ASR only provides basic measurements for audio equipment. Other than that, the operation and sound quality of the actual equipment are items that should be judged by each member.Why does the review thread still include a strong recommendation yet no mention of obvious quality issues? Occam’s Razor says @amirm is taking kickbacks from Topping which completely destroys the credibility of the entire forum.
Why does the review thread still include a strong recommendation yet no mention of obvious quality issues?
The amp was accurately reviewed with respect to performance. I bought one based on the performance, with the understanding that I was buying a newly released product. Quality and Reliability are another thing and beyond the scope of any reasonable review and need time to develop data.Why does the review thread still include a strong recommendation yet no mention of obvious quality issues?
Accusing people of taking kickbacks is not cool. There is no evidence of that. Also, you misuse Occam's Razor to jump to this conclusion.Occam’s Razor says @amirm is taking kickbacks from Topping which completely destroys the credibility of the entire forum.
Occam’s Razor says @amirm is taking kickbacks from Topping which completely destroys the credibility of the entire forum.
The power amplifier tests should be much more severe than the set of measurements performed by @amirm . Amplifiers should be tested with continuous sine for longer period of time and at higher power, to disclose thermal design issues that affect the reliability and longevity. Complex load to be used to disclose possible stability issues. Square wave to be used for the same reason. As of the current status of tests, they are close to pointless. They support cheap designs that are oriented to low level 1kHz SINAD, which is not very useful for the user. I do not understand why an experienced engineer like @solderdude is protecting such way of testing. It seems to me that @restorer-john is of very few here who understands amplifier testing. @amirm is not the one.Why does the review thread still include a strong recommendation yet no mention of obvious quality issues? Occam’s Razor says @amirm is taking kickbacks from Topping which completely destroys the credibility of the entire forum.
The power amplifier tests should be much more severe than the set of measurements performed by @amirm . Amplifiers should be tested with continuous sine for longer period of time and at higher power, to disclose thermal design issues that affect the reliability and longevity. Complex load to be used to disclose possible stability issues. Square wave to be used for the same reason. As of the current status of tests, they are close to pointless. They support cheap designs that are oriented to low level 1kHz SINAD, which is not very useful for the user. I do not understand why an experienced engineer like @solderdude is protecting such way of testing. It seems to me that @restorer-john is of very few here who understands amplifier testing. @amirm is not the one.
The power amplifier tests should be much more severe than the set of measurements performed by @amirm . Amplifiers should be tested with continuous sine for longer period of time and at higher power, to disclose thermal design issues that affect the reliability and longevity. Complex load to be used to disclose possible stability issues. Square wave to be used for the same reason. As of the current status of tests, they are close to pointless. They support cheap designs that are oriented to low level 1kHz SINAD, which is not very useful for the user. I do not understand why an experienced engineer like @solderdude is protecting such way of testing. It seems to me that @restorer-john is of very few here who understands amplifier testing. @amirm is not the one.
Well stated. And to add, many of these tests are stress-to-fail under accelerated conditions on a population of units. This is to sort out early-life-fails from wear-out. The data is only useful on a population, and the units are destroyed by the end of the test. And many of the non-destructive tests do leave the unit degraded (Bias Temp Inversion degradation to semiconductors, parasitic leakage degradation passives, etc.) Companies that prize Quality and Reliability spend lots of time developing these tests based on the architecture and use condition of the product. Many of these tests need to be done on the subsystems during product development and can't even be done on the full product!The problems reported about DOA or devices giving all kinds of tests (reliability) will also not be found when more than just a handful of standard tests are done.
Sure you can get (lots) more data about performance and I can insist time and time again that more measurements are needed to fully characterize an amp but Amir does his measurements regardless.
Sure. In some of the more rigorous tests some amps will fall flat on their nose and show less performance than the basic measurements Amir does. And yes some amps might go in protection and maybe some will blow up even.
As long as no EMC/ESD tests are done (at more extreme limits) and extensive tests are done and you can not open up devices without losing warranty (when sent in by owners) it will be really hard to predict if FW upgrades are going to be made or about longevity and potentially destructive tests are done I sure as hell cannot predict how many devices might or will fail in some (catastrophic) way.
When you test your own amps and throw all kinds of tests at it is another matter and would be very easy to fix.
That's why I 'support' Amir's measurements. I rather have at least some basic measurements than no measurements and understand that not only doing measurements and setups takes time but also reporting it.
Even simple EMC/ESD tests of something like an amp with a few input and output ports can take up 2 whole days not counting reporting and destructive tests.
Do I wish for more measurements.... sure. Will I get it by demanding anything from Amir ? Nope.
Are you (or @restorer-john) volunteering to take on the testing and liability, because that would be a fantastic contribution given your expertise!The power amplifier tests should be much more severe than the set of measurements performed by @amirm . Amplifiers should be tested with continuous sine for longer period of time and at higher power, to disclose thermal design issues that affect the reliability and longevity. Complex load to be used to disclose possible stability issues. Square wave to be used for the same reason. As of the current status of tests, they are close to pointless. They support cheap designs that are oriented to low level 1kHz SINAD, which is not very useful for the user. I do not understand why an experienced engineer like @solderdude is protecting such way of testing. It seems to me that @restorer-john is of very few here who understands amplifier testing. @amirm is not the one.
Why does the review thread still include a strong recommendation yet no mention of obvious quality issues? Occam’s Razor says @amirm is taking kickbacks from Topping which completely destroys the credibility of the entire forum.
if there is a yield problem it should be reported to Topping (which BTW I think is well aware of the matter).
It's not at all clear that Topping is aware of the matter. If you know where Topping has acknowledged there is a problem, please point us to it. If you know where they describe what the problem is, please point us to it.
I also run my PA5 at full volume controlling the volume with the pre. I don’t feel my amp getting too hot. Warm, yes. On month 6 with no problems.I don't have hard evidence but I think my PA5 runs cooler when set to max volume and using my E50 in PreAmp mode to control volume vs DAC mode.