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Audiophonics HPA-S400ET Review (Stereo Amplifier)
- Thread starter amirm
- Start date
Yup, listen in RCA. XLR only when you power and amp are far apart more than 3 meters run.
Nonsense. Are you aware that DAC/Preamp balanced outputs give you twice the voltage...? Which could be, I don't know, needed for a 12 to 25dB Gain amp?
If you care to see all measurements in this site you would see balanced outputs from DACs measuring better than RCA even on short distances. Balanced signal sums and cancels distortions. It makes no sense to use RCA if you have XLR option, independent of distance.
Just for sound. I do owned another french product that product that has XLR and RCA offered. The designer say on website not to use XLR. RCA sound better on his product. Some power amp you can compensate the gain loss. Of course, you have email them.
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Very cool! So the secret sauce is in the buffer. Cant quite see what the opamp is?
Would be nice if the gain switches were on the outside so could change without needing to open up.
Would be nice if the gain switches were on the outside so could change without needing to open up.
My speakers cannot handle max power so I kept it to lowest gain (config 3 = bypass mode = 12.8dB), I remember reading somewhere that a buffer input is still recommended for these modules to ensure high input impedance... Not sure how this "bypass mode" deals with it...
Configuration of input gain is done through jumper selection:
Configurer Gain & Bypass sur module Amplificateur Purifi - Le Blog d'Audiophonics
Retrouvez le blog d'Audiophonics!www.audiophonics.fr
Sorry citing myself lol...
@amirm, your tests seem to show that there is no "input impedance" problem with the "bypass mode".
Thank you for this, I feel more confortable keeping it like that to prevent exploding my small speakers
Here is a summary of the input buffer configurations and corresponding gain (purifi module gain is 12.8dB):
Configuration 1 (Default = mid gain): +7.2dB (+12.8dB = 20dB)
Configuration 2 (Gain+ = high gain): +12.5dB (+12.8dB = 25.3dB)
Configuration 3 (Bypass = low gain): +0 (+12.8dB = 12.8dB)
@maty thanks for the screenshot, you were faster than me, sorry for duplicated information
BTW documentation is not clear on whether it is config 1 or 2 by default (depends on the page you read).
Can't remember on mine (I probably have pictures somewhere), so one should check before install and use.
Edit:
Found the picture of original configuration, it was "Configuration 2 = high gain": Jumper on "2+3" and another jumper on "Gain+".
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Funny, I was looking at the 'compact' version and some SparkoS OPamps.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!
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.
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maty
Major Contributor
[ A Texas Instrument LM4562 OPA per channel is used, these are very low distortion AOPs offering the greatest transparency with a very low THD. They are mounted on socket allowing their replacement if necessary. ]
Still nonsense all the same. What "french product" is that? If a gear is designed to sound better using RCA over XLR, then I call it incompetence. Period.
PS: Both RCA and XLR could not "sound" the same because one is usually twice as low as the other. Level-match both and you will be hard pressed to hear any difference.
Doesn't work that way. If you don't have enough output voltage, you can miss the power as well.
TI LM4562
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I suppose videos take time and some effort, but they are really great on helping people understanding what the different measurements and graphs really mean, at least for me the videos are very helpful at that.
Of course if Amir could add some cool VFX like Paul does with his videos, that would take the whole thing on the next level. Until then we'll have to do with plain facts and science, oh well...
JSmith
Master Contributor
$1,700 - damn good deal. Shows that you don't need to spend $tupid money to buy a SOTA amp with lots of power. What are the companies providing that are charging $25k and up for a power amp? Lots of them out there.
I live in France and was actually considering to buy the "same" (well... Purifi-based) amp built by VTV.
Adding shipping from US + import taxes, it was still a bit cheaper delivered to France than the Audiophonics option... I finally went for Audiophonics for easier warranty and eventual return.
For US-based people though, I'm not sure it makes sense...
You can get a VTV version for less than 1200 USD (they have their own buffer, or the 'official' Eval-1 is even cheaper).
They are supposed to be well built too, not sure whether the different input buffer would make a difference...
Adding shipping from US + import taxes, it was still a bit cheaper delivered to France than the Audiophonics option... I finally went for Audiophonics for easier warranty and eventual return.
For US-based people though, I'm not sure it makes sense...
You can get a VTV version for less than 1200 USD (they have their own buffer, or the 'official' Eval-1 is even cheaper).
They are supposed to be well built too, not sure whether the different input buffer would make a difference...
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I am surprised that even the best class D amplifiers like Purifi are unable to do better in high frequency non-linearity. This is still below just very good class AB amplifier measured at @45kHz BW. Still space for technical improvements.
Well, you can volume matched at least. A well design XLR or differential amplifier has darker back ground. It's really show in the noise level. Subjectively RCA is more simple in design and more lively. It is just harder to suppress the noise. XLR also has a flaw in real world, the signal don't get to sum perfectly to get rid of noise and alter original signal. In real world, no one hand down one another. It is up to designer skill. I would really ask them about which connection is better. Brand like Mark and Krell are by default sound best in XLR pre/power. It is like some manufacturers are hardcore Class A amp than Class AB amps.
Voltage drop shouldn't be a concern, just ask. If RCA better for subjective good sound, it does save you money. For me, I just use over spec cable.
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Nice review !
To put this in context - a passive driven loudspeaker with this power amp will not sound as good as a very good active system with active dsp crossover and less good poweramps for each driveunit .
The passive crossovers in most loudspeakers are still the BIG bottleneck.
So you can possible have a better result making a good passive loudspeaker active using a good dsp crossover, and buy cheaper amps from audiophonics, for the same money.
To put this in context - a passive driven loudspeaker with this power amp will not sound as good as a very good active system with active dsp crossover and less good poweramps for each driveunit .
The passive crossovers in most loudspeakers are still the BIG bottleneck.
So you can possible have a better result making a good passive loudspeaker active using a good dsp crossover, and buy cheaper amps from audiophonics, for the same money.
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