boXem Arthur 4222/E1 Amplifier Review

[Fidji]

They went all in with external power supply for the modulator and the large discrete opamps from Weiss, while using the new fancier chassis... Price skyrocketed.

The Arthur 4222/E1 here is a lot more minimalist still keeping the module's excellent measurements and an impeccable build. Sure there will be even cheaper options in the near future, but to me this is a nice sweet spot in value.

Those Weiss Op-amps seem to be new audiophile darlings. Very popular with even very rational folks around here.

 

[fredoamigo]

Wow, so you have to buy two of these amps for a stereo setup which will be 3500 Euro in order to power your passive speakers - I suppose you gotta love passive speakers if you're going that route, lol! Do these offer enough power for "room sized" speakers, rather than "desktop speakers", they do right? Still expensive vs using active speakers.

If like me you really don't want to change speakers.
If like me you have passive speakers with a 15" so difficult to find in active and you do not want to end up with active speakers limited in size and SPL ( internal protection via the DSP) .
If like me, you want to have elements, modular, interchangeable, independently repairable, and possibly resellable at a fair price on the second hand market ... you do not choose active speakers ... it's a question of choice and freedom more flexible in my opinion but it is true that it is often more expensive.

 

[boXem]

Those Weiss Op-amps seem to be new audiophile darlings. Very popular with even very rational folks around here.

Well, one has to admit that they have exceptional performance.

 

[AndreaT]

Well, one has to admit that they have exceptional performance.

Weiss engineering offers superb assistance to individuals, as I found out when the CD reader of my MAN301 stopped working. I can imagine the same happens for corporate customers.

 

[ex audiophile]

I think it's misleading to focus only on SINAD when comparing "performance" of amplifiers. I thought having an abundance of "clean power" was the over arching goal. Would it be better to choose a solid A/B amp like for example the Anthem MCA225 which offers 225/400/600 with a manufacturer's SNR of 120? It would be cheaper than a pair of these monoblocks. In particular isn't the "burst power" a very important factor when considering music peaks? It appears these D amps don't have much to offer above their cited power rating. The Anthem STR power amp offers a burst power of about a kilowatt. Yes of course it's a pricey amp but I've kept mine because of it's power capabilities, even though its SINAD is not in the upper echelon. Can we really hear differences between amps with SINAD of 90 and above? I'm not an Anthem salesperson, it's just the brand I'm most familiar with. And I'm only suggesting we consider factors other than a couple points of SINAD in the rating chart when assessing amps.

 

[AndreaT]

I think it's misleading to focus only on SINAD when comparing "performance" of amplifiers. I thought having an abundance of "clean power" was the over arching goal. Would it be better to choose a solid A/B amp like for example the Anthem MCA225 which offers 225/400/600 with a manufacturer's SNR of 120? It would be cheaper than a pair of these monoblocks. In particular isn't the "burst power" a very important factor when considering music peaks? It appears these D amps don't have much to offer above their cited power rating. The Anthem STR power amp offers a burst power of about a kilowatt. Yes of course it's a pricey amp but I've kept mine because of it's power capabilities, even though its SINAD is not in the upper echelon. Can we really hear differences between amps with SINAD of 90 and above? I'm not an Anthem salesperson, it's just the brand I'm most familiar with. And I'm only suggesting we consider factors other than a couple points of SINAD in the rating chart when assessing amps.

Well…SINAD is probably an important measure of careful design and implementation of what is possible. Reliability is another factor, more difficult to grade except in those spectacular frequent failures reported here in ASR. While philosophically it is possible to imagine a compromised product with a splendid SINAD, in my limited, but extended over a few decades, experience, amplifiers well behaved in S/N ratio and harmonic distortion do sound better to my ears in a wide variety of music. I did first discover how amps could make a difference a long time ago when listening (in a quiet room during a quiet time) to The Dark Sound of the Moon in a Hi-Fi show exhibit: the already well known LP offered new and more involving experience when played through the Mark Levinson mono blocks. My home amplifier was then a Dynakit ST-35, likely to have a (much) lower SINAD than the ML.

 

[Fleuch]

Wow, so you have to buy two of these amps for a stereo setup which will be 3500 Euro in order to power your passive speakers - I suppose you gotta love passive speakers if you're going that route, lol! Do these offer enough power for "room sized" speakers, rather than "desktop speakers", they do right? Still expensive vs using active speakers.

Absolutely love the Boxem product finish, but with the cost of 1743 Euro each - well, the Benchmark AHB2 is a serious contender AND for less Euros. Sorry Fred, but at that price level there is serious competition.

 

[fredoamigo]

Absolutely love the Boxem product finish, but with the cost of 1743 Euro each - well, the Benchmark AHB2 is a serious contender AND for less Euros. Sorry Fred, but at that price level there is serious competition

The Benchmark AHB2 is a bridgable stereo amp and in Europe it sells for 3699 € each which puts the two at over 7000 € if you want to have equal performance to the Boxem mono

 

[thin bLue]

Nice SINAD and Multitone!

