Buckeye Purifi Eigentakt 1ET9040BA monoblock power amplifier Stereophile Measurements

[restorer-john]

Sadly, based on @John Atkinson 's testing, it's just another amplifier that doesn't even come close to its advertised power output specifications.

As for the THD, where did that figure get plucked from? It's not even in the same ballpark at any frequency or power.

And, it seems @Buckeye Amps is not even specifying his amplifiers on his website according to FTC power output advertising regulations, even after being well aware of the need to do so, months and months ago. Why Dylan? I figured you wouldn't want to be that guy...

 

[JustJones]

Sadly, based on @John Atkinson 's testing, it's just another amplifier that doesn't even come close to its advertised power output specifications.

As for the THD, where did that figure get plucked from? It's not even in the same ballpark at any frequency or power.

View attachment 415344

And, it seems @Buckeye Amps is not even specifying his amplifiers on his website according to FTC power output advertising regulations, even after being well aware of the need to do so, months and months ago. Why Dylan? I figured you wouldn't want to be that guy...

Are there any manufacturers doing this yet ?
Anyway there's a petition to reopen before the FTC on this regulation which they haven't responded to yet. The comments closed on November 8th so probably still a month or so.

 

[PGansz]

The amps got a glowing review in the subjective tests - that alone should produce excellent results for Buckeye from Stereophile readers and other media.

JA gave it a great review as well. Clearly there's some issue to clean up and while not making close to rated power, this publication testing $20k amps that make half the power and recommending them now speaks volumes for new class D designs.

Great amplification at low prices is now a real thing to the high-end community. Progress.

 

[Holmz]

The amps got a glowing review in the subjective tests - that alone should produce excellent results for Buckeye from Stereophile readers and other media.

JA gave it a great review as well. Clearly there's some issue to clean up and while not making close to rated power, this publication testing $20k amps that make half the power and recommending them now speaks volumes for new class D designs.

Great amplification at low prices is now a real thing to the high-end community. Progress.

Alternatively… the drive to lower and lower driver impedance, and more and more wild impedance in the crossover, sort of created a requirement for amps with huge power.
There is a difference in a 6 or 8 ohm driver and the 2-3 ohm drivers, that is somewhat at fault here.

 

[amirm]

And, it seems @Buckeye Amps is not even specifying his amplifiers on his website according to FTC power output advertising regulations, even after being well aware of the need to do so, months and months ago. Why Dylan? I figured you wouldn't want to be that guy...

You don't have a business to run. Unless the entire industry overnight switches to this faulty FTC regulation, no one will, lest they want to look really bad for no good reason. The amplifiers were plenty loud for Kal, matching the performance of other amplifiers which likely could product higher 20 kHz power. Indeed, he could not dare finding the limit of their power. It would be stupid to rate them at 74 watts @20 kHz.

 

[restorer-john]

You don't have a business to run. Unless the entire industry overnight switches to this faulty FTC regulation, no one will, lest they want to look really bad for no good reason. The amplifiers were plenty loud for Kal, matching the performance of other amplifiers which likely could product higher 20 kHz power. Indeed, he could not dare finding the limit of their power. It would be stupid to rate them at 74 watts @20 kHz.

Nothing like scoring own goals, Amir. If you can't see how hypocritical your comments are, I really can't help you.

Oh, and read the review- all of it. It didn't come anywhere near rated power or distortion even at 1kHz into any load. It shutdown into all loads well before that. Stop making excuses, please.

 

[amirm]

Oh, and read the review- all of it. It didn't come anywhere near rated power or distortion even at 1kHz into any load. It shutdown into all loads well before that. Stop making excuses, please.

I read it. It is proof that FTC regulation is crazy bad. An amplifier that produced incredible subjective power, and some 450 watts at 1 KHz, would have to be rated at 74 watts per FTC! This is what happens when economists and lawyers try to set technical standards. Thankfully, you would go deaf with 75 watts at 20 kHz -- assuming you could hear that frequency. And would easily damage your tweeter for the 5 minute run time.

What's more, JA's test is insufficient to meet FTC regulations. It was not for 5 minutes. Nor was it from 20 to 20 kHz. No one knows how to run this test as written.

Finally, we don't know the FTC's rule for bandwidth of THD+N measurement and I couldn't find the same in JA's test. If you set it to 20 kHz, it wouldn't collect any ultrasonic noise or harmonics. And with it, potentially generate more power.

