With derailing this discussion that is over my head, is class B really an embodiment of that size or at all? examples?
That is a $4000 question!
With derailing this discussion that is over my head, is class B really an embodiment of that size or at all? examples?
Interestingly, dynamic headroom was the only spec Erin questioned...No,I don't mind at all!
It just isn't my taste,I prefer black stuff.
They also state dynamic headroom,3dB,so double the whole stuff when needed.Not bad at all!
Many discussions on this topic don’t really try to understand different viewpoints. People jump to conclusions and focus on proving their points or questioning others' knowledge instead of having a productive conversation. This is especially true for rhetorical questions of the kind, which everyone here probably already knows the answers to and thus don’t really help move the discussion forward.Doing what exactly? Playing sine waves? If so, go ahead and run that test and see how loud you can tolerate it and then run it for 5 minutes. Report back if amp goes into protection or dies.
If you mean playing music, then do the same and report on that.
Amplifiers are simply not shutting down for people after 5 minutes of playing music or they wouldn't be able to sell much or any.
It would be more enlightening if Hypex purify and TI et all could explain thier modelling for this .Reading this document with understanding should close this ineffective yet emotional discussion.
Yep,and it even falls short by their rating (450W so it should be 900W) .Interestingly, dynamic headroom was the only spec Erin questioned...
"...McIntosh’s “Dynamic Headroom” is rated at 3.0dB. If one were using my data then we see at 4-ohms the continuous power vs max peak (headroom/dynamic range) at 1% THD+N 546 watts and 823 watts, respectively (left channel). For a true 3dB of ‘headroom’ - which is doubling of power - the max peak power would have to be closer to 1092 (546w*2) or the max continuous would need to be 411.5 watts (823w/2)..."
He admits to being a Mcfanboy and ends up rationalizing why the amp missed the mark. For the price, would hope it is great. Would buy a Purifi amp and spend the remainder on some really nice speakers.
Potentially. It would require member attorneys wanting to file a lawsuit against them. Alternatively, I have thought of reaching out to CTA as they would have the resource for this. From a practical point of view though, we should wait to see if they lift a finger to enforce anything.
- Do you believe you, Amir, have the ability to influence changes to the FTC’s amplifier testing regulations? (This is an honest question, as your reach in this area is not clear to me.)
Before this discussion came up, I was already thinking about stressing amplifiers more. You have seen one example of such tests show up recently:
- If the FTC rule cannot be changed, would you:
A) Choose to disregard it altogether, or
B) Continue by testing amplifiers in line with FTC standards?
I prefer to not create a special test for class D.
- Would you instead consider advocating for a more practical power rating system that better reflects the real-world performance of amplifiers, particularly Class-D designs?
There is zero mention of it running at full power for 5 minutes. The TO-3 transistors are laying flat instead of properly being mounted on the side heatsinks. The thermal impedance as a result, is much higher, necessitating that fan in the back. The fan is poorly located with no fluid dynamics analysis for proper air circulation. To be sure, it does a lot more than nothing but not remotely proper.
Get a modern PA amp and it too, with a fan, will run reliably, producing gobs more power than it. And it would sell for a fraction of what that amp cost.
And oh, they break down as well, lest you once again be claiming that the older amps didn't break. Here is a quick google search: https://www.diyaudio.com/community/threads/perreaux-8000c-left-channel-not-working-need-help.325666/
"I have a Perreaux 8000c ..lately the left channel started to get crackly and staticky and also little pop sounds .I have to mention that I have 3 6000c as well that have very similar symptoms "
To claim that the older amps didn't break is absurd. The only thing more absurd is claiming that after decades, they are still reliable. All amplifiers break. I actually trust the class D ones far more because a) they run so much cooler and b) they are so easy to repair with a module swap.
I have no intention whatsoever to run a 5 minute max power test at full bandwidth.
I think I am going to grow old and die before you show us a single, full power, full bandwidth test of any amplifier for 5 minutes.....You are demonstrating just how little you know about Perreaux amplifiers, the company, the founder (Peter Perreaux) and just how reliable they were. They are merely an example I used. I have hundreds of other examples I could use.
FTC rule is not a standard. It is a regulation created by lay people at a government agency with no understanding of the underlying technology or even the test itself. A standard is created by technical people through many stages. Nothing remotely like that happened with FTC. As I mentioned, FCC (Federal Communication Commission) does that kind of work in the way it uses other major standards organizations for transmission and TV technologies. FTC (Federal Trade Commission) is a trade watchdog and should stay out of creating ad-hoc rules that are bad for both consumers and companies.So you'll obviously be putting a nice fat disclaimer on the power output test results saying "This amplifier was not tested under the FTC standard" lest someone looking to purchase, based on your technical reviews could potentially be misled as to the actual continuous available power of the product? Should be a fun time for all.
There is nothing to misrepresent. You keep championing something that you haven't practiced at all. Ditto for @pma and his random tests. Not a single company, reviewer, or organization has shown a single test result per FTC 2024. The ruling is not practicable much less useful.And you are now attempting to re-write and misrepresent what I have said.
I don't care if Moses came down and handed the amplifier to each one. Every amplifier fails. You have hard data saying otherwise, let's see it.You are demonstrating just how little you know about Perreaux amplifiers, the company, the founder (Peter Perreaux) and just how reliable they were.
We don't know this. Amplifiers fail for many reasons. Some just fail to turn on one day. Some component can just fail for random reason. Or have the amp get subjected to conditions not tested. Standard protection circuit shuts down the amp if it is getting too hot.On longevity, it's clear that thermal management is key.
One doesn't know the quality and rating of the capacitors used. It really goes beyond any kind of quick analysis.If elevated idle temperature, in Amp and power supply, is what slowly cooks components and reduces amplifier life - can that be measured too?
Fair enough, I was simplifying - went too far. I still think that thermal management is an important factor at idle and at higher power levels but I take your point.We don't know this. Amplifiers fail for many reasons. Some just fail to turn on one day. Some component can just fail for random reason. Or have the amp get subjected to conditions not tested. Standard protection circuit shuts down the amp if it is getting too hot.
Long term, yes, caps can dry out and such. But we can't do failure analysis so simply.
Agreed.One doesn't know the quality and rating of the capacitors used. It really goes beyond any kind of quick analysis.
Such testing is best left to manufactures. Sony for example would cook dozens of units in a room overnight and see if the failures follow any pattern or are above certain rate.
High power amps (NCx500,icepower 1200as,etc) are warm even at idle (but strangely cool down when play a little louder,not max though) while low power ones usually (I say usually,don't take fosi's monos for example) are cooler.Nicer ones like Purifi are cooler,but I don't know about their high power one,still haven't put my hands on it)Fair enough, I was simplifying - went too far. I still think that thermal management is an important factor at idle and at higher power levels but I take your point.