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

[pma]

FTC "test" = reliability. Asserted with deeply felt emotion, but zero supporting evidence.

FTC "test" = useful data for consumers. Only for consumers interested in using the amp to run room heaters. It does NOT go to what consumers actually need for understanding how a product can suit their needs.

An assessment of the expert in the field of Polymer Chemistry. Interesting how many “experts” here have nothing in common with electrical engineering and education in electroacoustics.

 

[Multicore]

That it is a 10-15 W continuous amplifier, not the 55 or 77 W continuous amplifier that even an informed consumer, seeking out third party testing, might expect.

No, it would not. It world only reconfirm that it is not a 300 W amp.

 

[somebodyelse]

Amplifier Rule attached for those who want to read it themselves instead of being told what's in it from dubious sources.

That's not the whole Rule, just the changes from the last one, and the reasoning behind the changes. The full rule is at:
https://www.ecfr.gov/current/title-16/chapter-I/subchapter-D/part-432

 

[Mnyb]

Nope. FTC ruling is what is going to create false claims. That an amplifier that can perfectly produce 150 watts, is now forced to be advertised at 20 watts. This is wrong and goes against the very motivation listed by FTC in its request for comments:

How do we define this "perfectly produce 150 watt" ? there is no common ground here ? We are again back to assuming what music is which is strictly not possible .

I'm with you here i think for most music and most people this will be the case it will perfectly produce those 150 watts , but it can't be proven unconditionally thus not actually claimed as a spec .
You can probably produce a counterexample by wrong applying EQ and play Metallica's death magnetic for an hour if one counter example can be found this can not be a spec ?

We know that sines loads the amp much more than music , but by how much we cant really say for sure ? There need to be a standardized test signal that emulates "music" to be used for continues test by everyone . We can use this as proxy , but we can only claim that using this signal the amp gives that performance ?

Given my layman status . I'm sure there some standard burst or dynamic test signal ( the exact nature unknown to me ) we can use to judge the dynamic performance .

So a 20w continues and 150w dynamic power spec sounds good to me ? I would buy this .

 

[Old_School_Brad]

No, it would not. It world only reconfirm that it is not a 300 W amp.

What should the continuous power rating be, then? Test results suggest it's neither 300, 50, nor 20. Or do you completely disregard Pavel's test results in post #617?

 

[Esprit]

What legal value do FTC regulations have outside the USA?
I would say zero...

 

[pma]

Given my layman status . I'm sure there some standard burst or dynamic test signal ( the exact nature unknown to me ) we can use to judge the dynamic performance

Of course. IEC 60268-3

15.7.2 short-term maximum output voltage and power
15.7.3 long-term maximum output voltage and power
15.7.4 temperature-limited output power

 

[SIY]

An assessment of the expert in the field of Polymer Chemistry.

IOW, you have no substantive response, just ad hom.

 

[Old_School_Brad]

What legal value do FTC regulations have outside the USA?
I would say zero...

As mentioned already, the enforcement authority enables the FTC to issue warnings, impose fines, and potentially ban the import of foreign goods if manufacturers do not adhere to FTC regulations. This is dependent on the manufacturer actively targeting U.S. customers, either directly through advertising or indirectly by running a webshop that sells directly to U.S. customers.

 

[Multicore]

What should the continuous power rating be, then? Test results suggest it's neither 300, 50, nor 20. Or do you completely disregard Pavel's test results in post #617?

No. But it's beside the point.

 

[Sokel]

What should the continuous power rating be, then? Test results suggest it's neither 300, 50, nor 20. Or do you completely disregard Pavel's test results in post #617?

Do it the Rolls way: good enough
(God,I used analogy ² )

 

[pma]

That’s a good one, @Sokel . AIYIMA and Rolls-Royce. . I would rather say Trabant or Zaporozhets.

 

[Sokel]

That’s a good one, @Sokel . AIYIMA and Rolls-Royce. . I would rather say Trabant or Zaporozhets.

What's life without aiming high and dreaming?
After 38 pages I think we can safely conclude that there's not middle ground.

And people will still read that:

...and state "yeah (sic) ,I push half a kW to my 2-coilers" .
Sometimes it's sad.

 

[Esprit]

This is dependent on the manufacturer actively targeting U.S. customers, either directly through advertising or indirectly by running a webshop that sells directly to U.S. customers.

So: zero value outside the USA.
In Europe there are obligations regarding the consumption of products mainly in standby.
If a manufacturer sells me a product that is declared to be 100 watts for example but the power is lower, I have the right to a refund of my money because the product differs from what was declared (there could also be criminal problems such as "commercial fraud" and "advertising misleading").
I understand that for the topic in question the problem is and remains "how do we establish what the power of an amplifier is in a unique and recognized way in Europe, in the USA, in China?"
That's the point, and it's not the FTC rules that unequivocally establish it.

