Warm Audio WA-2MPX

A Modern Preamp That Revives the Golden Age of Tape Recording

The Warm Audio WA-MPX follows in the tradition of tube preamps derived from the early great tape machines that shaped studio sound aesthetics: a dense grain, "muscular" dynamics, and a typically vintage sense of depth. This signature, combined with a high operating voltage rated at 300 V and generous tube gain, has defined decades of recordings that have become benchmarks. With the WA-MPX, the goal is clear: to recapture that harmonic response and midrange presence that make "tape-like" takes so charming, while adapting it for everyday use in modern studios.

Within the Warm Audio lineup, the WA-MPX positions itself as a high-end tube mic preamp designed for those seeking a true sonic identity during tracking, but also as a coloration tool capable of adding character to stems, a bus, or even a finishing stage in mixing and mastering thanks to its selectable tape saturation.

Who the WA-MPX Is For: Recording, Reamping, Mixing, and Mastering

The WA-MPX targets demanding audio engineers, producers, and home studio users looking for a preamp with strong personality: vocals that naturally sit in the mix, thicker guitars, more "forward" snare drums, silkier overheads, or basses that gain authority without becoming harsh. Its gain reserve (up to 90 dB per channel) makes it a natural ally for low-sensitivity microphones, while retaining headroom to sculpt levels between input gain and output attenuation.

Thanks to its mic, line, and instrument inputs, it can also serve as a versatile front-end: direct recording of bass or synth, coloration of an already preamplified signal, or external processing during mixing. The built-in filters help achieve a clean, "ready-to-record" result without multiplying corrective steps in the DAW.

Key Features: From Clean Tube Tone to Full-On Saturation

True Tube Behavior, from Clean to Drive

Each channel is based on a 100% discrete hand-wired design and houses three tubes (two 12AX7s and one 12AU7 per channel). The WA-MPX allows switching from a surprisingly clear sound for quieter sources to richer saturation when pushing the tube stages. The balance between input gain and output level (attenuator) becomes a real creative lever: more drive and harmonics, or conversely more headroom and precision.

Essential Studio Controls + Two Vintage-Style Filters

Designed for session routine, the WA-MPX includes 48 V phantom power, polarity inversion, input impedance switching, and VU meter display to keep an eye on levels. The 80 Hz high-pass filter helps clean up vibrations, plosives, or hum, while the 2 kHz low-pass filter is ideal for taming excessive brightness and refocusing energy on the mids, in a distinctly vintage spirit.

"Tone," High Gain, and Tape Saturation: Three Ways to Define Color

The "Tone" control modifies the input transformer impedance to add extra analog color and a more pronounced sense of texture. The High Gain mode adds 20 dB (raising gain from 70 dB to 90 dB) to comfortably handle low-output microphones. Finally, the selectable tape saturation activates a discrete circuit in the signal path: natural compression, harmonic distortion, and focused filtering to evoke the behavior of a tape machine running at 15 IPS. Compared to a "full vintage" approach, this switchable saturation offers a real modern advantage: access tape spirit on demand, without relying on a tape recorder or tying up a complex chain.

Technical specifications

Number of channels	2	Valve	Yes
EQ	High-pass filter	Rack unit	2

Type	tube microphone preamp inspired by the tape recording era (351 style)	Selectable tape saturation	natural compression, harmonic distortion and 15 IPS tape recorder-style tonal filtering
Electronics	100% discrete, hand-wired	Low-pass filter	2 kHz
Input and output transformers	custom-wound CineMag USA transformers with large cores	Inputs	XLR microphone, TS instrument, TRS line
Specified operating voltage	300 V	Outputs	XLR line level, TRS line level
Gain per channel	up to 90 dB	Level indication	VU meter
High Gain mode	+20 dB (from 70 dB to 90 dB)	Frequency response	20 Hz to 20 kHz
Output attenuator	600 ohms	Power supply	internal IEC 115 V / 230 V
Per channel	2 x 12AX7 and 1 x 12AU7	Front panel	brushed aluminum
Number of tubes per channel	3	Chassis	steel
Microphone input	600-ohm transformer (6000 ohms nominal)	Knobs	vintage Bakelite-style
Microphone input with “Tone” engaged	150-ohm transformer (1500 ohms)