Sound Pure's Take
The H2 Audio 2128 is an exceptional 500 Series mic preamp for engineers seeking real 1970s Helios console sound. Offering true Lustraphone transformer character, flexible dual-stage gain staging, and solid build quality, it is an indispensable front-end choice for tracking drum overheads, electric guitars, bass, and lead vocals.
From H2 Audio
The H2 Audio 2128 faithfully recreates the legendary 0011 mic preamp circuit that defined the sound of countless ‘70s rock records — now in a compact, modern format. With its punchy character, open top end, and fast transient response, the 2128 delivers the same musical warmth and headroom that made Helios the choice of Led Zeppelin, The Rolling Stones, and countless other icons.
This isn’t just vintage flavor — it’s the real Helios DNA, re-engineered for today’s studios. Whether you’re tracking vocals, drums, guitars, or bass, the 2128 adds that unmistakable analog presence that jumps out of the speakers. Complete with modern refinements like phantom power, phase reverse, selectable high-pass filter, and a transformer-balanced output with level control, the 2128 gives you legendary tone with modern flexibility.
What Makes It Legendary
- Faithful Helios DNA in 500-Series Form
- The 2128 brings the iconic preamp circuit from the Helios 0011 into your Lunchbox or rack, preserving the tonal essence that powered ‘70s British rock recordings.
- Ultra-Flexible Gain Staging
- Offers up to 70 dB of gain (25–75 dB in 5 dB increments) with a –20 dB pad—perfect for delicate vocals or driven drums and guitars.
- Transformative Input Stage
- Custom transformer design delivers rich harmonic depth and unmistakable Helios warmth right at the source.
- Performance-Ready Features
- Onboard 48 V phantom power, phase inversion, and selectable high-pass filter (0 Hz, 40 Hz, or 80 Hz) give you instant control over clarity and phase.
- Pro-Level Output Control
- Transformer-balanced output stage with integrated fader for up to +10 dB extra level control — more versatile than vintage modules ever were.
The 2128 packs the unmistakable punch, clarity, and open top end of the legendary Helios consoles into a compact 500-series module — ready to bring the golden era of rock to your rack.
- Gold plated audio toggle switches
- High-quality, ELMA gold plated rotary switches.
- Sealed, conductive plastic element pots
Rotary switches are all high-quality ELMA gold plated switches.
Toggle switches for audio are all gold plated.
Pot (output fader) has a conductive plastic element, sealed.
Power rail is +/-16V (32V total) giving higher output before clipping vs the original Helios 0011 preamp.
2128 Mic Preamp
- Mic Input
- Custom Lustraphone M10 input transformer providing 20dB of mic gain before the preamp.
Preamp
- 180/0 toggle switch
- inverts phase in 'up' position.
- PAD switch
- ~20dB pad
- FILTER toggle switch
- 0, 40 and 80Hz roll off.
- P48 switch
- 48V phantom power
- GAIN dB rotary switch
- 25 to 75dB of mic gain in 5dB increments.
- OUTPUT control
- output fader, allows distorted preamp effects while keeping nominal output level.
To the original 0011 preamp circuit (2128), H2 Audio has added a transformer balanced line output amplifier of original Helios design. 600 ohm drive capability up to 25dBm before clipping. Custom output transformer. The line output amplifier can add 10dB of gain after the mic preamp giving a total of 85dB of gain through the 2128.
Analog I/O connections
Standard 500 series input/output connections on rear edge connector.
Mechanical
- Height
- 5.25” (3U)
- Width
- 1.5”
Power source
Power is provided by 500 series rack.
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