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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 17.0%
  • 4. Great (golfing panther)

    Votes: 274 77.6%

  • Total voters
    353

mocenigo

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I now also voted not terrible. There are amps at half the price (or even less) measuring very similar. My vote never goes for performance, but for the compendium of the entire product (unless the product is a killer one, and this is not).

Which amps are half price or less, measure very similarly, AND have a similar power also at 2ohm?
 

fpitas

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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 further from its potential. The boXem unit is no doubt impressive, just seems weird Purifi isn’t make it the best it can be.
Historically 70V service is for institutional sound systems like schools etc., where the speakers are ceiling mounted, with a low performance 70V transformer attached.. There may be high fidelity applications, but I'm not familiar with any.
 

thin bLue

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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.
with 1ET7040A, I expect at least 1% 950W @2 ohms.

What power supply?
I don't know.

Don't get me wrong. I'm not a producer of this kind of products, and not belong to company make AMP/PSU thing right now.

So, That's concern of makers not consumers. you should figure out your self. Consumers like I myself only concerns about real world out put power the amp produces.
 

thin bLue

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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.
With delicate analyser, we can "see" the difference, with ears, we can't "hear" any differences.

Of course with normal cables.
 

fredoamigo

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So this amp makes sense only if you have to drive hard speakers. In which case it does make a difference.
not only, in a general way, you have to choose an amplifier able to provide the power you need before it approaches clipping and this one arrives faster than we think whatever the load and when you are in the zone close to clipping, the distortion values are often unpredictable. That's why the fact of choosing an amplifier "oversized" beyond the dynamic range etc. etc. has a sense in my opinion
 

Fleuch

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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
Copying the text from https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier

Continuous Average Output Power
  • < 0.0003 % THD+N at full rated power, 20 Hz to 20 kHz
    • 100 Watts per channel into 8 Ohms, both channels driven
    • 130 Watts per channel into 6 Ohms, both channels driven
    • 190 Watts per channel into 4 Ohms, both channels driven
    • 240 Watts per channel into 3 Ohms, both channels driven
    • 200 Watts into 16 Ohms, bridged mono
    • 380 Watts into 8 Ohms, bridged mono
    • 480 Watts into 6 Ohms, bridged mono
This suggests the AHB2 is a two channel stereo amplifier, and is not exclusively for use in BTL mode

Also the photograph of the back panel at https://www.scvdistribution.co.uk/product/benchmark-ahb2-high-res-amplifier-black clearly shows two input channels, which can also be found in the AHB2 manual

The manual contains the following:

Bottom Row, Left to Right:
• 12 Volt Trigger Input / Output Connector
• 3-Position Sensitivity Switch - Sets Gain
Balanced XLR Input for Channel 2
• NL4 Speaker Output for Channel 2
• NL4 Speaker Output for Bridged Mono Operation
• NL4 Speaker Output for Channel 1, or Channels 1 and 2
Balanced XLR Input for Channel 1, or for Bridged Mono
• 2-Position Mode Switch - Enables Bridged Mono Mode
• 12 Volt Trigger Input / Output Connector

The cost of the AHB2 in the UK is £3249 (including VAT) so for a two-channel, non-bridged configuration the comparison with two Boxem monoblocks is reasonable.
 

mocenigo

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not only, in a general way, you have to choose an amplifier able to provide the power you need before it approaches clipping and this one arrives faster than we think whatever the load and when you are in the zone close to clipping, the distortion values are often unpredictable. That's why the fact of choosing an amplifier "oversized" beyond the dynamic range etc. etc. has a sense in my opinion

Well, that's what I do. I designed my speakers (Fred has heard them) with a very gentle impedance (always over 5.6Ohm, almost always over 8 Ohm, very contained phase rotations) without getting too crazy for ruler flat response - even though 100hz-18khz is within +-2.5Db of 97.5Db/w/m. But even in this case, I am using Purifi 1ET400A modules. Since my PSU is 60V, at 8 ohm I am speaking go 165W tops, and on this load it will probably not go over 140-150W. But even if a listen at a few deciWatts normally, percussion instruments can easily be 20-30Db above the floor for an extremely short period of time. Which is 100x to 1000x the power. Hence, having an amp that can deliver that with aplomb means actually dynamics.
 

