so that transients are "tamed" before the signal enters the tube circuit. This makes it possible to have exceptionally clean, smooth tracks.
EQ and DE-ESSER SECTION O EQ BYPASS: Switching this up engages the EQ section. This is a passive PULTEC MEQ style EQ with only one capacitor, one inductor (coil or choke) a conductive plastic pot and a gold contact switch in the audio path for each band of EQ. There are no tubes in the EQ and certainly no ICs or transistors. The tube circuit is only used for flat, fixed make-up gain and is always in circuit. The EQ is before the de-esser / limiter and before the tubes.
REAR PANEL Q P O N M L K J EQ OUT STEREO LINK COMPRESSOR CE INSERT INPUT I H G PREAMP OUT LINE INPUT F MIC INPUT THIS SPACE FOR SERIAL NUMBER STEREO LINK DE-ESSER HANDCRAFTED IN USA MANLEY LABORATORIES 13880 MAGNOLIA AVE., CHINO, CA 91710 PHONE (909) 627-4256 FAX (909) 628-2482 email: emanley@netcom.com TO PROTECT SPEAKERS: CAUTION: RISK OF ELECTRIC SHOCK. DO NOT OPEN. REFER ALL SERVICING TO QUALIFIED PERSONNEL ONLY. WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK.
H LINE INPUT. XLR For balanced or unbalanced +4 line level sources. Transformer coupled. The PINOUT is : PIN 1 = CIRCUIT GROUND = SHIELD PIN 2 = HOT = positive going signal + PIN 3 = LOW = negative going signal - I PREAMP OUT (PHONE JACK). The signal from the mic preamplifier and compressor before the transformer. It is designed to be the cleanest output for direct to tape recording. The output phone jacks are different from the inputs.
O LINK COMPRESSOR: This RCA is used for connecting to a second VOXBOX. The signal on this connector is a changing DC voltage from the compressor section. It is both an input and an output. You can link the second VOXBOX with any typical hi-fi RCA interconnect as long as it is not longer than 6 feet. P LINK DE-ESSER: This RCA is used for connecting to a second VOX BOX.
OVERVIEW and BLOCK DIAGRAM GAIN SWITCH BALANCED OUTPUT BLOCK DIAGRAM INSERT INPUT BALANCED OUTPUT MIC IN PHASE INST IN COMPRESSOR INPUT LEVEL NEW PASSIVE OPTO CIRCUIT EQUALIZER OUR 40 dB TUBE PREAMP PASSIVE EQ PULTEC STYLE UNBALANCED OUTPUT LINE IN TRANSFORMER SYMBOL MIC PRE SWITCHING PHONE JACK DE-ESSER LIMITER LINE AMPLIFIER PASSIVE OPTO TUBE CIRCUIT UNBALANCED OUTPUT TUBE GAIN STAGES This block diagram is intended to give you a reasonable view of the signal flow in the VOXBOX.
THE MIC PREAMP & COMPRESSOR The VOXBOX can be divided into two main sections. The first is the Compressor and Mic Preamplifier. The input signal can be a microphone, instrument or line level signal. The mic and line inputs are on the back panel. The mic input is transformer balanced with 48 volt phantom power available, switched from the front. The line input has both XLR and 1/4 inch phone jacks and will accept balanced or unbalanced signal at either of the jacks.
The LOW FREQUENCY ROLL-OFF switch works on mic, line and instrument inputs. We use it to reduce room rumble, excessive proximity effect and sometimes to achieve hotter overall levels. It reduces bass a bit gentler and smoother than most mic pre filters. It is 6 dB per octave, rather than 18 dB per octave. A little note about the INPUT control. This control is before any other circuitry that might distort. In a sense, it is a variable pad.
A note regarding how we've described LA-2A's as fast and LA-3A's as slower. Your experience may disagree with our generalization. They both used the same opto part # and should be the same. We believe there was a fair amount of variation over the years and we know of slow and fast versions in both models. The LA-2A we used to compare was a faster type and the LA-3A was slower. Perhaps a better description is simply "slow and fast vintageopto" but we did emulate and compare with real vintage units.
The MID DIP section has a number of typical uses. Most condensor mics have a peak in the frequency response. It is the normal resonance of the diaphram and is typically in the 5 kHz to 10 kHz range on the large diaphram mics that we tend to favor for vocals. Sometimes you can often get a sweeter sound by dipping a little at 5K or 7K and then boosting frequencies above 12K. It may be important to find a good balance between "presence" or "cut" and "breath" or "air".
