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Raising the Standard

CXA81 Mk II

Can you summarise the original vision behind the CXA81 and how it paved the way for Mk II? What aspects of the original CXA81's legacy did you want to preserve or enhance? 

"CXA81 has evolved, developed, and improved as a product for many years through various models, even as far back as 650A to 651A, with an extensive redesign for CXA80. CXA81 has become a multi-award winning product, winning the What Hi-Fi? Best Buy award for four consecutive years.  

 

At every stage in the CXA81 Mk II design process, we were aware that the CXA81 sound had been extremely well received, so we didn't want to move too far away from this signature sound, which we believe to be fun, dynamic, engaging, and exciting. Our main goal was to add an extra level of definition to the current signature sound rather than a major deviation."

CXA81 Mk II next to a mixing desk

The Mission

 

What were the main objectives for CXA81 Mk II from an engineering perspective? How did the team challenge the status quo in amplifier design? 

"CXA81 has established itself as a great-sounding, fully-featured product, so the engineering team had one clear mission: How do we make this best-in-category product even better?

 

With such a strong starting point in CXA81, it didn't seem wise to completely redesign a great product. Instead, we decided to squeeze every last drop of performance from an amplifier at this price point. It sounds simple enough, but it was anything but! One of our engineering team members described this as a sculptor chipping away at an existing statue to reveal a new level of detail rather than starting from the ground up. "

Inside the CXA81 Mk II

 

Can you walk us through the most significant technical upgrades in CXA81 Mk II? How do these upgrades translate into improved sound quality for the listener? 

Can you walk us through the most significant technical upgrades in CXA81 Mk II? How do these upgrades translate into improved sound quality for the listener?

 

The most obvious specification improvement was to upgrade the ESS Digital to Analogue Converter (DAC) from the ESS Sabre ES9016K2M to the ES9018K2M. Upgrading the DAC gave us noticeable improvements in performance, but we were confident there was more to come.

 

The main work on CXA81 Mk II was component tuning, divided into three sections: understand, improve, and refine.

 

Firstly, we had to understand the exact areas of the PCB layout that affect sound quality and determine the influence of each component. This was a painstaking task, following the full signal path and swapping in and out components to fully appreciate their effect on overall performance. For every step, we listened to the changes made and documented their impact. Only with this understanding could we move to the improvement stage. 

 

Initially, the next stage focused on areas with the most significant effect on performance, switching between combinations of components from multiple suppliers. It is not enough to optimise one component at a time, as the interactions within different permutations can sometimes produce unexpected results (not all positive). It was an iterative process, taking months of meticulous work across many listening sessions. This phase of work resulted in five unique variants of tuned prototypes.

 

The third and final phase was to listen in depth to the five differing builds of units, using the CXA81 as the reference in each case. Three units were soon discarded, leaving two units, which our listening panel agreed, delivered on our mission – to build on the strengths of the CXA81 while providing another level of detail and a more expansive soundstage. There was a further round of mixing and matching to take the best elements of these two prototypes, resulting in the CXA81 Mk II tuning you hear today. 

Man setting up the volume on the CXA81 Mk II

Test Tracks

 

What specific tracks or types of music were pivotal in testing CXA81 Mk II, and why? How did these test tracks influence the final engineering decisions for the amplifier? 

"Elbow - Mirrorball: A favourite in the team for understanding detail and clarity. The punch of the drums, clarity of the vocals, timing, and presence. At 1:39, when the soundstage lifts, how dramatic and engaging it is.

 

Moloko – I Want You: Another favourite in the team for engagement and excitement. Does the beat get your toe tapping? How are the rhythm, timing and dynamics?

 

Gomez – Make No Sound: This is useful for picking out details in the raspy voice,  guitar strings, and drum clarity. At 1:43, when the sounds ramps up, can the amp handle this and how well? "
 

The Listening Experience: Why the CXA81 Mk II Stands Out

 

What specific tracks or types of music were pivotal in testing CXA81 Mk II, and why? How did these test tracks influence the final engineering decisions for the amplifier? 

"CXA81 was an award-winning amplifier for many years. What was the formula for creating such a lasting, successful product? How would you describe the nuanced improvements in the listening experience?

 

The CXA81 Mk II has an improved DAC, but the main story is the improvements made through tuning. With ten major component changes adding a significant cost increase, some layout enhancements, and months of listening and tuning work, we believe we have kept the CXA81 signature sound and added extra detail, clarity and a much-improved soundstage with real presence.  

 

How do we enhance the CXA81? We spent months understanding the design and hundreds of hours listening, improving, and refining. Well done, team!

 

The formula behind CXA81's longevity is the same one that gives us consistency across all of our products. We focus on the music, always compare to our own internal reference products, and improve with each generation—whether that requires a radical redesign or adding an extra level of refinement to solid foundations, as with the CXA81 Mk II. "
 

Volume Knob on CXA81 Mk II

The Verdict: Why Upgrade to CXA81 MKII? 

 

For someone considering an upgrade, what makes the CXA81 MKII a must-have in their audio setup? How does this product enhance the CX Series as a whole?

"When tuning CXA81 Mk II, we also had to factor in the development of CXN100. CXN100 has improved sound performance by adding extra detail and clarity and has an enhanced soundstage that matches CXA81 Mk II. The CXA81 Mk II is now the perfect partner for CXN100, as they are tuned with each other in mind. They perfectly complement each other in portraying the same audio presentation: extra detail, clarity and a much-improved soundstage with real presence. "
 

Final Thoughts 

 

In summary, what do you hope listeners will take away from their experience with CXA81 Mk II? 

"To fully appreciate the CXA81 Mk II, you simply need to relax, take a seat, and listen. We really hope you enjoy what our team have come up with. We believe it is a step up from the multi-award-winning CXA81, which was no mean feat!"

 

What does the release of the CXA81 MKII signify for the brand's direction and philosophy?

 

"The history of Cambridge Audio sound has always been fun, engaging, exciting and dynamic. Introducing our Edge range a few years ago pushed our performance boundaries with very high levels of detail, clarity and presence. CXA81 Mk II keeps the fun, engagement and excitement matching our history but adds much of that detail, clarity and presence in Edge. "

Nick Brown

Nick Brown

Head of Engineering 

Nick has been with Cambridge Audio for over 20 years, leading the engineering team in developing our award-winning hi-fi and audio products. 

His expertise bridges the gap between technical precision and the emotional experience of music, ensuring every product delivers sound with purpose. An old-school raver at heart, he's now a keen vinyl collector of 90s dance music. 

We've seen his collection - it's as formidable as his contributions to hi-fi!