Store demo unit with minor cosmetic marks.

The Warm Audio WA-251 is an all-vacuum-tube, large-diaphragm, transformer-balanced condenser microphone based on the classic ELA M 251. It uses a custom all-brass CK12-style capsule, a JJ 12AY7 vacuum tube, and a CineMag USA output transformer paired with WIMA, Solen, and polystyrene capacitors. Three polar patterns are selectable from the external power supply. The WA-251 is known for its controlled bass (with a built-in roll-off below 50 Hz), present midrange, and a smooth 5-10 kHz dip in cardioid mode that tames harshness on vocals, acoustic guitars, and other acoustic sources.

The built-in 50 Hz high-pass characteristic keeps the WA-251's low end tight in the mix rather than muddy or boomy. With most usable bass frequencies running from 60 to 250 Hz, the WA-251 captures lows and mids with definition. In cardioid mode, the 5-10 kHz dip smooths out the high end, making it forgiving on sibilant vocalists and bright acoustic instruments. This frequency shaping is inherent to the capsule and circuit design, not a switchable filter, giving the WA-251 its signature sound from the moment it is plugged in.

The CK12-style capsule, JJ 12AY7 tube, and CineMag USA transformer work together to deliver the warm, balanced tone that made the original 251-style microphone one of the most sought-after studio tools ever produced. Three polar patterns (cardioid, omnidirectional, and figure-8) provide flexibility for different recording setups and room acoustics.

Specifications

• Type: Tube condenser
• Capsule: WA-12-B-60V, edge-terminated, dual-backplate, all-brass CK12-style
• Tube: JJ Slovak 12AY7
• Transformer: CineMag USA
• Polar patterns: Cardioid, omnidirectional, figure-8
• Frequency response: 20 Hz to 20 kHz
• Max SPL: 132 dB (<0.5% THD)
• Output impedance: 200 Ohms
• Self-noise: 12 dBA
• S/N ratio: 80 dBA
• Dynamic range: 125 dBA
• Cable: Gotham 5 m GAC-7, 7-pin
• Mic dimensions: 247 x 46 mm (9.72" x 1.81")
• Total weight: 5.44 kg (12 lb) including PSU, shockmount, and cables

In the Box

• WA-251 microphone
• External power supply with IEC cable
• Shockmount
• Gotham 5 m 7-pin GAC-7 cable
• Wood storage box