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SM2558 Active Stereo Summing Mixer

Original price was: zł1,563.Current price is: zł1,446.

  • Mix and Match HRK 500 Products!
500 Units 2 4 6
Discount -10% -15% -20%

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SM2558 | Active Stereo Discrete 10 Inputs 500 Summing Mixer

SM2558 | Fully Featured Stereo Summing Mixer

The SM2558 redefines Out of The Box stereo summing in a sleek, 500-series compatible unit.

With 10 active balanced inputs, it empowers your mixes with unparalleled clarity in the pure analog domain.

Experience zero-latency direct monitoring for an intuitive, efficient workflow.

Equipped with API Style discrete operational amplifiers and NOS transistors, it ensures exceptional signal summing quality.

Outputs are enhanced with custom Augmented HRK Active Transformers to deliver Classic Analog Sound.

Flexible routing and a Vintage Drive offer creative mixing options, adding warmth and depth.

Available directly from HRK Shop, the SM2558 combines professional-grade features with outstanding value, making high-end mixing accessible.

The Easy Way to Use SM2558 Only with Two Outputs Interface

The SM2558 can be used even with stereo or two outputs audio interface.

You don’t need to wait until you’ll upgrade to a multi-outputs interface to benefit from the Analog Vintage Sound of the SM2558 Summing Mixer.

The SM2558 can be used as a Mastering Tool for a Stereo Mix. If a stereo signal is sent to the front panel Stereo Inputs, it will be enhanced by the analog circuitry and added harmonics content.

This simple process will upscale your music production eve if you are less experienced in Audio Engineering or not yet equipped in an expensive studio gear.

Discrete Operational Amplifiers Summing Bus

The analogue summing of all 10 inputs is processed with the Class A Discrete Operational Amplifiers.

The Opamps used in the SM2558 are inspired by the famous British design from the ’70s.

The SM2558 Discrete Opamps are made with selected NOS components.

The Vintage Drive Mode

The Vintage Drive Mode is designed to emulate the characteristic sound of vintage mixing consoles by adding harmonics through the saturation of the Discrete Circuitry.

This feature enriches the signal without overdriving the output transformers, next in the signal chain device, such as Audio Interface.

This approach ensures the high fidelity of the mix, maintains equal signal levels, and avoids digital clipping.

The result is a mix enhanced with even harmonics, bringing out a richer bottom-end, creating space between mix elements, and producing a more vivid sound scene.

Engaging the Vintage Drive is made simple with a switch located on the front panel, allowing for easy access to this classic sound enhancement.

Using the 500 Single Slot in a Stereo Configuration Arrangement

Utilizing a single slot in the 500 rack for stereo mode might seem unconventional, yet it is entirely feasible and safe.

The XLR input connector on the 500 rack’s rear panel functions as a direct connection from the XLR socket to the module’s PCB edge connector, making it simple to convert to an output using the provided XLR male-to-male adapter.

The arrangement for this setup is illustrated below, demonstrating how the rear panel XLR connectors can be adapted.

The necessary XLR male-to-male adapter comes included with the SM2558.

It’s important to note that if your 500 rack includes any additional routing features, these should be disabled to ensure the proper operation of the SM2558.

User Manual – Read before using the SM2558:

SM2558 User Manual

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.