boXem A 4216/E2 Stereo Amplifier Review

[amper42]

1. Either Boxem Arthur or A Series Purifi stereo design works great.
2. The "A" series - A 4216/E2 design is a bit more cost efficient while also offering SpeakOn.
3. "A" series offers Top mounting/ventilation approach with a two stage buffer.
4. Arthur offers standard bottom mount with premium 3-stage buffer.
5. Both use Purifi 1ET6525SA and Hypex SMPS1200
6. A 4216/E2 measures 233 x 87 x 299 mm while Arthur 4216/E2 is 224 x 80 x 318 mm

You are correct there are a lot of Boxem variations available from mono to stereo to Purifi to Hypex NCx500.
Perhaps, more choice makes the decision difficult?
Once you see the "A" Series as evolution in the product line up and realize all the models are simply Purifi or Hypex NCx500 based it's pretty easy to navigate.

Purifi efficiency is so high that Heat is never an issue so I'm not sure the top mount offers as much function with Purifi as NCx500.
While I like the Arthur design, the SpeakOn connectors in the A 4216/E2 would drive my next purchase.

However, what I would really like is the 3-stage buffer with SpeakOn in the A 4216/E2 case.

 

[boXem]

Hope that helps.

Yes it does, a lot. Thanks!

 

[antcollinet]

Yes it does, a lot. Thanks!

Just for fun, I asked Chat GPT to take a look for me.

Prompt:

Hi I am looking a the Boxem Amplifier website:

boXem | audio - Index

HiFi made in Luxembourg

boxem-audio.eu

I am struggling to get an over view of the different models. Can you:

1 - Describe the headline differences between the Arthur and A Series ranges.


2 - For each range, create a table showing the headline specifications for each model.

Result in the attached PDF - I have no idea how accurate it is.

 

[boXem]

@antcollinet & @dan_uk , some changes following your suggestions:
- explanation of the differences Serie A - Arthur on the front page

- Implementation of a filtering system:

Major site overhaul is planned, if you have other suggestions, they are welcome, we will implement them at this time.

 

[amper42]

At what point, does lower input impedance make a difference? Would you expect any noticeable difference between an amp with 8.4k ohms impedance versus one with 47K? Thank you!

 

[boXem]

It depends from the upstream component. A tube based output stage will probably not like anything below 20k per leg, so 40k differential.

 

[antcollinet]

It depends from the upstream component. A tube based output stage will probably not like anything below 20k per leg, so 40k differential.

Glad you mentioned that. It's never been clear to me (in general - not just your specs).

When a balanced input is given an impedance spec - is that normally a differntial impedance, or a "per leg" impedance? And is this an industry standard - so that all manufacturers use the same definition?

Thanks.

 

[antcollinet]

some changes following your suggestions:

Front page is much better - though I'd suggest pretty-fying it during your major overhall.

But the amp pages seem to have gone wrong. I'm getting no amplifiers listed no matter what filter settings I use (see screenshots), or which range I view. This is on Safari on Mac. EDIT - also just tried on Brave (Google chrome based) with the same result.

 

[boXem]

Glad you mentioned that. It's never been clear to me (in general - not just your specs).

When a balanced input is given an impedance spec - is that normally a differntial impedance, or a "per leg" impedance? And is this an industry standard - so that all manufacturers use the same definition?

Thanks.

It is dependant from the topology of the connected output.
If it is two active components working in opposition of phase, each one will see the impedance of a single leg.
If it is a single active component, it will see the differential impedance. So in this case, for a tube based output, matching to a 20k differential input impedance would be ok.

Front page is much better - though I'd suggest pretty-fying it during your major overhall.

But the amp pages seem to have gone wrong. I'm getting no amplifiers listed no matter what filter settings I use (see screenshots), or which range I view. This is on Safari on Mac. EDIT - also just tried on Brave (Google chrome based) with the same result.

View attachment 506516 View attachment 506517

Ah... The IIWDNTA rule proves to be right once again. Will have a look.

 

[antcollinet]

It is dependant from the topology of the connected output.

Ah - I didn't explain my question very well. What I am unsure of:

When you state your amp has a 47k impedance on its balanced input, is that 47k differential, or 47k per leg (94k differential)? And is your definition of that an industry standard used by all manufacturers?

Thanks.

 

[boXem]

Front page is much better - though I'd suggest pretty-fying it during your major overhall.

But the amp pages seem to have gone wrong. I'm getting no amplifiers listed no matter what filter settings I use (see screenshots), or which range I view. This is on Safari on Mac. EDIT - also just tried on Brave (Google chrome based) with the same result.

