A New Brand at B&H: Introducing Manley Labs All-Tube Audio



At a time when most manufacturers were content with solid-state designs, Manley Laboratories, Inc. stepped outside the box to produce a line of professional-quality all-tube equipment for recording and mastering studios. Manley’s design philosophy is simply to provide the best-sounding equipment at the best possible price. The company’s 11,000-square-foot building, located in Chino, CA, houses a machine shop, printed circuit-board manufacturing, audio transformer winding, engraving, and silk-screening facilities. All custom design, R&D, assembly, testing, and quality-control processes are performed with precision and pride. 

Why Tubes?

It’s a common misconception that tubes create distortion, or color the sound heavily; however, this is all dependent on production. Manley uses a single-ended, Class-A design that provides exceptional linearity with zero cross-distortion and ultra-low noise. The result is a natural and organic tone that breathes with lifelike realism.

The use of audiophile components, including high-purity wire, gold contacts, silver solder, 1% metal film resistors, film and foil capacitors, Bourns conductive plastic potentiometers, and Grayhill sealed-gold contact switches is constant throughout the manufacturing process. Custom transformers and inductors are hand wound, while every tube is hand selected and tested for low noise and low microphonics. The in-house-produced PCBs are carefully designed with the shortest signal paths, while the over-built power supplies are shielded to afford optimal performance without sonic degradation from interference. The solid enclosures feature CNC-machined, 1/4" steel faceplates and are inlaid with laser-engraved inserts. Stringent quality control ensures that every product leaving the factory upholds the highest standards. 

Microphone Preamplifiers

Mono Mic Preamp

One of Manley’s first products was the Mono Mic Pre, which is now also available in two channels, as the Dual Mono Mic Preamp. The original design was intended for use with capacitor (condenser) mics, but has since been upgraded to a higher output, which accommodates the low output of most ribbon microphones. The gain dial offers a range of 40 to 60 dB in +5 dB increments and uniquely features the use of negative feedback, which allows the user to dial-in a tone from mellow and “tubey” to fast and aggressive. 

Additional features include an input transformer, a phase reverse switch, phantom power, and ¼" direct injection (DI) for instruments and line level sources.

TNT 2-Channel Mic Preamplifier

The TNT, which stands for Tubes, No Tubes, offers two distinctly different sounds in one unit. Many guitarists have found this to be the Holy Grail of processors. They use the solid-state cool side to drive the amplifier’s speaker, while recording its output with a microphone through the tube side.

The tube side, which sounds transparent and warm, uses a cascode circuit for high gain, low noise, and low distortion without applying negative feedback. The variable impedance allows you to find the sweet spot for your microphone, without the distractions of different gain changes due to a special circuit.   

The solid-state cool side offers a pallet ranging from clean tones to heavy distortion. It employs two preamps, with opposite topologies, in tandem. Each preamp uses high and low impedances, respectively, with the impedance switch controlling the amount that each preamp affects the sound. With the impedance control in the center, both low- and high-impedance preamps process the audio signal and are then blended together. The iron control reduces or exaggerates the effects of the output transformer, while the 60’s/70’s switch imparts tape compression characteristics to the signal. 

Both preamps feature phantom power, a phase reversal switch, high pass filters, an instrument input, and LED indicators for level and overload. 


Enhanced Pultec EQP-1A

Another one of Manley’s early products is the Enhanced Pultec EQP-1A, which is also available in two channels as the Stereo Pultec EQP-1A. This updated version of the classic two-band EQ from Pulse Technologies features low- and high-frequency control with the ability to boost and cut simultaneously. Passive hand-wound inductors are used to control equalization, while the all-tube gain block amplifies the sound, yielding high output and low noise. 

Divided into three sections, the Enhanced Pultec offers a low shelf filter with frequency selection, boost, and cut controls. The high boost offers a peak filter with frequency selection and variable bandwidth control, while a high shelf affords cut capabilities over the chosen frequency selection. Utilizing both boost and cut controls simultaneously can result in unique shapes for a broad range of sounds.

