Audiophonics HPA-S400ET Review (Stereo Amplifier)

[Bob101]

Our hobby is not so rational all the time….

That statement is one that anyone should hold printed largely in bold typeface somewhere close near your listening space.

 

[Bleib]

This has now been discontinued but a new version soon to be released

AUDIOPHONICS HPA-S450ET Power Amplifier Purifi 1ET6525SA

The Audiophonics HPA-S450ET power amplifier is based on a Class D architecture, using a pair of Purifi 1ET6525SA amplification modules, a Hypex SMPS1200A400 power supply and an Audiophonics custom buffer stage...

www.audiophonics.fr

And the cheaper version:

AUDIOPHONICS LPA-S450ET Power Amplifier Stereo Purifi 1ET6525SA

We're proud to present the Audiophonics LPA-S450ET, a Class D stereo power amplifier based on two Purifi 1ET6525SA modules. Electronically similar to the HPA-S450ET, this version is housed in a more compact case...

www.audiophonics.fr

And 3 channel version:

AUDIOPHONICS HPA-T450ET Power Amplifier 3 Channels Purifi 1ET6525SA

The Audiophonics HPA-T450ET power amplifier is based on a Class D architecture, using three Purifi 1ET6525SA amplification modules, a Hypex SMPS1200A400 power supply and an Audiophonics custom buffer stage...

www.audiophonics.fr

 

[Hagan66]

This is a review and detailed measurements of the Audiophonics HPA-S400ET. It was sent to me by the company after member request and costs 1 490,00 € (US $1,638).
View attachment 194285

I must say this is one of the best packaging of class D amplifiers (Purifi in this case) that I have seen! It is slick and has style. While the heatsink on one side is cosmetic, the other is connected to the power supply power transistors although in use nothing rose above room temperature. Back panel shows extremely high quality speaker connections:
View attachment 194286
You can see it better with the lid open:
View attachment 194287

I must say, this is so clean you can eat of of it! I simply cannot find any fault with the assembly and design. Bottom to modules are Purifi 1ET400A modules fed by their own custom buffer/pre-amp gain stage. Jumpers let you select from different settings (see measurement section).

Audiophonics HPA-S400ET Measurements
Given the three different gain stages, it was a challenge to decide what to test so that this job doesn't become nearly infinite in scope. I will first show you the dashboard for all three gains starting from high gain:
View attachment 194288

This is superb performance already with distortion products at -125 dB. Channel matching is excellent. Here is medium gain petformance:

View attachment 194290

This is a nice setting as max power is achieved at 4 volts meaning you can use all of our modern/desktop amps to drive the unit and gain a bit of performance.

If you have a pro interface that goes up to 10 volts out, you can utilize the low gain mode:
View attachment 194291

This gain is actually close to how I measured our two top performers (Benchmark AHB2 and Topping PA5) so let's see how the Audiophonics ranks:

View attachment 194292

Looking at top 20 we see:
View attachment 194293

Amazing performance! Measuring SNR at low and medium gain we get:

View attachment 194294

View attachment 194295

OK, from here on I am going to stick with low gain mode. Here is our multitone:
View attachment 194296

Stellar as expected. Crosstalk manages to actually land in #1 position of any amplifier tested:

View attachment 194319
Frequency response is dead flat with no load dependency:
View attachment 194298

Let's sweep and see how we do with 4 ohm load:
View attachment 194299

Excellent performance. Here is how much power we get if we allow more distortion:
View attachment 194300

Switching to 8 ohm we see that the performance actually exceeds than of Purifi (although I think that was tested at higher gain):

View attachment 194301

Testing at other frequencies we still have great performance:

View attachment 194302

Finally, the amplifier is stable at power up so no need to wait for it to warm up:
View attachment 194303

Conclusions
The Audiophonics HPA-S400ET comes in a beautiful package with super performance to match its good looks. Yes, it builds on Purifi's excellent platform but they managed to add value without messing with its performance. The gain settings are well thought through. The whole thing is so well executed and must be a delight to our European members who can buy it locally. Having been built in France, it is also a feather in the cap of our French members.

