Warm Audio MPX Dual-Channel Tape-Era Tube Mic Preamp (Ampex 351 Clone)

Born from the legendary tape machine preamps that shaped rock ‘n’ roll history, the WA–MPX brings authentic vintage warmth to modern studios with an impressive 300v of raw power and up to 90dB of tube gain. This faithful reproduction captures the signature sound that defined hit recordings from Elvis Presley, Bing Crosby, Les Paul, Nat King Cole, and Roy Orbison during the golden era of tape recording. The original 351–style tube preamp became the king of studio technology, creating a timeless sound that elite audio engineers continue to pursue today.

Each WA–MPX features hand–wired construction with 100% discrete electronics and three tubes per channel that generate incredible gain when the high–gain switch is engaged. Custom–wound, large–core CineMag transformers handle both inputs and outputs, bringing each preamp circuit to 300v operation. The steel chassis houses a brushed aluminium faceplate, vintage–style bakelite knobs, and amber–tinted VU meters, with every unit carefully hand–inspected and tested at Warm Audio’s Austin, Texas headquarters.

Professional features include input impedance switching, +48v phantom power, polarity inversion, and comprehensive input/output gain controls. The 80Hz hi–pass filter tames unwanted bass frequencies, while the 2kHz low–pass filter shaves excess highs for a more vintage tone profile. The classic Warm Audio “tone” control alters input transformer impedance for additional analogue colour, and the high gain control adds an extra 20dB of tube gain – particularly useful with lower output dynamic and ribbon microphones. The Tape Saturation control engages a discrete circuit that adds natural compression, harmonic distortion, and focused tone filtering to emulate tape machines running at 15IPS, providing just enough imperfection for mixing and mastering applications.