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CS566 | Processing Channel Strip


500 Units 2 4 6+
Discount -10% -15% -20%
CS566 | Line level sTUDIO cHANNEL sTRIP
Cs566 Saturation Channel Strip 4 Band Equaliser Hrk Fab

CS566 | The Ultimate Analog Swiss-Army Tool for Your Recording Studio

The CS566 is a top-tier analog studio processor, designed specifically for professional music producers and audio engineers. It’s the result of an extensive development process, with each stage of its circuitry meticulously fine-tuned to deliver a standout performance.

One of the key features of the CS566 is its independent +/-12dB input and output level controls. These allow for precise matching of source signal levels and the sensitivity of subsequent studio hardware in the signal chain, giving you complete control over your sound.

The CS566 is equipped with a Custom HRK VCA compressor, reminiscent of the classic discrete VCA modules from the ’70s and ’80s. This compressor offers comprehensive control over signal dynamics, ensuring a smooth and seamless operational experience.

In a groundbreaking design move, the HRK Solid State Drive Console Emulator revolutionizes the approach to analog saturation and harmonic generation. This, along with a four-band equalizer with dual frequency settings for each band, provides you with an unparalleled level of sound customization.

The CS566 also features an enhanced HRK Active Transformer. This adds the final touch to your sound, injecting additional harmonics and shaping the frequency response to mimic the classic transformer output stage.

Despite its extensive capabilities, the CS566 remains compact and user-friendly. It’s a complete line level channel strip that houses all the essential tools you need for recording, tracking, and mastering.

With the CS566, you have everything you need to create professional-quality sound.

CS566 Ed Thorn Review

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Custom HRK VCA Compressor – Real Alternative

Cs566 Vac Shop

The SSL G-Series console master bus compressor is the quintessential compressor originally found in the large SSL studio mixing desks.

The pioneering design of the G-SSL compressor was grounded on the dbx discrete transistor VCA modules, identifiable by their distinct black, silver, and gold casing.

Regrettably, the majority – about 99% – of modern G-SSL compressors are designed with the same VCA Integrated Circuits manufactured by THAT Corp., instead of the discrete transistor VCA modules. The use of these integrated circuits is a cost-effective solution for mass production in the current market.

Consequently, all contemporary G-SSL units and variants are constructed using the same VCA-compressor integrated circuit.

HRK has developed a custom hybrid discrete version of the VCA block, fabricated with New-Old-Stock (NOS) Military Grade transistors from the ’80s. The HRK design isn’t a replication of the dbx module, but rather a proprietary design by Bart Hrk.

Each CS566 VCA compressor is hand-assembled using these NOS military-grade transistors from the ’80s. They bear similarities to the original dbx modules found in the vintage SSL compressors, which were also composed of discrete transistors.

As a result, the HRK VCA Compressor delivers a tonal quality akin to that of the iconic compressors of the ’80s, thanks to its custom design and authentic NOS discrete transistors.

CS566 Overview Video

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Solid State Drive | Console Emulator


The HRK Solid State Drive is a studio console emulator that generates distinct harmonics typical of a large format mixing desk. This proprietary design concept was innovatively developed by Bart Hrk.

The Solid State Drive is far from a conventional overdrive or saturation circuit found in most analog saturation studio equipment. Its design stands unique and distinctively apart from popular products in the market.

Harmonics produced by the Console Emulator block are smooth and subtle, yet noticeably present. The Console Emulator maintains the integrity of the soundtrack, ensuring the intended character is not obscured or compromised.

The Solid State Drive is the culmination of a lengthy development process, aiming to replicate the experience of a studio recording console.

For optimal results in tracking, mastering, or any other studio application, it is recommended to use the Solid State Drive and the VCA Compressor in tandem.

CS566 vs SSL SiX Channel | Comparison

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HRK Blue EQ | Four-Band, Smooth, and Musical Equalizer

Cs566 Blue Eq Hrk1

The CS566 features a four-band, ultra-smooth Blue EQ equalizer. Each band provides two selectable frequency settings and a boost/cut range of +/-12dB.

Every band is constructed around a separate operational amplifier, creating an independent circuit section. This arrangement minimizes undesirable interaction between the EQ bands.

The separation of equalizer bands significantly curbs the boost/cut interplay between bands and mitigates the cross-influence of EQ sections’ center frequencies.