I am happy to give my strongest recommendation to Audiophonics HPA-S400ET. You have a lot of power with superb fidelity and transparency.

Edit: video review just posted:

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Yeah. But what about the sound quality

 

[mike70]

Yeah. But what about the sound quality

What is "sound quality" for you? What you listen in your room with your acoustics / speakers / sources? That`s not the sound quality of the amplifier, that`s the result in YOUR room and with YOUR taste.

What the review shows is what you really need to know about the amplifier, stuff like ... is transparent to the source? power available?
If the amplifier (as an electronic device) have the technical requirements you need, then you can EQ / tinker as you want.

That's all. There's no magic goblins inside an electronic circuit and the technology to make a very good amplifier in the 21th century is no magic also.

 

[Overseas]

Yeah. But what about the sound quality

What about (your) ear quality, huh!?

Amplifiers are made by engineers, you know... yeah, shock and awe...

 

[AweLoi]

Yeah. But what about the sound quality

Sound is quality is stellar. Clean, effortless, smooth and very musical. It just get out of the way really.

 

[mocenigo]

Yeah. But what about the sound quality

Come on, if "66" is your birth year, you are too old to play troll.

 

[PloddyPastard]

Come on, if "66" is your birth year, you are too old to play troll.

Agree....specifically looking at the post he made 15 mins ago

Nord's new Value-Line Hypex NCore MP series

, but still for me it’s a bit of of leap of faith as I have no opportunity to hear one before I spend a lot of money. Remember that Nord has a 14 day money back guarantee, worst case you would lose some restocking fee and shipping back, no big deal to try one yourself.

audiosciencereview.com

 

[Hagan66]

Come on, if "66" is your birth year, you are too old to play troll.

Sorry man. Forgot to finish previous post with ;-) That said....it occured to me recently that we slate folks on here, in general (and quite correctly) for their subjective bullshit re so called various aspects of SQ. But then, after a smoke admittedly, it occured to me that could folks here tell, with properly double blinded, sound level matched tests etc, equipment that measured well with equipment that measured shit. Genuinely not trying to be controversial, but would be interested in your reply. I'm just a curious amateur don't be taking too seriously, or seriously at all which I'm sure you are not!! I have a first class honours degree in a scientific subject but not one with any relevance to hifi engineering or sound measurement...

 

[pma]

But then, after a smoke admittedly, it occured to me that could folks here tell, with properly double blinded, sound level matched tests etc, equipment that measured well with equipment that measured shit

Speaking about normally designed solid state amplifiers, one with THD+N of -90dB, the other with -120dB, none of them clipping with the music sample used for test, and in a properly done DBT - no one will tell a difference, I am 100% sure. You know, that chase for ultra low distortion number is just a kind of a hobby only, for those who do not know it only creates another myth, another golden calf.

 

[mocenigo]

Sorry man. Forgot to finish previous post with ;-) That said....it occured to me recently that we slate folks on here, in general (and quite correctly) for their subjective bullshit re so called various aspects of SQ.

Do not worry. I was purposefully not blasting you. My tone was a bit condescending, which is also wrong, but I hope I did not descend into bad manners.

But then, after a smoke admittedly, it occured to me that could folks here tell, with properly double blinded, sound level matched tests etc, equipment that measured well with equipment that measured shit.

Well, possibly. If some piece of equipment is very ****** I think I would be able to distinguish it from a good one.

Genuinely not trying to be controversial, but would be interested in your reply. I'm just a curious amateur don't be taking too seriously, or seriously at all which I'm sure you are not!! I have a first class honours degree in a scientific subject but not one with any relevance to hifi engineering or sound measurement...

 

[mocenigo]

Speaking about normally designed solid state amplifiers, one with THD+N of -90dB, the other with -120dB, none of them clipping with the music sample used for test, and in a properly done DBT - no one will tell a difference, I am 100% sure. You know, that chase for ultra low distortion number is just a kind of a hobby only, for those who do not know it only creates another myth, another golden calf.

I think you are right here. If two amps are decent (on a suitably complete set of measurements), and they are both used with the same sources and speakers and they are both operating in what I call their "goldilocks" zone (not only clipping), then I am sure no properly controlled test would distinguish them.

