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Audiophonics HPA-S400ET Review (Stereo Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 0 0.0%
  • 2. Not terrible (postman panther)

    Votes: 3 0.8%
  • 3. Fine (happy panther)

    Votes: 29 7.5%
  • 4. Great (golfing panther)

    Votes: 353 91.7%

  • Total voters
    385

Chester

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A lot of the tests were shown with the op-amps and buffers totally bypassed, which strikes me as unhelpful - they're going to be one of the main potential sources of difference between Purifi implementations, and most people will be using them, so for the tests to be useful for comparisons, you want to keep them in-circuit throughout. Otherwise you're just re-testing the bare Purifi modules, almost. (But I guess you learn a bit about the wiring.)
I think Amir has tested a range of Purifi based amps now, some with better (on paper) op-amps and there was no real difference.
 

Mehdiem

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Loathecliff

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View attachment 194307

If you're in Europe, this is a "no-brainer" purchase, if you want the best Class D performance, for a cost.
Otherwise, Hypex nCore amps are the cheaper alternatives.
Nah. Am in Europe, but I think I'll buy a Behringer A800 & spend the change on adding to the wine cellar.
I agree, I'm beyond help.
 

amper42

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I hear a subtle pop with my C298 every time I turn it on. I contacted NAD and they said this:

"Regarding about your C298.

I have asked our engineers and they comment that is normal. The chassis would make a click when the PSU turns on. And if the speakers are sensitive, they would make a faint pop/crack upon turning on."

Amp models vary quite a bit on whether they make a pop on startup. Here are some examples from amps I own:
1. March Audio P452 - Purifi based amp makes a whisper quiet crackle noise in the speaker when turned on. It's not an issue, it basically tells me it's started up. My guess is you can hear a small crackle in most Purifi builds with a OPA1612 op amp and no MCU to control crackle/pop output.
2. Buckeye Late 2021 NC502MP - amp makes ZERO noise when turned on. The only way I know it's on is the power light.
3. Monolith 7x200 - dead quiet. Makes zero noise in the speaker on startup.
4. Soundcraftsmen S800 - big to medium pop in speaker on startup. Fan noise as well. :cool:
4. Adcom GFA-7000 - amp makes a thunk noise when turned on and registers a 330W power surge on Kill-a-watt at turn on. If I turn it on after the Denon 4700 it will power surge the 4700 into a restart and any music that might have been playing will stop. I have learned if the Adcom will be in use I need to turn it on first and then everything else. :D

In my experience, recently built amps are typically far better at controlling speaker pop/crackle on power up than those made 10-20 years ago.
 

C. Cook

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I like the heat sinking approach for the SMPS module. However, I can't see any mechanical/thermal connection to the heat sink near the Purifi amp modules. I suppose they're mounted directly to the bottom of the chassis and the bottom of the chassis connects directly to the heat sink, but I can't be sure or if it's so; how.

I was wondering if anyone could weigh in on how hot this thing runs both during audio playback and idle.
 

ivo.f.doma

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Hi. I want to ask the experts whether the power supply that is mounted in this amplifier would be enough for a 3-channel version. Audiophonics offers this 3x Purifi variant and I'm interested in it, I'm just worried about the sufficiency of the power supply.
 

Vincentponcet

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Hi. I want to ask the experts whether the power supply that is mounted in this amplifier would be enough for a 3-channel version. Audiophonics offers this 3x Purifi variant and I'm interested in it, I'm just worried about the sufficiency of the power supply.
I was thinking the same to complement a Denon x3700h to power LCR, when I will add 4 Atmos later this year.
When I see the power consumption of my Denon being at less than 100watts of consumption with 5 loud speakers according to its power indicator, I don't think I will need 3*200watts continuously just for LCR, and in worse case, I will loose 33% of power, so less than a db.
So it sounds like being a limiting factor, but practically not in the usable range I would say.
 

peng

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I was thinking the same to complement a Denon x3700h to power LCR, when I will add 4 Atmos later this year.
When I see the power consumption of my Denon being at less than 100watts of consumption with 5 loud speakers according to its power indicator, I don't think I will need 3*200watts continuously just for LCR, and in worse case, I will loose 33% of power, so less than a db.
So it sounds like being a limiting factor, but practically not in the usable range I would say.