Rottmannash

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What would the power look like measured @ high gain?
 

Fleuch

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PS: the AHB2 may require a BTL configuration to achieve the same power output as two Boxem monoblocks but power is not the only performance criteria. Agreed if power was the sole criteria the Boxem would run rings around four AHB2's at around £13,000.
 

boXem

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with 1ET7040A, I expect at least 1% 950W @2 ohms.

What power supply?
I don't know.

Don't get me wrong. I'm not a producer of this kind of products, and not belong to company make AMP/PSU thing right now.

So, That's concern of makers not consumers. you should figure out your self. Consumers like I myself only concerns about real world out put power the amp produces.
Well, since you are the voice of the consumer, you should be happy to see that the measured performance here is consistent with the one published on our site.
 

AudioSceptic

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PS: the AHB2 may require a BTL configuration to achieve the same power output as two Boxem monoblocks but power is not the only performance criteria. Agreed if power was the sole criteria the Boxem would run rings around four AHB2's at around £13,000.
But if you operate a stereo amp in bridged mono, don't you lose low impedance power ability?
 

sarumbear

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Who voted not terrible? :facepalm:
This is the top 10 best performing (in terms of SINAD) amplifier that we have measurements for...not to mention 4th best reviewed by Amir so far.

Courtesy of @Matias spreadsheet
We already have three terrible votes :facepalm:
 

57gold

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So, is there a +/- 70V power supply available to achieve Purifi spec output, if one was looking for more power?

Currently using a McCormack DNA-500 that has been in service for 25 years, 500 watts into 8 Ohms and 900 watts into 4 Ohms. Aerial 10Ts respond well to power/current, deep, controlled, pitch-specific bass. But at 25 years, need a very high powered alternative and have been watching the roll out of this new Purifi high powered module as a solution to the day the DNA-500 gives up the ghost.

Believe I read about a new, high powered/current Hypex module in the works...
 

sarumbear

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Exactly. Every good quality multimeter and all test equipment follows the correct spacing.View attachment 234605
Though I never see the reason to apply the same distance for speaker connections. Just because they are using banana plugs? They are now even illegal in some regions. 19mm is too small to bind speaker cables.
 

thin bLue

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Well, since you are the voice of the consumer, you should be happy to see that the measured performance here is consistent with the one published on our site.
And that's the reason why I don't have to choose them.

I'm not happy to see that the measured performance here is not consistent with the one published on Purifi's official specification sheets.


I thought you have enough skills to improve them and make every more happier. but it seems you don't have any willings to do that.



This is my 1et400a based streo amp, single channel driven, 2 Ohms
1662377961491.png


and yours, 1ET7040SA based monoblock amp, 2 Ohms
BoXem Arthur 4222E1 Monoblock Amplifier Power into 2 ohm Measurement.png


I can't justify to buy '2nd one' as my way of thinking at this moment. Can you?

Why make good looking chassis and every nice points of your products less meaningful with that PSU?
 

DonR

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A little pricey times two, being monophonic.
2980 € then.
Yes, but monoblock is preferable given its intended application, high current into difficult loads. Personally, I am happy with 100W/channel and anything better than 85db SINAD. As my speakers are 6-ohm minimum I don't require anything exotic so in my case about $1000 is sufficient and anything else is pricey. YMMV but diminishing returns is a very steep hill.
 

F1308

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Yes, but monoblock is preferable given its intended application, high current into difficult loads. Personally, I am happy with 100W/channel and anything better than 85db SINAD. As my speakers are 6-ohm minimum I don't require anything exotic so in my case about $1000 is sufficient and anything else is pricey. YMMV but diminishing returns is a very steep hill.
I am truly satisfied with my Topping PA5 !!!!
 
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