HRK EQ556 | SIX BAND PARALLEL EQUALISER 2025 - NEW

U.S. Import & Tariff Notice for American Buyers

No Section 232 Tariffs Apply / Composite Front Panel

• Zero Aluminum / Composite Front Panel: Please note that the front panel of this API 500-series module is made entirely from a high-grade composite material—it contains no aluminum. As such, this item does not contain aluminum subject to Section 232 tariffs or additional import surcharges when entering the United States from Europe.
• Open-Frame Construction (No Metal Chassis): This unit features an open-frame design consisting solely of the PCB and internal components, without any external steel or aluminum enclosure. It contains no bulk metals that fall under U.S. metal tariff regulations.
• Private Sale Declaration: This item is being sold by a private individual for personal/used gear resale.

U.S. buyers can purchase with confidence knowing this module is exempt from steel/aluminum tariff classifications.

The texture of pure sound

There is a specific weight to audio that most digital tools simply cannot replicate. It is not just something you hear; it is a resonance you feel in the room, a depth that makes a recording feel physical and alive. When you engage the EQ556, you aren't merely adjusting frequencies—you are sculpting the very air within your studio. Imagine the shimmer of a high-end vocal or the controlled, heavy punch of a kick drum, all achieved with a smoothness that feels natural, never forced. This is the tactile sensation of true analog precision.

A definitive standard for your signal chain

For those who have moved past "good enough" and now demand an absolute standard of excellence, the EQ556 exists. This is not a tool for casual listening; it is a piece of archival-grade equipment designed for the professional engineer who views their studio as a sanctuary of sound. By acquiring this six-band parallel equaliser, you are claiming more than just hardware—you are claiming a level of sonic provenance that defines a master's workspace. It is an extension of your creative identity, ensuring that every decision you make is backed by unrivaled accuracy and musicality.

A vanishing opportunity

As the HRK Shop moves toward its final chapter, the availability of these precision instruments is reaching its end. This is not a revolving stock; it is a terminal event. Because we utilize specialized, high-quality selected components and our custom HRK active transformers, once this current production run is claimed, it is gone. We are entering a period of extinction for this specific hardware. As you observe others securing their place in audio history, you will realize that hesitation leads to the most expensive mistake in engineering: the regret of a missed opportunity.

The final resolution

As you recognize the profound impact this equaliser will have on your mixes, you will find that securing this unit is the only logical way to complete your studio's potential. Allow yourself the luxury of uncompromising control. When you integrate the EQ556 into your workflow, you will experience the immediate satisfaction of hearing your tracks with absolute clarity and depth for the first time.

Technical Specifications

Precision Engineering & Architecture

• Innovative Parallel Filter Design: A breakthrough architecture ensuring a coherent phase response across the entire spectrum, delivering transparent, uncoloured audio.
• Six Independent Bands: Complete control over your sonic landscape with six discrete bands of equalisation.
• Selectable Frequency Precision: Each band features two distinct frequency settings to allow for meticulous sculpting.
• Discrete Signal Path: Each band is powered by its own separate discrete opamp for maximum isolation and clarity.
• Custom HRK Active Transformer: Coupled with our signature transformer design for superior harmonic character and stability.

Operational Parameters

• Boost/Cut Range: Precise +/-9dB control across all bands (Nominal Gain: 0dB at 12 o'clock).
• Filter Types: LF Shelf, Bell, Bell, Bell, Bell, HF Shelf.
• Frequency Selection: 80Hz/160Hz, 120Hz/330Hz, 660Hz/1.2kHz, 2.6kHz/4.8kHz, 6kHz/10kHz, 12kHz/16kHz.

Audio Performance & Connectivity

• Typical THD+N: Less than 0.02% @ 1k in 10Hz-22kHz BW.
• Noise Floor (EQ Engaged): Less than -90dBu @ 10Hz-22kHz BW.
• Bandwidth at Flat Response: 10Hz - 60kHz @ -1dB.
• Maximum Output Level: +25dBu @ 0.1% THD.
• Input Impedance: 20kΩ (Balanced).
• Output Impedance: Less than 50Ω (Balanced Active Transformer Output).

Physical & Power Requirements

• Format: Standard 500 Rack compatible.
• Power Consumption: Less than 60mA.
• On-Board Voltage: Features 500 Rack PSU filters for pristine power delivery.