Product Description
DOPA520 Discrete Opamp | The Ultimate Mastering Colour Module!
- Inspired by Famous Classic USA Opamp Design
- Designed for Professional
- Mastering Adds Harmonics and Space
- Enhances Details and Glues the Mix!
- Makes the Sound more Live and Vivid
- Made with High Quality Discrete Components
- NOS Silicon Transistors in the Input Stage
- On-Board Voltage Regulators
- Compatible with DIYRE Colour Format
The DOPA520 has a unique ability to enhance any audio signal by highlighting the details, amplifying the harmonics and adding space to the track.
The main use of the DOPA520 is the Mastering of the finished Mix when used in the mix bus section.
The DOPA520 can be used during the recording. Any signal source, instrument or vocal will benefit from the unique qualities of the DOPA520.
The DOPA520 will enhance the effect of any other Colour Module installed in the signal chain. Mastering Colour Bundles with DOPA520 are available at the discounted price.
The DOPA520 does not introduce any gain nor the phase shift and does not change the frequency response. It works its magic thanks to the unique design and selection of high-quality components!
High-Performance Discrete Operational Amplifier
The DOPA520 is a Studio Grade Discrete Operational Amplifier Colour Module made with selected high-quality components.
The design of DOPA520 was inspired by classic Discrete Opamp designed in the USA. The design was optimized for Mastering purposes and to achieve superior audio performance.
The DOPA520 is using Vintage Silicon transistors in the input stage. This is another reason why the DOPA520 delivers outstanding tone-shaping results.
The interferences from the 500 rack switch mode power supply may become the real problem for professional studio applications.
The On-Board Voltage Regulators ensures the ideal operating conditions and filter-out any residual harmonics and interferences from the 500 Rack PSU.
HD Audio Samples
Club Track Dry
Club Track DOPA520
Club Track 2 Dry
Club Track 2 DOPA520
Electric Guitar Dry
Electric Guitar DOPA520
Acoustic Guitar Dry
Acoustic Guitar DOPA520
Disco Track Dry
Disco Track DOPA520
Jazz Track Dry
Jazz Track DOPA520
Female Vocal Dry
Female Vocal DOPA520
Male Vocal Dry
Male Vocal DOPA520
Club Track Dry
Club Track Discrete Saturation + DOPA520
Club Track 2 Dry
Club Track 2 Discrete Saturation + DOPA520
Electric Guitar Dry
Electric Guitar Discrete Saturation + DOPA520
Jazz Track Dry
Jazz Track Discrete Saturation + DOPA520
Female Vocal Dry
Female Vocal Discrete Saturation + DOPA520
Club Track Dry
Club Track British Console + DOPA520
Club Track 2 Dry
Club Track 2 British Console + DOPA520
Electric Guitar Dry
Electric Guitar British Console + DOPA520
Country Dry
Country British Console + DOPA520
Jazz Track Dry
Jazz Track British Console + DOPA520
Female Vocal Dry
Female Vocal British Console + DOPA520
Brand New, Assembled and Tested.
Every single HRK product is carefully tested with Audio Precision test equipment before the shipping to ensure hassle-free operation.
Shipping
All Items are dispatched from the European Union within 1-3 working days.
We offer Fast & Free Worldwide UPS shipping with tracking.

FREE delivery is available for orders over the 249USD to EU, USA and Canada.
Total cart value / Delivery cost:
up to 99USD / Delivery Cost – 19.99USD
99 – 148USD / Delivery Cost – 14.99USD
149 – 248USD / Delivery Cost – 9.99USD
over 249USD – FREE Delivery
FREE delivery is available for orders over the 299USD to Australia, New Zeland, Japan and other destinations.
Total cart value / Delivery cost:
up to 148USD / Delivery Cost – 19.99USD
149 – 298USD / Delivery Cost – 14.99USD
over 299USD – FREE Delivery
Please check the shipping cost during the checkout.
Delivery to other WorldWide destinations – 24.99USD
VAT and Customs Fees
For non-business orders from the EU, the VAT will be added at the checkout.
VAT is removed automatically for orders from outside the EU.
No Custom Fees for EU Customers.
Orders from the USA below 800USD are customs tax free.
EU Business Customers
If you have the EU VAT number you can purchase the products available in the Bart HRK Shop with no VAT Tax.
Please enter your EU VAT Number at the checkout and the VAT will be deducted from the Total Payment.
The VAT number is automatically checked in the VIES database.
Non-EU Customers
Customers from outside the EU can purchase the 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 custom invoice will be issued.
Orders from the USA below 800USD are customs tax-free.
Payment Options:


You can pay for your order with any Credit Card!
Our return policy is a part of the general Terms & Condition which you have to acknowledge at the checkout.
We stand for fair rules and a win-win approach. We understand that our customers may wish to return the product and we do provide such option. However, because we are a small company we can’t afford to run a grade B outlet shop like big distributors and provide the 30 days return period.
We can’t also scrap every returned unit. We could charge our customers more to offset the cost of the returns, 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 and if you wish to return the item we will accept the return request, providing that the item is not damaged and we can resell the product with the minimal loss for the company.
If the item is damaged during the transport we will do our best to help you and provide the replacement product.