 

[pma]

Temperature limited output power according to IEC 60268-3

15.7.4 Temperature-limited output power
15.7.4.1 Characteristic to be specified
The output power which the amplifier is capable of supplying continuously, at a specified
ambient temperature, without exceeding the maximum permissible temperature in any
component.
When the amplifier is specified for different methods of mounting, for example, in enclosures
or in racks, the corresponding rated temperature-limited output powers shall be stated by the
manufacturer.
The rated temperature-limited output power may be less than the rated distortion-limited
output power, because in Class AB, B, or D amplifiers, the active devices operating in these
modes reach their maximum temperatures at output powers considerably less than the rated
output power, and the temperature maxima of several devices may be reached at different
output powers. Furthermore, where the d.c. supply to a stage is not stabilized, it is possible
for temperature maxima of different values to occur at two values of output power.
Amplifiers for which this is the case are satisfactory for amplifying normal speech and music
signals because of the amplitude/time characteristics of these signals (see 15.12.3.1, Note 1).

15.7.4.2 Method of measurement
Provisional tests at different output powers shall be made to determine the components which
are likely to reach their limiting temperature. Appropriate thermometers are mounted on the
components selected according to these provisional tests.
a) The amplifier, mounted in a specified way, is then brought under standard measuring
conditions except that the power supply voltage is adjusted to the upper limit of tolerance
of the rated power supply voltage for which the amplifier is set (see 15.2). The ambient
temperature shall be measured.
b) The source e.m.f. is adjusted in steps to increase the output voltage U2, waiting after each
step until the thermometer readings have become practically constant. This procedure is
maintained until at a certain output voltage U2' one of the components reaches its limit
temperature.
c) The temperature limited output power is U2'2/R2, where R2 is the rated load impedance.
The amplifier shall have worked continuously for at least 4 h under the conditions specified
before final temperature readings are made.
The manufacturer may optionally state the rated value in the specification.

 

[Sokel]

So: zero value outside the USA.
In Europe there are obligations regarding the consumption of products mainly in standby.
If a manufacturer sells me a product that is declared to be 100 watts for example but the power is lower, I have the right to a refund of my money because the product differs from what was declared (there could also be criminal problems such as "commercial fraud" and "advertising misleading").
I understand that for the topic in question the problem is and remains "how do we establish what the power of an amplifier is in a unique and recognized way in Europe, in the USA, in China?"
That's the point, and it's not the FTC rules that unequivocally establish it.

There's been at least a court case in Europe where the manufacturer lost,I think in Denmark (can't find the diyaudio thread) .
And the standard used to this case is the European one posted sometimes at this thread.

 

[Old_School_Brad]

So: zero value outside the USA.
In Europe there are obligations regarding the consumption of products mainly in standby.
If a manufacturer sells me a product that is declared to be 100 watts for example but the power is lower, I have the right to a refund of my money because the product differs from what was declared (there could also be criminal problems such as "commercial fraud" and "advertising misleading").
I understand that for the topic in question the problem is and remains "how do we establish what the power of an amplifier is in a unique and recognized way in Europe, in the USA, in China?"
That's the point, and it's not the FTC rules that unequivocally establish it.

It's important to understand how trade operates. They cannot simply drag anyone to court, if that's your assumption. Instead, they can encourage compliance with regulations through warnings and fines, and if a company still does not comply, they can enforce an import ban. Given that the U.S. is likely the largest market, this carries significant weight.
You’re correct that it’s not the main point, but it keeps being brought up repeatedly as a way to downplay the role of the FTC. It wouldn't be right to reach conclusions based on incorrect assumptions.
The consumer rights and market surveillance in the EU are quite robust. Incidents involving imported products that are deemed non-compliant and potentially dangerous to consumers occur regularly. While this may not directly relate to the current discussion, it serves as an example of trade and regulatory enforcement.

 

[Esprit]

There's been at least a court case in Europe where the manufacturer lost,I think in Denmark (can't find the diyaudio thread) .

As a consumer I know how to defend myself (I won a court against Amazon)
The point after dozens of pages of threads remains: how do we establish that an amplifier actually has that power?
How do we make it apply everywhere?
It seems to me that the rules are far from clear.
P.S. No, I haven't found the European legislation.

 

[Esprit]

Given that the U.S. is likely the largest market, this carries significant weight.

The main market for Chinese companies is China.
Polling on this forum suggests that there are, would be, more "foreign" users than Americans…

 

[Sokel]

P.S. No, I haven't found the European legislation.

It's the one posted just above,IEC 60268-3 .