MICROPHONE PREAMPLIFIER SECTION:
The preamplifier is a clone of a highly regarded and popular mic pre: the Manley Mono Microphone Preamplifier! The mic input transformer is our own design wound in-house at the Manley Labs factory. High current 48V Phantom power is switchable from the front panel. A simple and effective passive BASS CUT switch kills rumble and reduces popping. The INPUT ATTENUATOR is a variable pad control situated before the first tube stage allowing the preamplifier to accommodate +4 line level signals via the balanced LINE INPUT and instruments via the front panel 1/4" DIRECT INPUT. These inputs are selected in the middle position of the dual-function phase invert switch. We provide both transformer balanced XLR output as well as a transformerless "audiophile" 1/4" phone jack output. The Gain switch is actually a clever variable feedback control that changes not only the gain but the slew rate and flavor of the circuit. With it you can choose how laid back and mellow or how up-front and aggressive you want it to get. See "Notes on Variable Feedback" for more info. Headroom is a strong point in this circuit, +31dBu capable. This is 5 to 10 dB better than almost all other pro gear. The music passes through only our super-clean pure Class A vacuum tube circuitry. There are obvious advantages to our purist approach and foremost is the un-electronic final sound that carries emotion into the digital realm.

COMPRESSOR SECTION:
This cool compressor design takes our opto-isolator approach of the Manley ELOP® Limiter to the max. We adjusted the Ratio down to 3:1 to turn our ELOP into a compressor and added ATTACK and RELEASE controls for more versatility. What is clever is how the signal is compressed before it hits the tubes with no detrimental effect on distortion or frequency response. This way, it can prevent mic-pre clipping and eliminate whole stages of electronics. This cuts the typical path of mic to tape in half! We also pioneered new thinking in the sidechain by using up to four different time constants simultaneously and controlling them with familiar simple attack, release and threshold controls. We call the approach "Parametric Compression". We developed optimum settings or presets based our favorite Vactrols that we use in our own fast ELOP® Limiter, the quick LA-2A's T-4 module, the slower LA-3A and then created more complex special settings. This extended range and method of timing delivers fresh sounds from powerhouse punching drums to super-solid bass yet can also emulate the way good engineers delicately ride a fader while recording. It is transparent and liquid-smooth on vocals, easy to use and accurate. Also rare for an opto-based dynamic processor, this compressor works great on mixes. Of course, you'll be needing two VOXBOXes linked in stereo...

EQ SECTION:
Lots of folks requested that we include the Pultec Mid Frequency Equalizer in the VOXBOX®, but they wanted MORE.... Now we've extended it to 33 frequencies in 3 bands with 6 new frequencies from 20 Hz to 150 Hz, and 6 more in the highs from 6.4 KHz to 20 KHz. Ever notice that only EQs with real inductors have the bottom end magic or that only Class A circuitry can keep the top end sweet? This is for you. The EQ INPUT switch patches in the Line Input, Preamp Output, or the INSERT return. This switch serves double-duty acting as a bypass switch for the preamp and/or external processors or for processing two different tracks.

DE-ESSER & LIMITER SECTION:
Designed by folks with admittedly large gaps between their two front teeth, the VOXBOX® combo also includes a de-esser & peak limiter based on our original ELOP® Limiter design but with an added passive LC network to handle the de-essing four carefully chosen notch frequencies from 3KHz to 12KHz. (That 3KHz setting really tames those annoying frequencies!) The fifth position gives you a limiter which totally mimics the famous LA-2A. This means you can both compress pre-EQ then limit here post-EQ. Another cool feature is the ability to insert this de-esser silently and smoothly as the music plays, using it as needed.

THE METER:
The METER is a full size illuminated Sifam VU meter. A five-position switch shows three audio levels: the line input, the preamp output and the final output. It also shows compressor gain reduction and the de-esser/limiter action. Other clever innovations incorporated into the VOXBOX® combo include warm-up muting circuitry, extensive magnetic field containment, 'smart -grounding', and silent switching. The sum-total is more than the separate parts: consider the reduced patching, the short path to tape and you having this much immediate control. As engineers, we choose what we use not based entirely on features and functions - there is a sound, a texture we reach for and the VOXBOX® combo puts the 'Manley Sound' together with 'Your Sound'.

• MANLEY transformers w/nickel laminations in mu-metal cases

• 2 kOhm MIC INPUT Z w/High current 48V Phantom power built-in

• Hi-Z (100K) Direct Instrument Input

• LINE & INSERT INPUTS (balanced XLR & 1/4")

• PREAMP & EQ outputs LO-Z (50 Ohms)

• Transformer balanced XLR outputs

• Transformerless unbalanced 1/4"outputs

• STEREO LINK for Compressor & De-esser/Limiter

• SIDE CHAIN MONITOR for De-Esser

• Large ILLUMINATED Sifam METER with FIVE readout modes - (older units before serial number MVB**1359 shipped before 9/2003 use: 12V 1.2W FESTOON LAMPS; Manley's Part Number: VAR016C) Order spare bulbs using our parts order form. (newest units after serial number MVB**1359 shipped after 9/2003 use yellow LED lighting)

• THD + N (1KHz @ +20 dBu): 0.3%

• Maximum output: +31dBu


MIC PREAMP SECTION
Frequency Response: ±1dB 20Hz - 60KHz

Noise Floor (A-wgt): -86 dB

Signal to Noise Ratio: 113 dB

Tube complement: 12AX7 & 12BH7 (or 6414)

Gain: 40-60 dB

EQ SECTION
Frequency Response: 10 Hz - 100 kHz

Noise Floor (A-wgt): -89 dB

Signal to Noise Ratio: 116 dB

Tube complement: 5751 & 12BH7 (or 6414)

Gain: unity

GENERAL INFO
Power Consumption: 24 Watts

Mains Voltage Frequency: 50~ 60Hz

Dimensions: 19" x 5.25" x 10" - occupies 3U

Unit Weight: 14 lbs.

Shipping weight: 21 lbs.
OPERATING MAINS VOLTAGE: Units are purpose built for original destination country's mains voltage: 100V, 120V, or 220-240VAC as indicated on the serial number badge. Power transformer must be replaced in order to change mains operating voltage. 120VAC units may NOT be rewired to put the primaries of the power transformer in series for 220-240V operation or a large radiated field of hum will develop. If changing locations/voltages, the power transformer must be replaced with the dedicated one for the voltage at which it will operate and the mains fuse must be changed.
Mains Fuse Value for 120VAC = 1 Amp Slo-Blo 1/4” x 1 1/4”

Mains Fuse Value for 240VAC= 1/2 Amp Slo-Blo 1/4” x 1 1/4”

Manley Voxbox Manual