Heiserman Audio has announced the Type-21, a new large-diaphragm condenser microphone debuting at NAMM 2026. The Type-21 is positioned as a compact, phantom-powered condenser designed to deliver a sound character inspired by classic ELA M 251-style microphones, while offering modern features and a smaller physical footprint suited to contemporary studio workflows.
Design and concept
At the center of the Type-21 is Heiserman’s Generation 5 HK12 capsule, the same capsule used in the company’s H251 microphone. The capsule is hand-crafted in the United States and housed in a compact, all-aluminum body. Unlike traditional tube-based 251 designs, the Type-21 uses a transformerless circuit built around a low-noise JFET, along with selected resistors and capacitors intended to prioritize low noise and consistency.
The smaller form factor is designed to make placement easier in tighter recording environments, such as drum rooms, guitar cabinets, and vocal booths, where larger vintage-style microphones may be less practical.
Controls and functionality
The Type-21 includes onboard controls aimed at flexibility during tracking. Engineers can switch between cardioid, omni, and figure-8 polar patterns, engage a high-pass filter to reduce low-frequency buildup, or activate a -15 dB pad for higher-SPL sources. The microphone operates on standard +48 V phantom power via XLR, eliminating the need for an external power supply.
A softly illuminated Heiserman logo is integrated into the microphone’s circuitry, serving as a visual indicator that the microphone is powered and active.
Manufacturing and build
Heiserman Audio states that the Type-21 is designed, machined, assembled, and manufactured entirely in the United States. The microphone is intended to balance studio use with durability suitable for regular session work.
Key features
- Generation 5 HK12 large-diaphragm capsule
- Transformerless JFET condenser design
- Switchable cardioid, omni, and figure-8 polar patterns
- High-pass filter and -15 dB pad
- Phantom-powered operation
- Made in the USA
Technical specifications
- Type: Large-diaphragm condenser
- Capsule: Generation 5 HK12, brass and acrylic chambered
- Diaphragm: Dual 6-micron, 24k gold-sputtered Mylar (PET)
- Power: +48 V phantom power
- Frequency response: 20 Hz – 20 kHz
- Max SPL: 130 dB (145 dB with pad)
- Sensitivity: 20 mV/Pa ±1 dB
- THD: <0.5% @ 1 kHz, 1 Pa
- Output impedance: 42 Ω
- Amplifier type: FET
- High-pass filter: 160 Hz
- Connector: Amphenol XLR
- Mount: Standard 57-style mic clip
- Dimensions: 138 mm (L) × 50 mm (W) × 28.5 mm (D)
Availability and pricing
The Heiserman Audio Type-21 is scheduled to be available starting January 15, with a suggested price of $1,499 USD. It will be sold through authorized Heiserman dealers worldwide as well as directly from the manufacturer.