Uniquely designed, the HRK Blue EQ is a non-invasive and smooth equalizer created specifically as a versatile sound editing tool. It maintains a respectful approach towards the original signal character, without imposing a harsh tonal shift.

The chosen frequencies cater to a wide range of studio applications. The high frequency (HF) and low frequency (LF) bands are shelf-type filters, engineered for easy adjustment with gentle, musical curves.

The mid-low (ML) and mid-high (MH) bands are bell-type filters, delivering progressive and smooth characteristics. They offer signal correction without pitch-ringing, even at higher boost levels.

The Blue EQ is a transparent equalizer, providing substantial processing capabilities while remaining intuitive and user-friendly.

With the HRK Blue EQ, you simply can’t go wrong!

Augmented HRK Active Transformer

Hrk Active Transformer

The Augmented Active Transformer generates greater saturation and harmonics compared to a standard Active Transformer, making it a fitting choice for the final stage of the CS566 Channel Strip.

Bart Hrk pioneered a proprietary design for an Active Transformer to counter the challenges associated with common passive transformers.

Passive transformers often face susceptibility to electromagnetic interferences, such as 50Hz Hum and RF Smog. Additionally, their frequency response hinges on load and source impedance, which can detrimentally affect the overall performance of analog studio equipment.

In contrast, the HRK Active Transformer produces authentic sound, including the harmonic content and tonal response of an audio transformer, while eliminating all the issues associated typically with passive transformers.

The Active Transformer subtly creates an “Air” effect and ensures extended low-frequency performance.

The saturation of the Active Transformer is determined by the output level. A higher output signal will cause the Active Transformer to saturate more, reminiscent of classic studio equipment.

Stereo Buss Operation

The CS566 is designed for the stereo bus processing.

The VCA Compressor sections can be coupled with the supplied linking cable to control the stereo image of the processed signal.

Cs566 Saturation Channel Strip 4 Band Equaliser Hrk Stereo Bus Processing

*The Stereo Link cable is provided together with a pair of the CS566.

Compressors Comparison Video

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Customers Reviews

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CS566 Specification

Input Type / Input Impedance Balanced Electronic 20k
Input Level Control Range +/-12dB
Output Type / Output Impedance Balanced HRK Active Transformer Less than 10R
Output Level Control Range +/-12dB (The output level works as Gain Make-up)
Initial Gain 0dB Input and Output Level Control set to 0dB
Max Output Level +25dBu@0.1%THD with 1k Load * Balanced Signal
Recommended Load Balanced 10k Minimum Supported Load 600R
Phase Reverse No CS566 is not introducing Phase reverse in any mode of operation.
Frequency Response 5Hz-80kHz@-1dBr Compressor and EQ disengaged.
Static Noise Level -95dBu@10Hz-22kHz Compressor and EQ disengaged.
Power Consumption Typically 45mA per unit 60mA max. per unit
Format API 500 Format Compatible with most of the 500 Racks
Type of Compressor Engine VCA coupled with Discrete Operational Amplifier
Compression Curve Adaptive Soft-Knee Threshold and Ratio depends on Compress Knob Setting (1)
Threshold Range -25dB / - 20dB
Ratio Range vs the Ratio Switch 2:1 - 3:1 / 4:1 - 6:1 Ratio switch changes the range of Compression ratio (2)
Attack Slow/Fast Switch 30mS/400uS The Attack Switch changes the attack time
Side Chain HPF 160Hz@6dB/oct Use the HPF Switch
Recovery Time 50mS - 2.5S
Phase Reverse No CS566 is not introducing Phase reverse in any mode of operation.
Frequency Response 5Hz-20kHz@-1dBr Compressor and EQ disengaged.
Static Noise Level -85dBu@10Hz-22kHz

1- The Compress knob controls the threshold and ratio of the compression. Turning the Compress knob toward MAX will increase compression ration and threshold.
2- The Ratio switch changes the range of the ration controlled by the Compress knob.
Number of Bands 4 Bands Independent Circuitry Section per Band
Frequencies per Band 2 Selected with Switch
Boost/Cut Range +/-12dB
HF 12kHz/8kHz Shelf
HM 4.8kHz/2.6kHz Bell
LM 1.2kHz/400Hz Bell
LF 80Hz/160Hz Shelf
Phase Reverse No CS566 is not introducing Phase reverse in any mode of operation.
Frequency Response 5Hz-80kHz@-1dBr Compressor and EQ disengaged.
Static Noise Level -90dBu@10Hz-22kHz
Additional Notes
The CS566 is a line-level channels strip. The CS566 is not equipped with a microphone preamplifier.