Great point, I guest most people don't realize their amps are outputting less than 1 W per channel on average when watching a movie at well below reference level. It could be much higher during peaks obviously, but even then it would not likely exceed their amps rated "continuous" output. Some people also claimed they got much better sound regardless, such as hearing things they never heard before, and even at low volume, after adding an external amp. Yet some of those amps have worse specs and measurements (such as higher THD+N) than their AVR amps. So we can tell people its good to have more power than they need, and it is good to use external amps but don't expect sound quality to sound noticeable different. A few may listen, but more would likely go ahead, and many will hear things regardless, with help from their eyes and mind...

What do you mean by "according to its power indicator?:)
 

amper42

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I was thinking the same to complement a Denon x3700h to power LCR, when I will add 4 Atmos later this year.
When I see the power consumption of my Denon being at less than 100watts of consumption with 5 loud speakers according to its power indicator, I don't think I will need 3*200watts continuously just for LCR, and in worse case, I will loose 33% of power, so less than a db.
So it sounds like being a limiting factor, but practically not in the usable range I would say.
Not sure how you are measuring Denon 3700 energy use. My Denon 4700 measures 132W in idle with Kill-o-watt. Obviously, watts used will be increased at 85dB. I don't think it's possible for the Denon 3700 to measure 100W while in use. Except, if you use it in full pre-out mode with no internal amps powering speakers. It's power use should drop to 46W no matter what the volume level is set at in full pre-out mode.
 
Last edited:

Blimcheck

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I don’t understand the price of the review, only 490 euro? And what you mean member of this group? There is a special price for the members of this grou?
 

ririt

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I don’t understand the price of the review, only 490 euro? And what you mean member of this group? There is a special price for the members of this grou?
The price is 1490€ not 490€. Unfortunately being a member of ASR does not provide any advantage!
 

Vincentponcet

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What do you mean by "according to its power indicator?
Ahahh I probably misread the bar under eco indicator on the screen. This amp is new to me.

Not sure how you are measuring Denon 3700 energy use. My Denon 4700 measures 132W in idle with Kill-o-watt. Obviously, watts used will be increased at 85dB. I don't think it's possible for the Denon 3700 to measure 100W while in use. Except, if you use it in full pre-out mode with no internal amps powering speakers. It's power use should drop to 46W no matter what the volume level is set at in full pre-out mode.
My bad.
What the power indicator on the OSD is providing?
I see roughly 50-60% of the bar.
Anyway, this is far below the 1200w of the audiophonics 3 channels purifi.
As I understand the 3700 has a power supply of 550watts, isn't?
 

peng

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Ahahh I probably misread the bar under eco indicator on the screen. This amp is new to me.


My bad.
What the power indicator on the OSD is providing?
I see roughly 50-60% of the bar.
Anyway, this is far below the 1200w of the audiophonics 3 channels purifi.
As I understand the 3700 has a power supply of 550watts, isn't?

Not really, manufacturers rarely tell you the power supply VA rating. Denon does specify the power consumption, in this case it is 660 W for the AVR-X3700H, but they don't specify the conditions so that 660 W is not a very useful indicator. For example, Yamaha typically specify two power consumption figures, one being "maximum".

In my opinion, the only thing you can assume is, a Denon AVR (or Marantz) that has a higher power consumption figure will mostly likely have a power supply larger than a Denon/Marantz AVR (assuming same year model) that has a lower power consumption figure, but you cannot compare such figures with another brand, such as Yamaha, using the same basis even if both use class AB design for their power amps.
 

