MANLEY LABORATORIES, INC. MANLEY VOXBOX OWNER'S MANUAL TUBES RULE brought to you by the clever folks at: MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. 91710 USA TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley@manleylabs.com website: www.manleylabs.com REV.
CONTENTS SECTION PAGE INTRODUCTION 3 FRONT PANEL 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 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 A B C D E H J PANEL K N W X Y LINK ON 9 KHz DE-ESS PHANTOM 48 VOLTS Z 6 KHz 12 KHz 3 KHz LIMIT 6:1 THRESHOLD POWER OFF ON MID DIP HIGH PEAK READY SEPARATE BYPASS 120 80 FLAT MANLEY VOXBOX PHASE / IN 0˚ LINE INST 180˚ THRESHOLD BYPASS PRE O/P 50 INSERT PRE O/P MEDIUM MED 42 SLOW LINE IN SLOW 40 G I L M +10 -10 0 0 +10 EQ INPUT MED FAST DS 45 F RELEASE FAST EQ OUT LINE IN GR 48 0 BYPASS ATTACK GAIN INPUT LOW PEAK EQ IN COMPRESS 3:1 O P
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 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. DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE N M L K J I H G EQ OUT STEREO LINK LEAVE ROOM FOR VENTILATION WHEN MOUNTING PREAMP OUT LINE INPUT HANDCRAFTED IN USA MANLEY LABORATORIES 13880 MAGNOLIA AVE., CHINO, CA 91710 PHONE (909) 627-4256 FAX (909) 628-2482 email: emanley@netcom.
H LINE INPUT. XLR For balanced or unbalanced +4 line level sources. Transformer coupled. The PIN-OUT 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 INSERT INPUT BLOCK DIAGRAM BALANCED OUTPUT MIC IN PHASE COMPRESSOR INPUT LEVEL INST IN NEW PASSIVE OPTO CIRCUIT MIC PRE EQUALIZER OUR 40 dB TUBE PREAMP LINE IN PASSIVE EQ PULTEC STYLE UNBALANCED OUTPUT TRANSFORMER SYMBOL DE-ESSER LIMITER LINE AMPLIFIER PASSIVE OPTO TUBE CIRCUIT UNBALANCED OUTPUT SWITCHING PHONE JACK 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. To change the MAINS FUSE. The MAINS FUSE may be checked by first disconnecting the IEC mains cord from the power supply’s power inlet plug. Then gently push and rotate counter-clockwise the black fuseholder cap located next to the IEC power socket.
TUBE & TRIM LOCATIONS 12V FILAMENT REGULATOR D1 ON = No mute D2 ON = Shorter mute time POWER TRANSFORMER D1,D2 OFF = Factory default mute timer ON E 6414 / 12BH7 INSERT IN PRE OUT M EQ OUT Power turn on delay M E E EQ IN SELECT & MUTING 6414 / 12BH7 MIC IN MULTICAP OP COUPLING 3 OPTOS 7 DS / LIM CAL 12AX7 / ECC83 METER DS GR CAL OPTOS METER GR ZERO SET MULTICAP OP COUPLING Low noise graded 12AX7 / ECC83 +15V & -15V REGULATORS D1 D2 ON 6 1 EQ = UNITY GAIN LINE IN L GND EQ C
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 18).
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% .
20 MORE VOXBOX CURVES 15 10 5 COMPRESSOR THRESHOLD AT MAXIMUM MED ATTACK / MEDIUM RELEASE SHOWS 3:1 SLOPE 0 -5 -10 -15 -20 -20 -15 -10 -5 0 5 10 15 +20 20 15 LIMITER THRESHOLD AT MAXIMUM 10 5 Slope starts at 5:1 quickly becomes 10:1 then towards 20 dB of limiting begins to return to normal.
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 +8 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 transferrable warranty is available upon proper registration of ownership within 30 days of date of first purchase.
WARRANTY REGISTRATION We ask, grovel and beg that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO CA, 91710 USA Or you may FAX this form in to: +1 (909) 628-2482 or you may fill in the online warranty registration form found in the Tech Support section of our website www.manleylabs.
TEMPLATES FOR STORING SETTINGS COPY THIS PAGE LINK ON 9 KHz DE-ESS PHANTOM 48 VOLTS 6 KHz 12 KHz 3 KHz LIMIT 10:1 DO NOT WRITE ON THIS MASTER THRESHOLD POWER OFF ON MID DIP HIGH PEAK SEPARATE BYPASS 120 80 FLAT MANLEY VOXBOX PHASE / IN 0˚ LINE INST 180˚ THRESHOLD BYPASS ATTACK GAIN INPUT PRE O/P 50 INSERT PRE O/P MEDIUM MED 42 SLOW LINE IN SLOW 40 +10 -10 0 0 150 1K5 100 70 200 300 50 500 700 1K 35 20 6K4 1K 700 500 300 200 2K 3K 5K 4K 8K 10K 4K 5K 7K 3K 12
