• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

boXem Arthur 4222/E1 Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 8 2.3%
  • 2. Not terrible (postman panther)

    Votes: 11 3.1%
  • 3. Fine (happy panther)

    Votes: 60 16.9%
  • 4. Great (golfing panther)

    Votes: 275 77.7%

  • Total voters
    354

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
39,994
Likes
185,568
Location
Seattle Area
This is a review and detailed measurements of the boXem Audio Arthur 4222/E1 mono power amplifier. It was sent to me by the company and costs €1,490.00.
BoXem Arthur 4222E1 Monoblock Amplifier review.jpg

The design is quintessential European with gray body and colorful front panel which I like. The only power button is on the back:
BoXem Arthur 4222E1 Monoblock Amplifier back panel balanced review.jpg

Fortunately you have trigger input so you can set it to power up when the source turns on. Three gain settings are provided which is very nice. Unlike some amps in its class, it has both XLR balanced and RCA unbalanced inputs.

The amplifier is class D and is based on Purifi 1ET7040SA module.

EDIT: amp is 4222, not 4215.

boXem Arthur 4222/E1 Measurements
I started with the input gain set to low:
BoXem Arthur 4222E1 Monoblock Amplifier Measurement.png


This is superb performance and easily lands the unit in our top 5 amplifiers ever tested:
Best amplifier review audio.png

To get to full power with low gain, you need 9+ volts of input. So I set the amp to medium gain where 4 volts is enough to push it into clipping. Performance thankfully remains the same:
BoXem Arthur 4222E1 Monoblock Amplifier Medium Gain Measurement.png


Signal to noise ratio is exceptional:
BoXem Arthur 4222E1 Monoblock Amplifier SNR Measurement.png


Low distortion translates into very high distortion-free dynamic range:
BoXem Arthur 4222E1 Monoblock Amplifier Multitone Measurement.png


Frequency response is load independent and quite flat in audible band:
BoXem Arthur 4222E1 Monoblock Amplifier Frequency Response Measurement.png


There is healthy amount of power available into 4 ohm:
BoXem Arthur 4222E1 Monoblock Amplifier Power into 4 ohm Measurement.png

BoXem Arthur 4222E1 Monoblock Amplifier Max and Peak Power into 4 ohm Measurement.png


Company asked me to also test 2 ohm performance:
BoXem Arthur 4222E1 Monoblock Amplifier Power into 2 ohm Measurement.png


We get the same low noise and distortion into 8 ohm:
BoXem Arthur 4222E1 Monoblock Amplifier Power 8 ohm Measurement.png


There is some "ballooning" of the distortion curve at higher frequencies:
BoXem Arthur 4222E1 Monoblock Amplifier Frequency vs Power into 4 ohm Measurement.png


As noted, this is still very good for class d amplifier.

Conclusions
Building on solid foundation of Purifi amplifier module, the 4215/E1 delivers the goods with tons of power with very low noise and distortion. And it does so in a compact and attractive box with nice feature list. Not sure what else there is to ask for. Yes, the price is a bit high but you are getting European build and support so you need to value that as well.

It is my pleasure to recommend the boXem Arthur 4222/E1 amplifier.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited:

Axo1989

Major Contributor
Joined
Jan 9, 2022
Messages
1,052
Likes
904
Very nice implementation of the 7040 from Boxem. Good to see performance into 2Ω. Will the amp be kept or returned?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
39,994
Likes
185,568
Location
Seattle Area
Very nice implementation of the 7040 from Boxem. Will the amp be kept or returned?
Returned. He has asked me multiple times to send them back!!!
 

JSmith

Major Contributor
Joined
Feb 8, 2021
Messages
3,491
Likes
8,076
Location
Algol Perseus
Fortunately you have trigger input so you can set it to power up when the source turns on.
Plus it still has;
Plug your audio source (with volume control), your speakers, the mains cable, switch on the mains, and forget your amplifier. The automatic on/off function detects the presence of sound at the input and automatically powers on the amplifier. After 10 minutes without sound at the input, the amplifier sets itself in standby, allowing an ultra low power consumption when not in use.
If you are equipped with electronics featuring a trigger function, 12V trigger in and out connectors are also available.

Nice to see one of the Purifi boXem's tested here Amir, performance and build quality is excellent.
1664691778562.png

1664691813678.png


Nice job @boXem | audio.


JSmith
 

ririt

Senior Member
Joined
May 5, 2020
Messages
360
Likes
329
Location
France
This is a review and detailed measurements of the boXem Audio Arthur 4215/E1 mono power amplifier. It was sent to me by the company and costs €1,490.00.
View attachment 234484
The design is quintessential European with gray body and colorful front panel which I like. The only power button is on the back:
View attachment 234485
Fortunately you have trigger input so you can set it to power up when the source turns on. Three gain settings are provided which is very nice. Unlike some amps in its class, it has both XLR balanced and RCA unbalanced inputs.

