Heritage Audio HA-81A EQ | Classic analog channel strip combining a 73-style preamp with an 81A four-band EQ
The HA-81A EQ integrates a classic 73-style fully discrete preamp with an 81A-style four-band equalizer into a 1U chassis, continuing the British sound’s thickness, warmth, and relaxed dynamics. It also features high-pass/low-pass filters and essential recording controls, allowing precise spectral shaping from vocals and electric guitar to close-recorded drums, meeting professional recording and mixing needs.
Key Product Features
- Classic 73-style fully discrete Class A microphone preamp, delivering a thick, warm British tone
- 81A-style four-band EQ: switchable low/high band architecture, dual mid bands, stepped frequency points
- Independent high-pass and low-pass filters for quickly taming low-end rumble and ultra-high-frequency harshness
- Carnhill UK input/output transformers, preserving classic transformer character and natural dynamic compression
- Supports microphone, line, and front-panel Hi‑Z direct input, covering a wide range of sources
- Recording essentials including 48V phantom power, PAD, and phase invert switches
- EQ independent bypass for easy A/B comparison and quick return to the original sound
- Stepped knobs with precise markings for recall and consistency across sessions
- 1U 19-inch rack size with internal universal power supply, easy to integrate into various studio setups
Specifications
| Brand / Model | Heritage Audio HA-81A EQ |
| Product Type | Analog channel strip (mic preamp + 4-band EQ) |
| Preamp Architecture | Fully discrete Class A, transformer-balanced design |
| Transformers | Carnhill (input/output) |
| Mic Gain | High-gain design, suitable for dynamic and ribbon microphones (see official specs) |
| Phantom Power | 48V switchable |
| PAD | Switchable PAD (see official specs) |
| Phase Reverse | Yes |
| Direct Input | Front-panel Hi‑Z DI (1/4" TS) |
| Line Input | Balanced Line In (XLR, per official configuration) |
| Equalizer | 81A-style 4-band: switchable low/high bands, dual mid bands, stepped frequencies, selectable high Q (per official design) |
| Filters | High-pass and low-pass filters with selectable frequency points |
| Bypass | EQ section bypass; allows quick A/B comparison |
| Output | Balanced XLR output |
| Indicators | Output level / peak indicators (per official configuration) |
| Frequency Response | Wideband, low-distortion design (see official specs) |
| Maximum Output | Professional-level high headroom (see official specs) |
| Power | Internal universal power supply 100–240 VAC, 50/60 Hz |
| Dimensions | 1U 19-inch rack |
| Weight | Refer to official specifications |
