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Power amplifier tests with respect to FTC: 16 CFR Part 432 (July 5, 2024) requirements on output power claims

So, finally, the test of Hypex UCD180HG stone age class D amplifier module. It passed the test, however, with derated power.


And, this is the spreadsheet of the results I have collected so far.

spreadsheet.png

 
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1. not gonna happen because of economical reasons.
2. marketing department not gonna let it to do. You can force it by politicians but that's an another rats nest.

I think the best solution would be to put the FTC rating into the datasheet and tech savvy people will have the chance to see it. Hypex includes the continues power rating which is a good sign imho.

Honestly normal people needs years or even decades to adjust and accept they need only 5-50W of amplification in their average room.
As I understand the ruling, manufacturers don’t need to disclose FTC-compliant ratings if they avoid referencing power output or related performance specifications. However, any advertised power claims must comply with FTC standards. Alternative ratings are allowed but must clearly state they were not tested under FTC standards and cannot take precedence over FTC-compliant ratings.

The claim that only 5–50 W of power is sufficient doesn't hold true for many individuals. Whether or not they align with your idea of "normal" is a topic best reserved for another thread, I think... :)
 
The claim that only 5–50 W of power is sufficient doesn't hold true for many individuals
Yes. It is again a caveat of individual opinion. And that is what we try to avoid, because as many people, as many opinions.
 
That's why I keep two spares "in stock" -- at less than $50 each, why not? :cool:
To your previous comment on A07, when I tested the A07 with 50V power supply, it gave 170W/4R with one channel loaded, though the manufacturer claimed 300W+300W those days. And it shut down after a while at this power level 170W. Then, after the interventions, they derated the power to 180W with 48V/10A power supply. At least some minor success of our efforts. And I do not care how loud you play in your garage, it is not any kind of a serious test.
 
To your previous comment on A07, when I tested the A07 with 50V power supply, it gave 170W/4R with one channel loaded, though the manufacturer claimed 300W+300W those days. And it shut down after a while at this power level 170W. Then, after the interventions, they derated the power to 180W with 48V/10A power supply. At least some minor success of our efforts. And I do not care how loud you play in your garage, it is not any kind of a serious test.
I was realistic about these things' actual capabilities from the getgo. Knowing my use case and being able to read the TI data sheet, I knew that I couldn't expect -- and wouldn't need -- anything near real world three-digit WPC and that A07s would be entirely adequate to their role in my particular system. Even their load impedance dependency is a non-issue here, since I feed them through a DSP unit anyway -- principally to EQ the speakers -- and could easily compensate for that. Moreover, I never take obviously exaggerated manufacturer-published specs for this sort of dirt-cheap gear seriously and don't consider my trouble-free experience "any kind of a serious test" -- I'm just testifying about an actual, relatively undemanding, and IMO fairly typical music listening application.
 
In the context of the fuktonnes of obsolescent and/or broken TVs, laptops, and phones being discarded on a daily basis worldwide, my conscience is clear with respect to the rather remote possibility of a failed A07 or two having some sort of dire environmental impact over the next decade or so. IOW, IMO you can stand down from red alert on that particular account -- but, of course, YMMV. :facepalm:
 
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Running at full rated power for five minutes is not horribly stringent; in what other world is "continuous" reduced to just five minutes?
In case of the Hypex the datasheet is pretty clear. Full rated power for continuous use is 50 Watts and can go higher with better cooling. Full rated power for short term (couple of minutes) is 200W or whatever.
 
In case of the Hypex the datasheet is pretty clear. Full rated power for continuous use is 50 Watts and can go higher with better cooling. Full rated power for short term (couple of minutes) is 200W or whatever.
Again, this thread is collecting data from a number of amplifiers measured by @pma so I was not hung up on one amp. Hypex does not specify the load for the 50 W rating IIRC but it wasn't particularly important to me. I am more concerned by the number of products that fail to meet the standard, some using Hypex modules. Finished products should follow the FTC rule, stating continuous power, and include dynamic specs.

Fundamentally I think a big part of the problem is consumer education. The reasons for the rule, and subsequent lower power ratings, should be made clear as should be the peak power ratings and why they matter. Having a 50 W amp capable of 250+ W peaks is a perfectly acceptable amplifier for most source material IME/IMO -- I'd buy it. I just don't like specsmanship and grandiose claims of continuous power that are not realistic and violate the FTC rule. The easy out for marketing is to headline the IHF dynamic power in the brochures and tout the high headroom available for music. Redesigning to handle the thermal load probably won't happen due to cost concerns, and is arguably not needful (to have say 250 W continuous power) by most users. There are exceptions, natch, so with a complete set of specs those who need higher continuous average power can choose an amp based on standard FTC testing and not guessing using inadequate data or from disingenuous advertising.
 
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So, what is their "rated power", then?? And do the OEM manufacturers-assemblers make the serious test and specify the rated power, or just point to the module datasheet?
My take on this spreadsheet is that it is to help an amp designer choose(or design) a heat sink. The "rated power" you input to the spreadsheet is your design goal for the product. If you want to use the module to build a 200W amp then you need this heat sink, but if you want to use the module to build a 50W amp then you use this smaller heat sink.
 
I used to have an amp that was properly rated at 30 watts class A according to the FTC rule. That is what the manufacturer called it. I used it on some very power hungry speakers. Why? Because it also could do peaks of more than 500 watts on 4 ohm loads just not long enough to meet the FTC rating or only in class A operation.
 
In case of the Hypex the datasheet is pretty clear. Full rated power for continuous use is 50 Watts and can go higher with better cooling. Full rated power for short term (couple of minutes) is 200W or whatever.
No it is not and I have quoted it above. For “maximum power”, neither signal duration, nor requirements on heatsink thermal resistance are defined. Everything is transferred as a responsibility to the OEM assembler. Definition of continuous 50W power is messed up with remarks about additional cooling. Please read the notes below their parameter charts.
 
I used to have an amp that was properly rated at 30 watts class A according to the FTC rule. That is what the manufacturer called it. I used it on some very power hungry speakers. Why? Because it also could do peaks of more than 500 watts on 4 ohm loads just not long enough to meet the FTC rating or only in class A operation.
Pass Labs, am I right?
 
Pass Labs, am I right?
No one of the early Classe DR 3 amps. In fact it was the VHC verision. Very High Current. A favorite among Apogee ribbon owners.

Nelson Pass did have some amps with what he called sliding class A.
 
So, what is their "rated power", then?? And do the OEM manufacturers-assemblers make the serious test and specify the rated power, or just point to the module datasheet?

My take on this spreadsheet is that it is to help an amp designer choose(or design) a heat sink. The "rated power" you input to the spreadsheet is your design goal for the product. If you want to use the module to build a 200W amp then you need this heat sink, but if you want to use the module to build a 50W amp then you use this smaller heat sink.

On thinking more, perhaps I missed the point of your question. Perhaps you are wondering what their definition of "rated power" is? In other words, is it rated power per the FTC rule, or perhaps to some other rule (e.g. rated power for 5 seconds instead of FTC's 5 minutes). That's a good question.
 
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