The amplifier is class D and is based on Purifi 1ET7040SA module.

boXem Arthur 4215/E1 Measurements
I started with the input gain set to low:
View attachment 234486

This is superb performance and easily lands the unit in our top 5 amplifiers ever tested:
View attachment 234487
To get to full power with low gain, you need 9+ volts of input. So I set the amp to medium gain where 4 volts is enough to push it into clipping. Performance thankfully remains the same:
View attachment 234488

Signal to noise ratio is exceptional:
View attachment 234489

Low distortion translates into very high distortion-free dynamic range:
View attachment 234490

Frequency response is load independent and quite flat in audible band:
View attachment 234492

There is healthy amount of power available into 4 ohm:
View attachment 234493
View attachment 234494

Company asked me to also test 2 ohm performance:
View attachment 234495

We get the same low noise and distortion into 8 ohm:
View attachment 234496

There is some "ballooning" of the distortion curve at higher frequencies:
View attachment 234497

As noted, this is still very good for class d amplifier.

Conclusions
Building on solid foundation of Purifi amplifier module, the 4215/E1 delivers the goods with tons of power with very low noise and distortion. And it does so in a compact and attractive box with nice feature list. Not sure what else there is to ask for. Yes, the price is a bit high but you are getting European build and support so you need to value that as well.

It is my pleasure to recommend the boXem Arthur 4215/E1 amplifier.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I am glad to see that this Boxem amp based on a Purifi module displays stellar performances. It is a bit pricey but the stereo version dsiplays a much more competitive price while losing some features ( trigger and RCA inputs). However the autosense option ( automatic on/off switching ) and xlr inputs are still provided.
Congrats Boxem!
 

Axo1989

Major Contributor
Joined
Jan 9, 2022
Messages
1,052
Likes
904
Are those model numbers correct? I can see 4215/E2 and 4222/E1 (which looks like the mono 7040) both at €1490 on their product pages.
 

ririt

Senior Member
Joined
May 5, 2020
Messages
360
Likes
329
Location
France
Are those model numbers correct: I can see 4215/E2 and 4222/E1 (being the mono 7040) both at €1490 on their product pages?
Yes you are right. This is the reference provided by their web page. It is a bit confusing….Maybe Boxem can confirm which model has been tested by Amir and Amir, if needed, should correct the title of the review.
 

Matias

Major Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
3,696
Likes
7,080
Location
São Paulo, Brazil
Awesome amp!
 

Axo1989

Major Contributor
Joined
Jan 9, 2022
Messages
1,052
Likes
904
Yes you are right. This is the reference provided by their web page. It is a bit confusing….Maybe Boxem can confirm which model has been tested by Amir and Amir, if needed, should correct the title of the review.

Yes I noticed both web pages call themselves 4215. The text repeats 4222 consistently so I'm guessing that's it. It's not a drama either way, I'm sure it will get sorted.
 

ririt

Senior Member
Joined
May 5, 2020
Messages
360
Likes
329
Location
France
Yes I noticed both web pages call themselves 4215,.The text repeats 4222 consistently so I'm guessing that's it. It's not a drama, I'm sure it will get sorted
For sure no drama…especially on a sunny sunday morning here in the south of France! I am sure that Fred (the french Boxem´s owner) and Amir will fix it.
 

VintageFlanker

Major Contributor
Forum Donor
Joined
Sep 20, 2018
Messages
3,579
Likes
12,769
Location
Paris
Thanks, @amirm ! However, it is indeed Arthur 4222/E1. Not 4215.

Excellent job as usual, Fred ! :cool:
But I would have honestly expected a bit more... power...

Company asked me to also test 2 ohm performance:
BoXem Arthur 4222E1 Monoblock Amplifier Power into 2 ohm Measurement.png
So, 700W <1% THD+N. Great. It could be cool if this 2 Ohms load comes with any amp review, @amirm. ;)

Fortunately you have trigger input so you can set it to power up when the source turns on.
BoXem amps do have an auto-on feature as well.
 
Last edited:

capslock

Active Member
Joined
Jun 19, 2020
Messages
247
Likes
107
Now what is the 1ET7040SA module? The Purifi Audio homepage still shows only the 1ET400A module. Since I found no datasheet or even an announcement, I have no idea that niche this module is supposed to fill.

Is this taken from the Hypex playbook of introducing the NC400 flagship first and then following up with the slightly downspec'ed NC500OEM?
 
Top Bottom