Net, net, this is the mess we have on our hand. Regulation that is vague, can't be implemented, and generates completely faulty data contrary to consumer's real application (music) and experience (loudness).

 

[amper42]

8 ohms - "amplifier went into protection at 290W" - (77% of Buckeye power claim of 375W)
4 ohms (fig.5), it did so at 450W - (60% of Buckeye power claim of 750W)
2 ohms (fig.6), it turned off at 660W - (55% of Buckeye power claim of 1200W)

This doesn't seem like a small miss to me. If these results were achieved in an ASR review wouldn't it likely be considered a major failure with a panther head rolling on the floor?

 

[amirm]

If these results were achieved in an ASR review wouldn't it likely be considered an major failure with a panther head rolling on the floor?

Not at all. My conclusion has nothing to do with what the vendor has claimed. I look at all the data, apply my subjective impression of features and build quality, and give a recommendation. A 15 pound amplifier producing 450 watts with incredibly low distortion is a great find and would provide amazing performance for users. No way do I want to tell people not to buy it because of what they say on their website. I am not a website police.

Yes, I make a few exceptions here and there but the above is the rule.

 

[amirm]

Also, please don't apply my conclusions to someone else's data. My testing has some overlap but a number of other tests and it is that totality that would form my judgement.

 

[kyuu]

It would be good to know why it didn't meet its targets, as I doubt Buckeye has any intention of posting figures that the gear can't meet. He also stated that the results don't match his own testing IIRC.

Regardless, I don't know how anyone could be anything but thrilled with the performance even at the test results.

 

[tmtomh]

And, it seems @Buckeye Amps is not even specifying his amplifiers on his website according to FTC power output advertising regulations, even after being well aware of the need to do so, months and months ago. Why Dylan? I figured you wouldn't want to be that guy...

@Old_School_Brad , now you can see precisely why the amp makers haven't been very active in pm's FTC 2024 test rules thread. This kind of gratuitous, personalized, ad hominem BS questioning their personal ethics would await them - you can see here that John was lying in wait for any amp maker dumb enough to walk into that, so he's gone outside the thread and hung it here as a tangent.

 

[Old_School_Brad]

That has since occurred to me and it would explain why John thinks there's no need to do preconditioning - although there are slots in the top, there's not much chimneying going on, unlike a vertically mounted heatsink with a large surface area.

Even a closed chassis has some heat transfer from the components inside. But via. near still air. Which is not good...

@Old_School_Brad , now you can see precisely why the amp makers haven't been very active in pm's FTC 2024 test rules thread. This kind of gratuitous, personalized, ad hominem BS questioning their personal ethics would await them - you can see here that John was lying in wait for any amp maker dumb enough to walk into that, so he's gone outside the thread and hung it here as a tangent.

It’s my experience that it is always better to confront issues head-on rather than ignore them.

Here, we have an amplifier that falls short of its advertised power and distortion specifications. As a manufacturer, addressing these discrepancies directly and investigating the root causes is crucial to prevent speculation no matter if reactions are emotionally driven or even unpleasant.

The performance figures are as follows:

• 8 ohms: The amplifier went into protection at 290W, achieving only 77% of the claimed 375W.
• 4 ohms (fig. 5): Protection triggered at 450W, which is 60% of the claimed 750W.
• 2 ohms (fig. 6): It shut down at 660W, just 55% of the advertised 1200W.
• Additionally, distortion levels are approximately 30 dB (?) worse than specified, which is currently under investigation.

 

[Buckeye Amps]

FWIW: we have our own data from months ago showing no issue with the amp going into protection during power sweeps and also meeting the power spec goals.

As I have said in our official thread, we will be doing more testing in the new year to further back up what we have already observed on our end.

I am in no way saying JA did anything wrong, is faulty, etc. It is something that at this moment can't be explained and is at odds with previous data. So being the trained scientist I am, will not begin to speculate or draw conclusions until more data is collected and added to the mix.

 

[tmtomh]

Even a closed chassis has some heat transfer from the components inside. But via. near still air. Which is not good...


It’s my experience that it is always better to confront issues head-on rather than ignore them.

Here, we have an amplifier that falls short of its advertised power and distortion specifications. As a manufacturer, addressing these discrepancies directly and investigating the root causes is crucial to prevent speculation no matter if reactions are emotionally driven or even unpleasant.

