I guess it would be interesting to hear from the handful of manufacturers that are active on this forum, explaining how their NC252/NCx252 amps address the cooling needs and avoid being one of the 'questionable builds'. Whether justified or not, anyone researching this product will surely have doubts on the long term reliability based on the reports, so it may be worthwhile companies highlighting on their websites how their build deals with the potential issues.
I do find it interesting that
@Apollon Audio - that has enjoyed some of the best reviews on this site and offers what appears to be a premium product, voluntarily admitted high failure rates in their build.
It is interesting that Hypex themselves have not addressed these issues, shared data or even officially declared the apparent improvement to the PCB flexing in the new model - which would be an indication that there was an issue with the previous version.
You are reading more into my comment than what was actually stated.
My remark was not about Apollon Audio builds being “questionable” in any way. It was a general observation about revision-related failure rates, something that is well known in electronics manufacturing. Early revisions of many modules, especially complex, all-in-one designs, tend to show higher failure rates compared to later, more mature revisions.
Specifically, I was referring to the Hypex MP series, which in our experience has shown a higher failure rate compared to Hypex’s higher-end offerings. This has nothing to do with the mechanical or thermal quality of our builds. Our assemblies are widely regarded as robust, conservative, and premium in terms of layout, grounding, cooling strategy, and component selection.
We have observed MP-series module failures:
- In our own products
- In professional, forced-air-cooled custom builds
- In commercial products such as Bowers & Wilkins subwoofers
- In Dynaudio subwoofers
- In Hypex Fusion plate amplifiers (which are also force-cooled)
In other words, these failures were module-related, not build-related.
When you place the SMPS and the Class-D output stage on the same PCB, thermally coupling multiple high-stress components, the outcome is predictable: elevated internal temperatures and reduced long-term reliability. This is not unique to Hypex MP modules. Similar issues were well documented with early revisions of ICEpower 1200AS2 modules as well.
All-in-one modules offer clear advantages in compactness and ease of integration, but they inherently involve thermal compromises. Increased thermal density almost always correlates with shorter lifespan, this is basic reliability physics.
As for PCB flexing or revisions, manufacturers rarely publish detailed internal revision data unless absolutely necessary. The absence of a public statement does not imply the absence of an issue, nor does it imply that third-party builds are at fault.
To be absolutely clear:
- Our comment was not an admission of build faults
- It was a transparent, experience-based observation about specific module families
- Apollon Audio builds have consistently demonstrated excellent reliability across a wide range of platforms and power levels
Transparency about module behavior, good or bad, is not a weakness. It is part of responsible engineering.
