Say "Hello!" to boXem Arthur series, Hypex and Purifi based power amplifiers

[boXem]

@boXem Hello Fred, on your website I noticed some errors in the Description and Product details of the Arthur 4216/E1.
In the Description: "In the Arthur 4216/E1, the amplification stage can deliver up to 375 W in 8 Ω and 1050 W in 2 Ω." doesn't seem right. In the Product details the Reference and Power stage(s) don't seem right.
Could you please check?
Edit: typos

A couple additional notes where it looks like there might have been some copy/paste errors:

In the 4216/E2 product description under "Purifi Eigentakt technology" it identifies the wrong Purifi module:

For the Arthur 4216/E2 we have chosen to implement the Purifi Eigentakt technology with the 1ET9040BA amplification stage.

Then as Nordling noted, it also lists higher power output (probably corresponding to the specs for the 1ET9040BA.

Finally, in the Product Details, the "Power Stage(s)" is incorrectly identified as the "Purifi 1ET9040BA".

Corrected, thanks guys!

 

[pogo]

There should be two more cables for the outputs that are not yet connected.
Why is the full potential of the new module not being used, as described in the data sheet?

 

[Theodore8]

Congrats @boXem on continuing to reach for the stars!

My Arthur 4215/E2 with matte grey case & anodized grey front plate with the historical logo has just become a rare collectible!

 

[boXem]

There should be two more cables for the outputs that are not yet connected.
Why is the full potential of the new module not being used, as described in the data sheet?
View attachment 389796

The two additional wires are here to enable a biwiring option. As you can see, this option is not available on our amplifier, partially due to the lack of space, partially due to my personal opinion on biwiring.
If, like I suspect, you are wondering why a few Watt are missing in 2R, it is due to the power supply chosen. I won't discuss the choice of PS any further, it is anyhow taboo on this site.

 

[pogo]

T+A A200 and Marantz Model 10 also do not use the full specified output power of purifi modules. This is purely an implementation decision and it is OK.

 

[boXem]

That's 1.25 dB less in sound power.

 

[whislai]

Corrected, thanks guys!

Congratulations for a new product which push the limit into such a small candybox!!! I'm surprised today as I saw the new Arthur 4216/E2, but it seem the board specification still not corrected, is this the correct one "Purifi 1ET6525SA power stage"? And the power delivered in different load:
In the Arthur 4216/E2, the amplification stage can deliver up to 210 W in 8 Ω and 510 W in 2 Ω.?

 

[boXem]

These parameters are correct, the Purifi 1ET6525SA replaces the famous 1ET400A and gains some Watt in heavy loads due to what appears to be an even better efficiency.

 

[whislai]

These parameters are correct, the Purifi 1ET6525SA replaces the famous 1ET400A and gains some Watt in heavy loads due to what appears to be an even better efficiency.

argh I think so, because I look wrongly, it was the mono amp I'm looking

 

[boXem]

Purifi sent us improperly calibrated modules. We had to ship back our entire stock and are waiting the parts back. At the moment we are stuck, not only on the measurement side.
Before the subject comes, amplifiers sent to customers are not impacted by this calibration issue.

 

[pogo]

Bridge-Mode calibration?

 

[boXem]

Common mode trim.

 

[boXem]

Development tests are done on the buffer only and by measuring noise and distorsion independently (quicker and more accurate). QC is quick and dirty stuff.
At the end, nothing publishable.
As soon as things go back to normal on the 1ET940BA front, I will have publishable stuff.

 

[blackiridium]

Purifi sent us improperly calibrated modules. We had to ship back our entire stock and are waiting the parts back. At the moment we are stuck, not only on the measurement side.
Before the subject comes, amplifiers sent to customers are not impacted by this calibration issue.

So 1ET6525SA are shipping?

 

[boXem]

So 1ET6525SA are shipping?

Subject here is 1ET9040BA, sorry for the confusion. 1ET6525SA still planned for mid October.

 

[LETRA]

Hello @boXem. I have been on hold for almost two months for the Arthur 4516/2 and I have received an email that the order is already being processed, I guess it will be shipped very soon. I went to the website and I thought I saw in the description of the Arthur 4516/2 a new detail that was not there before: "Input and gain stage with exclusive boXem stage III composite topology". Could you explain what it is and what other changes you have made in this new 4516 with respect to the 4515 apart from Purifi module?

Best regards.

 

[boXem]

Hello @LETRA . Your order has actually been shipped. I hope that you did receive our emails informing about the additional delays and didn't worry too much whether you would receive your amp or not.
The product description has not changed (apart some typo) since we started selling the Arthur 4216/E2. The composite topology consist in splitting the tasks between opamps, one supplying the current, the other controlling the noise and distortion.
The input stage was completely redesigned. 4 layers PCB and ultra low noise regulators are the main changes - in addition to the composite opamp - compared to the previous generation.

 

[LETRA]

Hello @LETRA . Your order has actually been shipped. I hope that you did receive our emails informing about the additional delays and didn't worry too much whether you would receive your amp or not.
The product description has not changed (apart some typo) since we started selling the Arthur 4216/E2. The composite topology consist in splitting the tasks between opamps, one supplying the current, the other controlling the noise and distortion.
The input stage was completely redesigned. 4 layers PCB and ultra low noise regulators are the main changes - in addition to the composite opamp - compared to the previous generation.

Hi @boXem. Yes, I have received the e-mails and shipping notification that the package will be delivered to me on Monday. The wait all this time yes it has been harder. Hopefully now customers will be able to get it very quickly from now on. I have been an early adopter and have had to be very patient.

Thanks for the explanations on the changes from Arthur 4215, I will follow with interest any discussion you have here on how this affects in terms of sound quality improvement.

Best regards.

 

[boXem]

Fred,
Can you hear or measure a difference between the composite topology in the 4216/E2 versus the 4215/E2 input stage?
Thank you!

Hear: well we are on ASR... I have the feeling that having the channels running out of phase (another difference with the previous generation) improved the bass. For the rest, if there is an audible difference, it is extremely subtle.
Measure: I never measured the old buffer with the new measurement system. The only data I have are with the Motu M2 as DAC/ADC, so the difference would not be realistic, the chain Su9n - A70Pro - Cosmos ADC being much lower noise and distortion by itself. But that's a good idea, in the to do list once all orders will be fulfilled.

 

[Oniiz86]

Hear: well we are on ASR... I have the feeling that having the channels running out of phase (another difference with the previous generation) improved the bass. For the rest, if there is an audible difference, it is extremely subtle.
Measure: I never measured the old buffer with the new measurement system. The only data I have are with the Motu M2 as DAC/ADC, so the difference would not be realistic, the chain Su9n - A70Pro - Cosmos ADC being much lower noise and distortion by itself. But that's a good idea, in the to do list once all orders will be fulfilled.

@boXem I was just curious why having the channels out of phase for the 2 Ch variant of the 4216 was necessary as I thought the Hypex SMPS1200A400 is a 2 Quadrant design thus will not suffer from power supply bus pumping effects, I thought it was only deemed necessary with the SMPS3kA400 as that is not a 2 Quadrant design?