Is there a way to prevent the sibilance problems and still get an airy bright vocal sound without resorting to a de-esser? Usually, yes. "Boosting too much highs " normally gets the blame but that may be an over-simplified view and not always accurate. Modern pop productions almost demand that bright airy sound that can only be arrived at by boosting highs. The wrong boost frequencies are those that correspond to the resonance of the mic or "whistle" caused by a gap in the singers teeth.
ADDENDUM This page was added just before Thanksgiving 2000, as we update the manuals and converted them to PDF format and finally get them up on . Originally this page was supposed to show some user settings and we invited everybody to contribute. Nobody did, so this page was blank for 3 years. So now, we can use it for some collected comments and hints we have had since the introduction and for some info on versions and updates.
MAINS CONNECTIONS Your Limiter 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. If your unit does not have a plug fitted the coloured wires should be connected to the appropriate plug terminals in accordance with the following code.
TUBE & TRIM LOCATIONS 12V FILAMENT REGULATOR POWER ON?OFF MUTE LINE IN L LINE IN TRANS BYPASS F E INSERT IN PRE OUT CHASSIS GND XLR PIN 1 CIRCUIT GND EQ OUT POWER TRANSFORMER 2) 300V B+ REGULATOR 2) MULTICAP OP COUPLING D E M E E M EQ IN SELECT & MUTING 6414 6414 +15V & -15V REGULATORS EQ = UNITY GAIN 5751 6072A GND OPTO DS / LIM CAL METER DS GR CAL 6 7 3 METER GR ZERO SET MIC IN 1 OPTOS 2 4 5 EQ CAPS AND INDUCTORS METER LAMP = 12 VOLT, 100 mA, .91" X .
CALIBRATION PROCEDURE This procedure has been done by the factory and should not be re-adjusted unless absolutely needed and should only be done by a qualified technician. There are potentially painfull high voltages inside the VOXBOX so care should be taken even by good technicians. They have been known to get a shock but they also know to use one hand and insulated tools or gloves. The function of each trim is labeled on the diagram on the previous page (page 15).
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. If you suspect a problem the following paragraphs should help. NO POWER, NO INDICATORS, NADA - Probably something to do with AC power. Is it plugged in? Check the fuseon the back panel. A blown fuse often looks blackened inside or the little wire inside looks broken or it's resistance measures higher than 2 ohms.
IT MAKES NOISES WHEN THE FRONT PANEL IS TAPPED - An easy one. Some tubes become microphonic over time. That means they start acting like a bad microphone. Vibration has caused the supports for the little parts in the tube to loosen and now the tube is sensitive to vibration. Easy - Replace the tube. Which one? The one that makes the most noise when you tap it. Usually this will be one of the smaller (gain stage) tubes closest to the front.
SPECIFICATIONS MANLEY VOX BOX PREAMPLIFIER EQ SECTION BOTH Maximum Output : 1.5% THD Unbalanced: 20-20K Balanced: 1 KHz +31 dBv +31 dBv ` +31 dBv +31 dBv +31 dBv +31 dBv Headroom (referenced to +4 dBv) 27 dB 27 dB 27 dB THD & Noise (1kHz @ +20 dBm) .3% .3% .
5 6.2 8 10 12.5 16 20 25 32 40 50 62 80 100 125 160 200 250 320 400 500 620 800 1K 1.25 1.6 2K 2.5 3.2 4K 5K 6.2 8K 10 12.5 16 20 25 32 40 50 62 80 100 +12 LOW PEAK THE 20 KHZ POSITION IS PURPOSELY A BROADER "Q". A NARROW "Q" AT THIS FREQUENCY WAS BARELY AUDIBLE. +11 +10 +9 HIGH PEAK THE 20 HZ POSITION LOOKS HIGHER IN FREQUENCY AND LOWER IN RANGE BECAUSE OF THE INHERANT ROLL OFF OF THE OVERALL CIRCUIT. (-3 DB @ 12 HZ.
WARRANTY All Manley Laboratories equipment is covered by a limited warranty against defects in materials and workmanship for a period of 90 days from date of purchase to the original purchaser only. A further optional limited 5 year warranty is available to the original purchaser upon proper registration of ownership within 30 days of date of first purchase.
WARRANTY REGISTRATION We ask that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO CA, 91710 Registration entitles you to product support, full warranty benefits, and notice of product enhancements and upgrades. You MUST complete and return the following to validate your warranty and registration. Thank you again for choosing to use Manley Laboratories. MODEL ____________________ SERIAL No.