 

[AudioSceptic]

Speaking about normally designed solid state amplifiers, one with THD+N of -90dB, the other with -120dB, none of them clipping with the music sample used for test, and in a properly done DBT - no one will tell a difference, I am 100% sure. You know, that chase for ultra low distortion number is just a kind of a hobby only, for those who do not know it only creates another myth, another golden calf.

I'm sure you're right, but might -90 dB even be a bit optimistic, especially for old 'uns like me? Is there any research on just how low this needs to be, depending on age, experience, etc.?

 

[Sokel]

I'm sure you're right, but might -90 dB even be a bit optimistic, especially for old 'uns like me? Is there any research on just how low this needs to be, depending on age, experience, etc.?

Probably as low as the universal old pro standard,0.1% THD+N (60dB SINAD) if noise is at check.
If we consider that listening to a CD (16-bit/44.1KHz) the best we can do is about 95dB SINAD and that is very rarely used...

 

[Rja4000]

I'm sure you're right, but might -90 dB even be a bit optimistic, especially for old 'uns like me? Is there any research on just how low this needs to be, depending on age, experience, etc.?

I think it's a matter of margin.
The lower you go, the less margin remains.

So saying 90dB is enough is true.
Saying 90dB is not really required is probably also true.

But then, why NOT to target 90dB nowadays ?
When a $85 stereo amp may do more than 85dB...

 

[Sokel]

I think it's a matter of margin.
The lower you go, the less margin remains.

So saying 90dB is enough is true.
Saying 90dB is not really required is probably also true.

But then, why NOT to target 90dB nowadays ?
When a $85 stereo amp may do more than 85dB...

That's true,and more than that.
The problem is that this race makes people throwing away perfectly nice gear at the vague promise of improved SQ.

If you buy new go to 100dB,by all means.But absolutely no reason to ditch your older 85dB SINAD gear if is working right.

 

[Rja4000]

The problem is that this race makes people throwing away perfectly nice gear at the vague promise of improved SQ.

Probably.
But wouldn't those same people throw away their gear anyway ?
Throwing away for throwing away, at least they should go for something which is proven as good enough...

I, personally, never got rid of any hardware because it measured bad.

 

[Sokel]

Probably.
But wouldn't those same people throw away their gear anyway ?
Throwing away for throwing away, at least they should go for something which is proven as good enough...

I, personally, never got rid of any hardware because it measured bad.

Neither do I.On top of that I frequently do AB's with OP amp with the funnier one against a probably 50dB SINAD pair of 6W SETs
Nothing to complain about with either of them driving +100dB sens horns.

I certainly hope that there would be a sincere need for throwing/changing something but following the DAC threads for example I'm not optimistic.

I see people changing DACs with the same features to get the latest couple of dB SINAD better one and claim improved SQ.Some have 5 of them!
I totally get it if it's a part of a measuring rig where it needs to be 10dB better than the DUT,etc.But SQ???

 

[AudioSceptic]

Probably as low as the universal old pro standard,0.1% THD+N (60dB SINAD) if noise is at check.
If we consider that listening to a CD (16-bit/44.1KHz) the best we can do is about 95dB SINAD and that is very rarely used...

Just what I was thinking! I remember Point One (0.1%) being a landmark, and even 0.01 is "only" -80 dB.

 

[AudioSceptic]

Neither do I.On top of that I frequently do AB's with OP amp with the funnier one against a probably 50dB SINAD pair of 6W SETs
Nothing to complain about with either of them driving +100dB sens horns.

I certainly hope that there would be a sincere need for throwing/changing something but following the DAC threads for example I'm not optimistic.

I see people changing DACs with the same features to get the latest couple of dB SINAD better one and claim improved SQ.Some have 5 of them!
I totally get it if it's a part of a measuring rig where it needs to be 10dB better than the DUT,etc.But SQ???

24-bit is needed to reach those SOTA SINADs, and I'm not convinced that anything better that 16-bit is needed for most of us. Archimago has done some blinded tests which I found fascinating <https://archimago.blogspot.com/2023/05/results-internet-blind-test-of-24-bit.html>.