Enhancements to the original Pultec design include transformerless inputs and outputs, gain adjustment for amplifier feedback, a rear-panel phase reverse switch, and an expanded frequency selection. 

All Tube Mid Frequency EQ

The All Tube Mid Frequency EQ shares the same features and specifications as the EQP-1A, yet complements it by filling in the gaps of the frequency spectrum to allow precise control over midrange frequencies with sharper bell curves.  

Based on the Pultec MEQ-5, this equalizer uses peak and dip filters. The low-mid band features a frequency selection knob and a peak control knob for boosting, while the dip section cuts at the chosen frequency. The high-mid peak section offers frequency selection and boost control. 

The Mid Frequency EQ also includes transformerless inputs and outputs, gain adjustment for amplifier feedback, a phase reverse switch, and expanded frequency selection. It is especially useful for instruments such as guitars, harmonicas, vocals, and violins that are heavily midrange oriented.      

Massive Passive

Manley received countless requests to incorporate both the EQP-1A with the Mid Frequency EQ into one stereo unit. R&D pored over the designs and came up with a powerhouse of an EQ, aptly named the Massive Passive. Often regarded as one of the best-sounding EQs in the world, it features the ability to boost low-frequency content without becoming boomy, or high-frequency content without being shrill. 

The Massive Passive is a two-channel, four-band parametric equalizer with additional five-band high and low pass filters. Each of four bands offers the familiar Pultec style of control with fixed frequency selection, variable bandwidth control, and cut/boost capabilities. This parallel topology allows for extreme tone-shaping capabilities without over-driving the outputs.

Each band also features individual bypass and switchable peak and shelf filters. The two right bands offer high shelf capabilities, while the left two offer low shelf. In peak mode, the bell shape can be widened or narrowed with the bandwidth control. When a shelf filter is selected and the bandwidth knob turned counterclockwise, the band behaves as normal. Turning the knob clockwise introduces a gradual bell-shaped dip as the slope increases, creating a unique-sounding shape. It’s rare to find an analog eq with adjustable high shelf curves. 

The mastering version of the Massive Passive uses mechanically detented frequency, bandwidth, and gain trim knobs to ensure repeatability, but limits the range of operation. The high pass and low pass filter slopes have been tuned specifically for mastering settings.


Manley offers three flavors of compression/limiting. While all three can handle tracking, mixing, and mastering, each one shines at specific tasks.

Variable MU Limiter/Compressor

In the last decade, the Variable MU Limiter/Compressor has become a standard in mastering houses for smooth and gentle control of dynamic range. It is often referred to as a color box, and is used for mastering, final mixing, and two-bus processing.

The unit applies the same technique as the Fairchild compressor by using the “remote cutoff,” or the re-biasing of a vacuum tube to achieve compression, resulting in a smooth change in gain. The compressor setting offers a soft-knee 1.5:1 ratio, while the limit mode offers a sharper knee, with ratios from 4:1 to 20:1. The unit can be used to create distortion effects by turning up the input and lowering the output while using little or no compression.

The input section has a ganged input, but still processes two independent channels by using separate threshold and output controls. There is a side-chain high pass filter, which causes the compressor to not respond to heavy bass material, thus preventing unwanted pumping or other artifacts. 

The Variable MU is available with two mods. The T-Bar mod provides a converter board that uses two 6BA6 tubes instead of the stock 5670 dual-triode tube. This mod allows the Variable MU to sound and perform nearly identically to the original 6386 tube, which became obsolete and unobtainable. This mod sounds less squashed at higher limiting settings, with fewer artifacts, when compared to the stock 5670-tube design. 

The M/S (Mid/Side) mod offers stereo encoding and decoding with image enhancement. When engaged, the left side’s compressor controls the mid, sum, or mono, while the right side controls the side, or difference part, of the sound.

There is an additional version of the Variable MU with both the M/S Mod and T-Bar Mod. The Variable MU Mastering Version replaces all conductive plastic pots with Grayhill rotary switches. The 1% metal-film resistors on the Grayhill switches not only provide recallability, but also deliver a remarkable improvement in sound quality. Additional versions of the Variable MU Mastering Version include the M/S Mod, T-Bar Mod, and both the M/S Mod and T-Bar Mod.

