Warm Audio WA-MPX - microfoonvoorversterker

In a compact project studio, an engineer plugs a vintage ribbon microphone into the Warm Audio WA-MPX to capture a vocal take with the rich, harmonically complex character that only a true tube preamp can deliver. The WA-MPX is a single-channel, all-tube microphone and instrument preamplifier built around a 12AX7 and a 12AU7 vacuum tube, offering up to 70 dB of gain. It features custom-wound CineMag input and output transformers, switchable input impedance (600 or 150 ohms), a -20 dB pad, polarity reverse, an 80 Hz high-pass filter, and a tone switch that alters the input transformer impedance for subtle tonal shaping. A large VU meter provides clear output level monitoring, while the variable output control allows precise gain staging. The unit occupies a single 1U rack space and runs on standard IEC AC power with internal supply.

Key specifications

• Preamplifier type: Tube microphone preamplifier
• Number of channels: 1
• Vacuum tubes: 1x 12AX7, 1x 12AU7
• Maximum gain: 70 dB
• Microphone input impedance: 600 ohms (switchable to 150 ohms)
• Instrument input impedance: 2.2 M ohms
• Frequency response: 20 Hz – 20 kHz
• Phantom power: +48V
• Input connectors: 1x XLR (mic), 1x 1/4" TS (instrument)
• Output connectors: 1x XLR, 1x 1/4" TRS
• Pad: -20 dB
• Polarity reverse: Yes
• High-pass filter: 80 Hz
• Tone switch: Yes (changes input transformer impedance)
• Transformers: Custom-wound CineMag (input and output)
• Rack size: 1U
• VU meter: Yes

Why choose it

The WA-MPX brings the warmth and dimension of classic tube preamp design to your recordings. Its all-tube signal path with premium CineMag transformers delivers a smooth, musical character that flatters vocals, acoustic instruments, and electric guitars. The switchable impedance and tone switch allow you to tailor the response to different microphones and sources, while the high-pass filter and pad add flexibility in challenging recording situations. The large VU meter and variable output control ensure precise level management, making it an indispensable tool for any serious home or project studio.

Ideal use cases

• Recording vocals with condenser or ribbon microphones
• Adding tube warmth to acoustic guitar, bass, and other instruments
• Direct injection of electric guitar or bass for a rich, harmonically complex tone
• Overdubbing in a project studio where a single high-quality channel is sufficient
• Enhancing the sound of digital recordings with analog character

Good to know

The WA-MPX is designed for rack mounting in a standard 19" rack, occupying 1U of space. It operates on universal AC power (100-240V) via a standard IEC connector, with an internal power supply. The unit is built with high-quality components, including a robust steel chassis and premium connectors, ensuring reliable performance for years to come. Whether you are tracking a single source or building a high-end front end for your studio, the WA-MPX delivers professional results at an accessible price.