But, It looks little odd to me.
1ET7040SA should produce way more power.

1ET400A would be roughly enough for that application. With little bit better SINAD, Noise and lower cost.

Yes, If you decide to use 1ET7040SA, it should do way more than 1ET400A.

IMHO, With this amp, it is better to use 1ET400A or Improved Power ssupply capable to fully feed the 1ET7040SA.

 

[F1308]

A little pricey but that performance more than compensates for those that want it. Should be able to tame just about any beast of a speaker.

A little pricey times two, being monophonic.
2980 € then.

 

[Rja4000]

Improved Power ssupply capable to fully feed the 1ET7040SA.

Well, this IS an improved power supply, compared to the 1ET400. You have the power for 2 channels available for 1.
If that's not improved...

 

[boXem]

Nice SINAD and Multitone!

But, It looks little odd to me.
1ET7040SA should produce way more power.
View attachment 234666
View attachment 234668
1ET400A would be roughly enough for that application. With little bit better SINAD, Noise and lower cost.

Yes, If you decide to use 1ET7040SA, it should do way more than 1ET400A.

IMHO, With this amp, it is better to use 1ET400A or Improved Power ssupply capable to fully feed the 1ET7040SA.

How much is "way more power"? 70 W?

What other power supply? As of now I am only aware of the SMPS1200 being adequate for this module. Other need capacitor banks or lack safety certifications, or are unavailable.

Compared to the 1ET400A the advantage of the 1ET7040SA is in low loads, not at 4 Ohm.

 

[nothingman]

Nice SINAD and Multitone!

But, It looks little odd to me.
1ET7040SA should produce way more power.

That’s what I was thinking too. Why does this fall short of the spec in a mono config with massive power supply?

 

[nothingman]

How much is "way more power"? 70 W?

What other power supply? As of now I am only aware of the SMPS1200 being adequate for this module. Other need capacitor banks or lack safety certifications, or are unavailable.

Compared to the 1ET400A the advantage of the 1ET7040SA is in low loads, not at 4 Ohm.

E.g. 1% THD+N into 4ohm, Amir measures 398w and eyeballing the Purifi graph it should be more like 500w. I’m not saying that’s a big difference in dB but why does the unit fall short at all given the build and price?

 

[KMO]

Well, this IS an improved power supply, compared to the 1ET400. You have the power for 2 channels available for 1.
If that's not improved...

But it is short in voltage to get the full specified power for the 1ET7040SA.

The 1ET400A is rated for a 65 V supply, and most builds use the 63 V Hypex supplies, which is a little low, but not much.

The 1ET7040SA is rated for a 70 V supply - the 63 V supplies are beginning to look a bit inadequate.

There's a graph in the 1ET7040SA datasheet showing the impact of a lower supply:

Reading that off, at the full 70 V you'd get 250W/500W/925W.
At 63 V you should be getting 200W/400W/750W, which I believe is roughly what Amir measured here.

 

[oivavoi]

monaural amplifiers can advantageously be put right next to the loudspeakers, thus decreasing the influence of loudspeaker cables to almost nothing.

Not related to Boxem specifically, but is there any evidence - from measurements or controlled listening tests - that long cable runs are bad? As long as we're talking domestic applications here, not 50 meters in noisy pro environments.

 

[boXem]

That’s what I was thinking too. Why does this fall short of the spec in a mono config with massive power supply?

As written before, the curves extracted from the leaked Purifi specification are with +/- 70V rails. We use a power supply with +/-63V rails, because it is the one that better fits the bill.

 

[thin bLue]

Well, this IS an improved power supply, compared to the 1ET400. You have the power for 2 channels available for 1.
If that's not improved...

1ET400A is an Amplifier unit not a Power supply unit.

I'm talking about how to get real world power that you mentioned in your comment!

 

[mocenigo]

2 of these cost 1500 EU tax included, more than twice the price for a few extra watts is wild.

The real difference is below 4 ohm. There the 7040 based amp can deliver MUCH MORE and it is also stable down to 1 ohm or something. So that's where there it difference. The additional power at 4 or 8 ohm is, well, almost unnoticeable in practice. So this amp makes sense only if you have to drive hard speakers. In which case it does make a difference.

 

[nothingman]

Interesting. I didn’t realize the 1200 would be short on voltage.

Just as a layman, I find it really odd Purifi hasn’t come up with a 70V supply by now and is relying on Hypex to supply basically the whole market. Is a 70V supply a very hard thing to make? The 400A is underserved as well by a little, but now the 7040SA is being delivered even further from its potential. The boXem unit is no doubt impressive, just seems weird Purifi isn’t making it the best it can be.