The input signal should be connected to the rear XLR input.

It is recommended to use -12dB input signal level initially and increase the level signal if required.
ALL HRK Products Are Brand New - Assembled and Fully Tested

All HRK Products are tested with the industry’s best audio measuring equipment – The Audio Precision

Audio Precision is an industry leader in providing high-quality audio testing equipment. They are renowned for their test systems’ precision, reliability, and versatility.

When testing studio audio devices, Audio Precision’s equipment can assess parameters like frequency response, harmonic distortion, intermodulation distortion, phase response, signal-to-noise ratio, and cross talk. In-depth and accurate testing allows the identification of even the smallest issues in audio quality, enabling corrections and improvements that can significantly elevate the overall product quality.

In conclusion, using Audio Precision test equipment is an excellent way to ensure that all HRK products are performing at their best, meeting the standards required for the Professional Studio Applications.


Stereo Buss Operation

All Items are dispatched from Poland in the European Union within 1-3 working days.

Country / RegionShipping CostCustoms FeeVAT
All 27 European Union Countries – Delivery Time: 2-7 Days

– 14.99USD for orders below 299USD

– FREE shipping for orders over 299USD

NO Customs Fees– Yes, for personal orders- Not charged with the EU VAT number
United Kingdom – Delivery Time: 3-7 Days

– 14.99USD for orders below 299USD

– FREE shipping for orders over 299USD

No VAT ChargeHMRC collects the VAT or additional Fees if applicable.
USA, Canada – Delivery Time: 5-10 Days

– 14.99USD for orders below 299USD

– FREE shipping for orders over 299USD

NO Customs Fees for orders up to 800USD – charged by the USA Customs OfficeNo VAT charge.
Australia, Japan, South Korea –  Delivery Time: 5-14 Days

– 19.99USD for orders below 299USD

– FREE shipping for orders over 299USD

There is no info available – refer to local regulations.No VAT charge.
Switzerland Delivery Time: 3-7 Days

– 14.99USD for orders below 299USD

– FREE shipping for orders over 299USD

There is no info available – refer to local regulations.No VAT charge.
Norway Delivery Time: 3-7 Days

– 14.99USD for orders below 299USD

– FREE shipping for orders over 299USD

There is no info available – refer to local regulations.No VAT charge.
Worldwide Destination Delivery Time: 3-14 Days– 29.99USDRefer to local regulations.No VAT charge.

EU Customers

EU Customers will not pay any extra customs fees.

Business customers with a valid EU VAT number will not have to pay VAT tax.

Please enter your EU VAT Number at checkout and the VAT will be deducted from the Total Payment. The VAT number is automatically checked in the VIES database.

For personal orders from the EU, VAT will be added at checkout.

UK Custmers

We ship directly to United Kingdom.

UK VAT tax is collected by HRMC

Non-EU Customers

Customers from outside the EU purchase items with no VAT.

Please select the destination country and the VAT will be removed automatically.

If the VAT is not removed, please email customer service via the contact form and a custom invoice will be issued.

USA and Canada

Orders from the USA below 800USD are FREE from customs tax.

We ship directly to the USA and Canada

Payment Options:

You can pay for your order with any Credit Card or Apple Pay!

PayPal – We do not use PayPal as a payment method.

7 Days Return Policy

Our return policy is a part of the general Terms & Conditions, which you must acknowledge at the checkout. We stand by fair rules and a win-win approach.
We understand that our customers may wish to return the product and we provide such an option.
However, because we are a small company, we can’t afford to run a grade B outlet shop like big distributors and provide a 30 day return period. We can’t also scrap every returned unit.
We can charge our customers more to offset the cost of the returns, and this is what major distributors do. Or we can keep our prices low and hope that our customers will appreciate our policy.
This is why we provide the 7 days test period after receiving the package with the ordered items. If you wish to return the item, we will accept the return request, provided that the item is not damaged.

If the item is damaged during transport, we will do our best to help you and provide a replacement product.