View attachment 506516 View attachment 506517

Tested OK with half a dozen of browsers based on Wabkit, Chromium and Mozilla on Windoze, Linux and Android. Or it's an Apple specific issue, or you were unlucky. Clearing cache may help.

Ah - I didn't explain my question very well. What I am unsure of:

When you state your amp has a 47k impedance on its balanced input, is that 47k differential, or 47k per leg (94k differential)? And is your definition of that an industry standard used by all manufacturers?

Thanks.

It is differential. And there was a typo since it is indeed 94k.

 

[antcollinet]

Tested OK with half a dozen of browsers based on Wabkit,

That's odd. Just cleared cache in safari - same result. Tried google chrome (almost never used so not been to your site before).

EDIT just completely cleared the chrome cache - same result.


I'm on my way out now, but later will check with a windows virtual machine I have, an old macbook, and the Tor browser to check for location issues.

 

[amper42]

I'm on Boxem site now and none of the product is populated.
It says: "No products available yet".
This is the same under:
Arthur
A Series
Accessories

The only way I can see anything is clicking on the Boxem logo. Otherwise, no product is loaded.
You can see filters if you click Mono or Stereo but clicking them shows no product.

For all practical use, the BOXEM site has been down now for the last 24 hours from product viewing.

Mono Amplifiers

boxem-audio.eu

 

[Sokel]

Ah - I didn't explain my question very well. What I am unsure of:

When you state your amp has a 47k impedance on its balanced input, is that 47k differential, or 47k per leg (94k differential)? And is your definition of that an industry standard used by all manufacturers?

Thanks.

That's the usual way of reporting it:

Audio input shield to ground must be stated, also (it's usually at the 10 Ohm-100 Ohm ballpark)

 

[Fledermaus]

A detail, but while we're at it : the A series menu displays nicely in English

Not so much en français, where the multichannel vanishes (Mozilla/Windows) :

That being said, navigating and filtering options within each subcategory seems to work fine as for now.

 

[boXem]

I'm on Boxem site now and none of the product is populated.
It says: "No products available yet".
This is the same under:
Arthur
A Series
Accessories

The only way I can see anything is clicking on the Boxem logo. Otherwise, no product is loaded.
You can see filters if you click Mono or Stereo but clicking them shows no product.

For all practical use, the BOXEM site has been down now for the last 24 hours from product viewing.

Mono Amplifiers

boxem-audio.eu

Are you also browsing from an Apple product?

That's the usual way of reporting it:

View attachment 506597

Audio input shield to ground must be stated, also (it's usually at the 10 Ohm-100 Ohm ballpark)

That's ICE's way of reporting it. Hypex and Purifi do it a different way, and most end product manufacturers only report the differential impedance.
In our case, shield is shorted to chassis GND, which allows the best EMI behavior.

A detail, but while we're at it : the A series menu displays nicely in English

View attachment 506594


Not so much en français, where the multichannel vanishes (Mozilla/Windows) :

View attachment 506596

That being said, navigating and filtering options within each subcategory seems to work fine as for now.

Yeah, that's one of the reasons of the needed major overhaul. There are two much bigger bugs on the same page (apparently 3 now), one visible by end users, but I am not owner of the code so we have to live with it until we migrate to something else.

 

[Sokel]

In our case, shield is shorted to chassis GND, which allows the best EMI behavior.

That's the best universal way to do it for the device of its own, totally agree.

But I suspect ice reads lots of diyaudio* as it does it "separating" the analog ground from the logic ground (for report and control, both analog and digital, it's packed) at the input, only to tie to the ground after the R/C, near the outputs.

* the diode bridge to ground is a classic along with some resistance at the input for supposed "immunity". I don;t blame them though, since the specific higher power modules are put to subs or pro stuff, often mixing and matching, some short of break is needed.

 

[amper42]

Are you also browsing from an Apple product?

Yes, Apple MacBook Pro, MacBook Air, iPhone all show the same. Boxem site totally unusable...
On the bright side only 40% of the internet uses an apple product for browsing now...

 

[Soniclife]

Yes, Apple MacBook Pro, MacBook Air, iPhone all show the same. Boxem site totally unusable...
On the bright side only 40% of the internet uses an apple product for browsing now...

View attachment 506608

It's not working for me on android, tried chrome, opera and brave.

 

[boXem]

It's not working for me on android, tried chrome, opera and brave.

From which country if I may?