Elop Limiter

The electro-optical, or Elop Limiter, excels on vocals and instrument tracking, but can also be used during the mixing process. The unit is based on the design of the LA-2A limiter, which uses a light source and photo-resistor to achieve gain reduction. Manley updated the design to incorporate an LED and provide less high-frequency roll-off at higher limiter settings. Its simple controls offer gain and reduction parameters. It also features a side-chain high pass filter with settings of 100 and 200 Hz.

Slam! Stereo Limiter and Mic Pre

The Slam! is the go-to box for getting LOUD! It is a veritable Swiss Army knife of audio, offering two microphone preamps with line level inputs, two Elop compressors, two FET limiters, and two DI inputs. Both the Elop compressor and FET limiter are available simultaneously and independently. Each adds a unique character to the sound, with the ability to dial-in the best of both. The Elop compressor is placed before the preamp, making it nearly impossible to clip the preamp stage. It also offers a dedicated side-chain high pass filter that is optimized for vocal de-essing. The FET circuit offers a variety of colors, from clean to grungy, all while maintaining “zero overshoot” limiting. There are dedicated side-chain inserts (send and return) for both the Elop and FET limiters. Three Slams are linkable, enabling six channels of limiting for 5.1 surround sound.

The Manley Slam! Mastering Version offers significant changes, compared to the original. The mic preamps and instruments have been removed, making way for paralleled tube sections, yielding lower noise and distortion. All pots have been replaced with rotary switches for detented recallability. The bypass switch offers ganged left and right controls and functions as a true hardwire bypass. This unit also features expanded ranges for the opto and FET limiters, and includes transformerless inputs. 

Combo Units

Voxbox Channel Strip

The Voxbox incorporates many of Manley’s technological innovations, including the preamp from the Mono Mic Pre, an Elop compressor, a Pultec style Mid EQ, and a dedicated Elop de-esser/limiter. The unit can be used as a single-input channel strip or can process two independent audio signals―one through the micreamp/compressor and the other through the EQ/de-esser. As the name implies, Voxbox is intended for vocal processing, but also excels at processing instruments. Many engineers employ two for stereo bus processing.


The Core channel strip is designed for the recording musician and offers exceptional value. Often referred to as the baby Voxbox, it includes the preamp from the Mono Mic Pre, Elop compressor, Baxandall shelf EQ with a sweepable mid frequency, and a FET “brickwall” limiter. The front panel features an intuitive layout for easy, quick adjustments. 


Reference Cardioid Microphone

The Reference Cardioid is a large diaphragm condenser microphone offering little coloration or perceivable sonic signature. Its liquid character and rich tonal balance make this microphone an excellent choice for recording drums, brass, guitars, and―especially―vocals. The 1" gold-sputtered diaphragm can withstand sound pressure levels of up to 150 dB, while the open-weave grille allows the capsule to capture a wide frequency spectrum. 

The proprietary suspension system attaches directly to the casing, while the capsule is mounted to a neoprene-rubber shockmount to prevent unwanted rumble from being recorded. This mic ships with a leather capsule cover and carrying case. 

Gold Reference

The Gold Reference is a multi-pattern large diaphragm condenser designed to capture truly accurate musical recordings. Like the Reference Cardioid, the Gold Reference uses a 1" gold-sputtered diaphragm capable of withstanding sound pressure levels of up to 150 dB and offers the same open weave grille to capture a wide frequency spectrum. The multi-pattern selection offers omni, cardioid, and figure-8, but with variable control to dial-in between each pattern. The Reference Gold is machined from brass and plated with 24-karat gold. The mic also features the same proprietary suspension system and capsule shockmount. 

The Gold Reference is also available as the Stereo Gold Reference, featuring two large diaphragm condensers. The lower capsule is rotatable through 90° for Mid/Side and XY coincident pair recording. 