The performance figures are as follows:

• 8 ohms: The amplifier went into protection at 290W, achieving only 77% of the claimed 375W.
• 4 ohms (fig. 5): Protection triggered at 450W, which is 60% of the claimed 750W.
• 2 ohms (fig. 6): It shut down at 660W, just 55% of the advertised 1200W.
• Additionally, distortion levels are approximately 30 dB (?) worse than specified, which is currently under investigation.

Ironic that you'd extoll the virtues of confronting issues head on in the same breath that you deflect from the point I was making. You'll note that I quoted only the part of John's comment where he questioned Dylan's personal integrity for not adhering to the new FTC rule in advertising power ratings - which has nothing to do with the Stereophile measurements in question or with the the performance figures you have quoted.

I agree the amp does not meet the advertised power, as per what you and others have listed here.

But that's not what I my comment is about. My comment was about, well, it's very clear what it was about, and I've just reiterated it. I made the comment because I too find that it's always better to confront issues head on rather than ignore them. So why are you ignoring this issue?

 

[Old_School_Brad]

FWIW: we have our own data from months ago showing no issue with the amp going into protection during power sweeps and also meeting the power spec goals.

As I have said in our official thread, we will be doing more testing in the new year to further back up what we have already observed on our end.

I am in no way saying JA did anything wrong, is faulty, etc. It is something that at this moment can't be explained and is at odds with previous data. So being the trained scientist I am, will not begin to speculate or draw conclusions until more data is collected and added to the mix.

That’s the right approach.

Best of luck with your search.

 

[Old_School_Brad]

Ironic that you'd extoll the virtues of confronting issues head on in the same breath that you deflect from the point I was making. You'll note that I quoted only the part of John's comment where he questioned Dylan's personal integrity for not adhering to the new FTC rule in advertising power ratings - which has nothing to do with the Stereophile measurements in question or with the the performance figures you have quoted.

I agree the amp does not meet the advertised power, as per what you and others have listed here.

But that's not what I my comment is about. My comment was about, well, it's very clear what it was about, and I've just reiterated it. I made the comment because I too find that it's always better to confront issues head on rather than ignore them. So why are you ignoring this issue?

I would appreciate it if you could avoid using my posts as a way to address or criticize others. I’m not in disagreement with you, but this has happened before, and I’d like to steer clear of being involved in any ongoing conflicts. I prefer to stay neutral in any disputes between you, PMA, or John. Thank you for understanding.

 

[SMPSGuy]

I am absolutely sure it is not a difference between 1ET400A and1ET9040BA, but the difference would be in case material. If the Buckey case is made from iron steel, then the coils in the Purifi module become nonlinear (nonlinear core) and the best way to test this is high level 19+20kHz IMD (not the usual 5W). Even 20kHz THD would not indicate the issue.

Good Grief. I have not read the whole thread in order to understand why it has descended to this but every Purifi amplifier I have seen uses an RM pot core for the output inductor which is extremely good at enclosing the magnetic field. As to the case material disturbing that one perhaps the original poster can provide their reluctance model of the total system using an Aluminum and Mild Steel case so lesser mortals can gain some insight into how many micro-percent difference it makes then compare it to non-linearity in the gapped core material itself. I would do the hard work for you but it's not my hill to waste time on.

 

[Hayabusa]

I was reading the datasheet and all protection modes are self restoring and should not need a power cycle as JA was saying.
Another weird detail.

 

[tmtomh]

I would appreciate it if you could avoid using my posts as a way to address or criticize others. I’m not in disagreement with you, but this has happened before, and I’d like to steer clear of being involved in any ongoing conflicts. I prefer to stay neutral in any disputes between you, PMA, or John. Thank you for understanding.

My comment was directly and very specifically in reference to a question that you actively pursued through multiple comments in that other thread. You repeatedly professed not to understand why amp makers would not want to post in that thread, and John's tangential, ad hominem attack on Dylan here is precisely what I said would happen if an amp maker posted there. So my tagging you here was not meant to try to enlist your support, but rather only to call your attention to it. Now you have your answer to the question you posed in the other thread.

I do understand what you are saying in the above-quoted comment, and I can say that I have no intention of tagging you in that way in my future comments, so I think there won't be a problem in that regard.