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

Matias

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Matias

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Thanks and congrats, Fred.

Whenever you have some time, could you also share the same graphs, SINAD % at 5W 1kHz and power at 1% THD+N 4 ohms 1kHz for all other models so that I add to the list please?
 

Haskil

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Bravo ! Fred !
 

Tom C

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Handling 6 color combinations has a cost that the margins on the 4215 can absorb without too many consequences. This is not the case for the other amplifiers. If it happens that most of our sales on the 4215 are done with the black cover, then the Ncore versions will switch to black.

On the boXem features, they are also present on the Ncore. I have shown that they have no impact on measurements here: https://www.audiosciencereview.com/...sed-power-amplifiers.16674/page-4#post-574416
On the buffer, it is a valid concern. To be completely transparent, when I designed it, my measurement system was not brilliant and the only thing I know is that it is equal or better that my measurement system in loopback. Now that I will have a better measurement system, I have no amplifier to be measured since power supplies are out of stock since months.

Let me put things in another perspective
On the help side
- I will soon be able to measure myself my amplifiers with an accuracy close to the AP555
- Several metrics that I consider as critical are not measured here
On the marketing side
- I am fighting to be able to build the amplifiers for actual customers who actually buy them. As written above, I don't even have one for my own reference.
- There have been at 4 Purifi amplifiers measured here. Two were very good, the Purifi demonstrator and one from Nord. Two from VTV that showed several issues. The result is that nobody recommends Nord and a lot of people recommend VTV. 'cos cheaper ya know. ;)
So why would I loose a sale, spend time and money on the shipping, spend time replying to the gang of armchair engineers and at the end the only result is that this helps sales from one of my competitors.
Some day a boXem product will be measured here. Two conditions:
- Amir agrees to do it
- It is unique on the market
While I can't answer to the first condition, the second one will soon be met.
I am curious which metrics you consider critical that are not measured on ASR.
 
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boXem

boXem

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I am curious which metrics you consider critical that are not measured on ASR.
Input impedance. Output DC. Both can cause system distortion.
For the 4215/E2, I chose to slightly increase the amplifier noise in order to keep the input impedance high and the output DC low.
For the 4222/E1 I found a solution allowing to get very low noise, high input impedance and low output DC.

BTW, this is a post from one year ago, in between I implemented a better measurement system and realized that the 4215/E2 residual noise was much better than what I thought at the time :rolleyes:.
 

Tom C

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Input impedance. Output DC. Both can cause system distortion.
For the 4215/E2, I chose to slightly increase the amplifier noise in order to keep the input impedance high and the output DC low.
For the 4222/E1 I found a solution allowing to get very low noise, high input impedance and low output DC.

BTW, this is a post from one year ago, in between I implemented a better measurement system and realized that the 4215/E2 residual noise was much better than what I thought at the time :rolleyes:.
Thank you. I see what you mean. It is critical to have these correct.
 

Ra1zel

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Impressive implementation
 

dan_uk

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Here is the latest little guy, based on Purifi 1ET7040SA. Little but able to output 700W in 2 Ohm
https://boxem-audio.eu/en/mono-amplifiers/28-arthur-4222e1.html

Some work was done on the input buffer in order to compensate the 1ET7040SA higher residual noise when compared to the 1ET400A. At the end, the 4222/E1 residual noise is lower than the one from the 4215/E2.
An active common mode rejection system is implemented in order to limit the risk of ground loop when RCA is used.
boXem amplifiers usual functions are available (audiosense, gain setting ...), with an RCA input and a 12V trigger (in and out) as new features.

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Loving these boxes, am very tempted to get a couple of mono blocs.... Does the audio sense work well? I've currently got a "Matrix Audio X-SABRE Pro MQA" DAC into a Meridian pre-amp for the sub output... Could I plug the Sabre directly into these mono blocs, I'm guessing I would loss the sub output tho....
 

vicenzo_del_paris

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Does the audio sense work well?

Like a charm ;)
It works perfectly.
I got my Arthur 3409 a year ago and the Audio sense has been bullet proof since.
Fed first by minidsp ddrc24 and then replaced by a minidps Flex.
 
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boXem

boXem

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... I've currently got a "Matrix Audio X-SABRE Pro MQA" DAC into a Meridian pre-amp for the sub output... Could I plug the Sabre directly into these mono blocs, I'm guessing I would loss the sub output tho....
If your preamp does high-pass filtering to the amp and speakers, I would keep it, this is a feature that is greatly limiting the speakers distortion notably IMD. Otherwise, you can plug the power amps to the XLR outs from the Matrix, the sub(s) to the RCA outs.
 

Haskil

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With acoustic speakers from Aykoz
 
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Haskil

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BoXem au Luxembourg Cinemotion Audioshow. Belle présentation.

oui excellent orateur en fait
Have you photos ?
 

Theodore8

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BoXem at Luxembourg Cinemotion Audioshow. Nice presentation.

yes excellent speaker actually
@BoXem: give us a heads up next time you make a presentation. Would love to attend!
 
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