Tube Mixers

16x2 Line Mixer

The 16x2 is a 16-channel summing mixer that offers professional-grade, large-format console performance in a 5U rack size. Each channel features combo Neutrik connections that accept both XLR and ¼" inputs and direct outputs. The master output section features transformer balanced XLR and transformerless ¼" outputs. The control panel features gain control, pan, aux send, solo, and mute for each channel. The master section offers main and monitor volume control with a switch to engage a second set of monitors. This mixer features large Sifam VU meters and a -15 dB dim switch.

The 16x2 also comes in a Mic version (16x2 Mic), which offers microphone preamps on each channel. This mixer offers many of the same features, but replaces the aux send with a mic preamp gain control. It also adds a phase-polarity switch and phantom power. Each channel also includes inserts to patch-in additional processors, such as compressors and equalizers.

The 16x2 (8+8) offers eight channels of microphone preamps and eight channels of line input channels with the same performance and specifications. 

The 16x2x4 is a 16-channel, line level summing mixer with four aux sends. Each channel features dual concentric pots with two toggle switches. The top toggle routes the signal to Aux 1, Aux 2, or both, while the lower toggle offers the same functionality, but for Aux 3, Aux 4, or both. 

The 16x2x4 (8+8) is a mic and line summing mixer offering eight channels of mic pres and eight channels of line level inputs. Four aux sends are available for the line channels. 

The 24x2 (16+8) is a 24-channel summing mixer featuring 16 microphone preamps and eight line input channels.

The 32x8 is a 32-channel line level summing mixer with four stereo buses.



The Backbone is designed to be the nerve center of a professional mastering setup. Featuring a comprehensive set of controls unique to a mastering engineer’s process, up to eight processors may be connected to the backbone. The send from the inserts is buffered for each processor, which prevents any lag when engaging an insert switch. Once pressed, the circuit connects the return, thereby allowing the processor to become active in the signal chain. There are a number of special functions available for the inserts, like sum/dif, insert 4 and 5 swap, and a mix fader between inserts 7 and 8. Insert 8’s is placed after the mix fader and output controls and is typically reserved for the last limiting stage. There are three sets of stereo inputs available to connect to your playback devices, with two sets of outputs for driving your monitors and master recorder. Other functions include left/right reverse, active/passive gain, left/right polarity reversal. The stereo controls for input and output gain are stepped for precision and recallability. There are two versions of the Backbone, the DB25, and the ELCO; both offer the same capabilities, but with different insert connections. 



The MicMAID was designed for auditioning combinations of four preamps and four microphones through a fast-acting matrix system. This unit features four inputs for microphones and preamps, while dedicated returns and direct outputs are offered for each mic pre. The font panel has four sections, instrument input, phase, routing matrix, and monitor control. 

The instrument input includes a ¼" DI for ground lift and through-output. There is also a ¼" fader input for real-time fader riding during the tracking process. The phase section offers a polarity switch, a variable phase control knob, and a range knob for shifting the frequency focus from low to full range. The matrix system selects up to 16 different combinations of four microphones and preamps. A lock button prevents any other mic or preamp from using the paired selection. The monitor section features a gain trim for matching levels of different combinations, which may be saved to any of nine user presets for instant recall. There is also a pickle remote featuring a momentary switch for cycling through presets. The MicMAID alleviates the time-consuming process of re-patching different recording setups to find the perfect combination quickly and efficiently. 


Manley Laboratories has elevated itself from humble beginnings to become one of the most respected manufacturers of professional audio equipment in the world. The company’s forward-thinking designs have raised the bar for what audio can and should be. Tubes rule, and so does Manley!

Add new comment

Was this an independent assessment by an objective reviewer . . . or a press release by the manufacturer themselves?

As the author of the article at B&H, I can assure you that this is an independent assessment of Manley and their products. My personal experience with their products has been excellent.     

  If David. Manley , ex South African, is with your company - please pass on this email ( and my email address ) to him.

  David is an old friend from Cape Town - and I would like to hi to him.

 I read this article on your fantastic equipment , linked from B&H - very impressive! 

 I just passed it onto to the sound studio and two composers that I work with .

Thank you,

 Ashley Lazarus.