• 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 2408/N2 Teardown (Class D Amp)

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
37,367
Likes
156,041
Location
Seattle Area
I recently reviewed the boXem ARTHUR 2408/N2 class D stereo amplifier. This is a follow up teardown of the unit. A handful of screws keep the case together making it easy to take apart:
boXem ARTHUR 2408 N2 Teardown Class D Stereo Amplifier.jpg


I must stay, this is a beautiful looking build. Starting with power plug, we see the whole thing has been covered with heatshrink tube, highly minimizing the danger of terminals coming loose and making connection to the chassis. A proper earth safety terminal is connected to bare chassis as it should be.

The amplifier has auto turn-on so a sense board is used to detect the signal from the XLR connectors to the input of the Hypex NC122MP which is a combination stereo amplifier and switching power supply. Paint/anodization has been removed from most of the chassis to allow for better heat transfer. Many holes are drilled which increase the surface area of the case to allow better convection cooling.

Output wires are tidy and go the shortest distance to the speaker terminal and kept away from each other, aiding in its great crosstalk measurments. Likely that custom board helps with that as well.

Cable for the front panel clipping and power on indicator has been nicely tie wrapped to the case rather than using stick on clamps which come unglued easily.

Everything within the control of the builder has been done to create a nice and clean amplifier around that Hypex module from safety and performance point of view.

Conclusions
It is easy to dismiss the roll of companies building amplifiers around these hypex modules. Yet we usually see a lot of missteps which potentially make the devices less safe and performant. The opposite is the case here. Clearly the designer paid attention to everything including adding custom modules/features to make the device more than just the bare amplifier. This is a model of how it should be done.

-----------
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/
 

Xyrium

Addicted to Fun and Learning
Forum Donor
Joined
Aug 3, 2018
Messages
531
Likes
448
So, is that board with "Boxem Audio" on it, simply an IO board, connecting the amp module to the output?

Edit: ...and is the silver under the boards a large strip of aluminum tape, or is the case unfinished in that area?

Thanks!
 

boXem | audio

Major Contributor
Manufacturer
Forum Donor
Joined
Jun 19, 2019
Messages
1,417
Likes
2,570
Location
Europe
So, is that board with "Boxem Audio" on it, simply an IO board, connecting the amp module to the output?

Edit: ...and is the silver under the boards a large strip of aluminum tape, or is the case unfinished in that area?

Thanks!
Yes, it is an io board.
First version of the case was fully painted but my tests shown that the isolation layer created by the paint was creating some thermal issues with higher powered amps. So goodbye paint.
 

enricoclaudio

Senior Member
Manufacturer
Joined
Jan 7, 2021
Messages
432
Likes
663
WOW.. It looks clean and neat in and out. Very well done, @boXem | audio !!!
 

Digital Mastering System

Active Member
Forum Donor
Joined
Jan 3, 2020
Messages
121
Likes
143
Location
MN
I too am very impressed. All the Dutch engineers I 've worked with (at Philips) have impressed me with their skill and knowledge. The Boxem ARTHUR 4215/E2 is what I would like to see tested; it is built exactly as I would do it, with OPA1656s and high power Purifi modules (if I could get them). I have always planned on building a Purifi amp, but now I see Boxem has built the one I want: ARTHUR 4215/E2.
 

trl

Major Contributor
King of Mods
Joined
Feb 28, 2018
Messages
1,743
Likes
1,871
Location
Iasi, RO
Totally love the inside guts.

I've also seen ARTHUR 4215/E2 that benefits of an adjustable gain, so I'd love to see it "in action" on Amir's desk. I think that it may measure better than 2408 on the lowest gain (also, probably the different NCore modules will help a bit here as well).
 

TimoJ

Active Member
Joined
Dec 9, 2019
Messages
271
Likes
233
Location
Finland
Starting with power plug, we see the whole thing has been covered with heatshrink tube, highly minimizing the danger of terminals coming loose and making connection to the chassis.
That is not heatshrink tube, it's a rubber insulation boot made specially for IEC connectors. Various models are available, highly recommended also for DIY builds.
 

restorer-john

Master Contributor
Joined
Mar 1, 2018
Messages
8,731
Likes
24,238
Location
Gold Coast, Queensland, Australia
That is not heatshrink tube, it's a rubber insulation boot made specially for IEC connectors. Various models are available, highly recommended also for DIY builds.

Yes, there is a single IEC boot, plenty of heatshrink on the ends of every loom/cable and runs of PET expandable woven flex sleeve.

The only thing that seems odd is the two screws and spacers missing on the input/wake board. We can see Amir's white light showing through, so we know there's holes lined up. @boXem | audio probably decided they weren't needed as the pin header and XLR screws were sufficient I guess.
 

boXem | audio

Major Contributor
Manufacturer
Forum Donor
Joined
Jun 19, 2019
Messages
1,417
Likes
2,570
Location
Europe
Yes, there is a single IEC boot, plenty of heatshrink on the ends of every loom/cable and runs of PET expandable woven flex sleeve.

The only thing that seems odd is the two screws and spacers missing on the input/wake board. We can see Amir's white light showing through, so we know there's holes lined up. @boXem | audio probably decided they weren't needed as the pin header and XLR screws were sufficient I guess.
Not only it is sufficient, but using the additional screws created a stress on the connector solder that didn' t make me confident on long term reliability.
 
Top Bottom