Bleib

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Would this poweramp work with Topping EX5 used as a pre-amp?
 

amarsicola

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I received the small case version (LPA-S400ET ) about a month ago. Very good the experience with Audiophonics (they helped me with some explanation on input gain configurations). My thoughts:

Cons (minimal):
1. Some design choices: the power switch is bi-stable, meaning if the general circuit breaker of home shuts down and then restarts, the amplifier is also restarting again. I would have preferred a mono-stable circuit breaker since safer. And maybe the cooling vents are too wide.
2. The configuration I received is the one with maximum gain (~ 2.25V RMS), and this is absolutely reasonable since all the jumpers are connected in this configuration. Audiophonics website says the default configuration should be the medium gain one ( ~ 4.2V RMS), the one i wanted, but this configuration would require the "Gain+" jumpers to be disconnected. So i had to open the amplifier by removing the top cover (just pull 2 screws at the front and 2 at the back). It is not a real defect, just a warning in case you cannot resist to plug-in your new amp and you have a high-voltage source: check the volume is not high to avoid clipping. Shit happens. I just wrote them an email asking to update their product page with the correct default configuration.

Pros:
1. Build quality: when i opened the amplifier to remove the jumpers, i noted the build quality and the engineering are very accurate from this detail: the bottom side of the case had a sort of rails on the edges, so that the top cover fits perfectly. Wow. The case is quite thick, the gold-plated speaker terminals are chunky as they would be in a snake-oil million dollar amp. The interior is crowded but well in order.
2. Blue leds you can see from the cooling vents are fancy
3. OMG the sound is unbelievable. I have a pair of Revel F208 and the source is a Topping D70S. As the amplifier was switched on (with just a barely noticeable hump) I noticed a very slight hiss from the Revel's tweeter. Then i switched on the source, and the hiss disappeared. The loudspeaker was completely silent like no other amplifier before (I had a Nad C320BEE and a Nuprime ST-10).
Then the music started, i noticed much more details were coming out of the speaker than usual. Soundstage was very focused, and bass was very well defined, the woofers being fully under control of the amplifier. I didn't do any blind test, just have a subjective feeling that this is by far the best amplifier i had.
After some hours playing, the case is mildly warm, less than the Nad or the Nuprime. Very good.
 

ivo.f.doma

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I received the small case version (LPA-S400ET ) about a month ago. Very good the experience with Audiophonics (they helped me with some explanation on input gain configurations). My thoughts:

Cons (minimal):
1. Some design choices: the power switch is bi-stable, meaning if the general circuit breaker of home shuts down and then restarts, the amplifier is also restarting again. I would have preferred a mono-stable circuit breaker since safer. And maybe the cooling vents are too wide.
2. The configuration I received is the one with maximum gain (~ 2.25V RMS), and this is absolutely reasonable since all the jumpers are connected in this configuration. Audiophonics website says the default configuration should be the medium gain one ( ~ 4.2V RMS), the one i wanted, but this configuration would require the "Gain+" jumpers to be disconnected. So i had to open the amplifier by removing the top cover (just pull 2 screws at the front and 2 at the back). It is not a real defect, just a warning in case you cannot resist to plug-in your new amp and you have a high-voltage source: check the volume is not high to avoid clipping. Shit happens. I just wrote them an email asking to update their product page with the correct default configuration.

Pros:
1. Build quality: when i opened the amplifier to remove the jumpers, i noted the build quality and the engineering are very accurate from this detail: the bottom side of the case had a sort of rails on the edges, so that the top cover fits perfectly. Wow. The case is quite thick, the gold-plated speaker terminals are chunky as they would be in a snake-oil million dollar amp. The interior is crowded but well in order.
2. Blue leds you can see from the cooling vents are fancy
3. OMG the sound is unbelievable. I have a pair of Revel F208 and the source is a Topping D70S. As the amplifier was switched on (with just a barely noticeable hump) I noticed a very slight hiss from the Revel's tweeter. Then i switched on the source, and the hiss disappeared. The loudspeaker was completely silent like no other amplifier before (I had a Nad C320BEE and a Nuprime ST-10).
Then the music started, i noticed much more details were coming out of the speaker than usual. Soundstage was very focused, and bass was very well defined, the woofers being fully under control of the amplifier. I didn't do any blind test, just have a subjective feeling that this is by far the best amplifier i had.
After some hours playing, the case is mildly warm, less than the Nad or the Nuprime. Very good.
Does the AUDIOPHONICS LPA-S400ET contain a 5-12V trigger?
 
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