boXem Arthur 4222/E1 Amplifier Review

[Phorize]

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).

If you don't mind me saying that's slightly contradictory. Sure, you can get the same basic performance for less, but I've never come across something costing half the price of this that is so thoughtfully featured and well put together. It's your vote but not terrible seems harsh IMO.

 

[Phorize]

In my opinion, there are both good reasons for, and against monoblock amplifiers. Single chassis stereo has advantages, just as dual chassis mono has considerable advantages.

There is no doubt however, if I was looking for a pair of Purifi mono implementations, these are the ones to buy. Your amplifiers will last you for decades, many decades, and coughing up for quality means you can focus on other things in life and just rest easy in the knowledge you decided to "buy once and buy well".

As it was said: 'The Bitterness of poor quality remains long after the sweetness of low price is forgotten’

Well done Fred.

Yep, IMO alot of the complaints about cost aren't considering that good product engineering costs money and constitutes value in its own right. These amplifiers look like they belong with a nice pair of speakers in a nice living room.

 

[VintageFlanker]

If you don't mind me saying that's slightly contradictory.

It is contradictory anyway. We are supposed to vote based on a product's overall performance. Period. Not performance relative to price, nor performance relative to competitors...
If a 20k€ DAC performs as good as 699$ Topping DX7 Pro, I would still vote great, because performance would be... great.

 

[charleski]

Bah, deleted, I read it wrong, it’s early on a Monday….

 

[boXem]

Does NAD use a different firmware?
Link

Since the article states that the current protection is at 22.5A instead of the standard 15A, I guess so.

Edit, to clarify, extracts from https://purifi-audio.com/wp-content/uploads/2020/01/1ET400A-Data-Sheet-1.00.pdf

We can see the effect of the OCP in the graph below

sqrt(450/2) = 15 A

This is the 1ET400A. Where the 1ET7040SA differs on the matter, is that the limit is set higher, with MOSFETS dimensioned to withstand this higher limit. So basically the current protection will not trigger in 2 Ohm.
Several people (not many to be clear) contacted me about the 4222/E1 with 1ET7040SA because they experienced the overload protection with a 1ET400A based amp mated to their high end speakers. The amp tested here is done for them and I believe that we should go back to it if you do not mind.

 

[Matias]

To me the irony is that Purifi chose to design the 1ET7040SA to have max power with a 70V power supply, when they have no power supply for it (yet). Maybe they could have designed it around 85V for the A700 version of the Hypex SMPS line.

We saw that the Purifi Eigentakt 1ET7040SA with 63V gives 750W in 2 ohms.
While the new Hypex NCoreX NCx500 with 85V gives 700W into 2 ohms, so quite similar.

AFAIK March Audio P501 is the only one using a 70V version of the Micro Audio SMPS1K-PFCR2 power supply to get these last amps to the full 950W in 2 ohms (even though the SMPS picture tries to hide it lol ).

 

[BadAudioAdvice]

@boXem | audio

Very nice looking amplifier. Clean and simple.

What would the performance of the amplifier look like if using high-gain and unbalanced RCA? How would it compare to the measurements at mid gain balanced?

 

[Ron Texas]

Nice amp with a catchy front panel. However, there are other Purifi based amps out there with similar performance for about half the price in a stereo package.

 

[boXem]

@boXem | audio

Very nice looking amplifier. Clean and simple.

What would the performance of the amplifier look like if using high-gain and unbalanced RCA? How would it compare to the measurements at mid gain balanced?

High gain is 29 dB, so a bit noisier. Distortion also slightly increases but stays far below noise level. So SINAD is around 96-97 dB. Same impact on SNR. I have an FFT plot somewhere but cant find it right now.

Other metrics do not change.

Nice amp with a catchy front panel. However, there are other Purifi based amps out there with similar performance for about half the price in a stereo package.

Would be curious to see a stereo 1ET7040SA based amplifier at half the price .

 

[heraldo_jones]

All the amps you are mentioning do not have the same power at 2ohm. You need a NC1200 for that, and please look at the prices.

As I said I don't know a speaker in the market with 2@ohm rating, name one if you can.

 

[Matias]

As I said I don't know a speaker in the market with 2@ohm rating, name one if you can.

My Thiel CS3.7 is not in the market right now, but it has a 2.7 ohm impedance most of the audio range...

 

[VintageFlanker]

As I said I don't know a speaker in the market with 2@ohm rating, name one if you can.

...

No speaker is rated at 2Ω nominal nowadays, but plenty do have minimal impedance at 3Ω and below.

 

[Fidji]

As I said I don't know a speaker in the market with 2@ohm rating, name one if you can.

Every electrostat.

 

[heraldo_jones]

...

Religion vs science ... Have luck believing in an invisible God

 

[dtaylo1066]

From a marketing standpoint, they would be wise to offer the faceplate in several different colors, including your standard black and silver. Not sure I would want to dole out 3,000 clams for a pair of bright orange amps. I love orange, but on golf shirts not amps.

Clearly a stellar performer, but has some less expensive Purify competition out there.

 

[Rja4000]

Yeah. Sure. No speaker goes down to 3-2 Ohms. Never. Thanks for your enlightenments.

And thanks for explaining to me what ASR is all about. I really needed it.

Dunning Kruger hits hard these days.

Peace, man
Ca ne sert à rien.

 

[amirm]

From a marketing standpoint, they would be wise to offer the faceplate in several different colors, including your standard black and silver. Not sure I would want to dole out 3,000 clams for a pair of bright orange amps. I love orange, but on golf shirts not amps.

Clearly a stellar performer, but has some less expensive Purify competition out there.

Multiple colors of faceplate are offered.

 

[boXem]

Multiple colors of faceplate are offered.

Cover can be light grey too, 6 combinations possible in total.

 

[boXem]

Yeah. Sure. No speaker goes down to 3-2 Ohms. Never. Thanks for your enlightenments.

And thanks for explaining to me what ASR is all about. I really needed it.

Dunning Kruger hits hard these days.

Peace, man

Ca ne sert à rien.

Je suis d'accord, pense à ton ptit cœur fragile .

 

[Matias]

From a marketing standpoint, they would be wise to offer the faceplate in several different colors, including your standard black and silver. Not sure I would want to dole out 3,000 clams for a pair of bright orange amps. I love orange, but on golf shirts not amps.

Clearly a stellar performer, but has some less expensive Purify competition out there.