Audiophonics HPA-S400ET Review (Stereo Amplifier)

[Grael]

I wonder why the Audiophonics amplifier did not mount one of the two modules on the other side, making some use of the unused heatsink. The two heatsinks could then both be made smaller and both would then be gainfully employed. The supply module could sit in the middle, between the two amplifier ones.

If you really want symmetry, you can get 2 mono blocks for the same price.

AUDIOPHONICS AP300-M400ET Power Amplifier Purifi 1ET400A

The Audiophonics AP300 is a class-D mono power amplifier based on a PURIFI 1ET400A module and a HYPEX SMPS600A400 power supply, capable of delivering 400W @ 4 ohm.

www.audiophonics.fr

But as @Bob101 said, the power supply is what generates the most heat (not much...)

 

[wyup]

What do you think of using a linear power supply to feed the input buffer board instead of using the SMPS1200A400 15.6Vdr aux?
Apollon audio does this to their premium Purifi and NCore amplifiers like this:

It makes sense because a LPS is more suited to power the sensitive line-signal to the opamps, instead of a SMPS, as many dacs do.
It uses an encapsulated toroidal transformer from the mains and a circuit board with regulators, just as the Audiophonics input buffer does.

There is some space available inside the box by the middle, I wonder if you could fit one of their all-in-one LPS boards like these:

Linear Power supply Module regulated DC +/- LM317T / LM337 1.25V / 18V 0.5A - Audiophonics

Le module d'alimentation linéaire DC régulé LT1083 a été conçu pour alimenter proprement un Amplificateur ou autre circuit audio en continu.

www.audiophonics.fr

Regulated DC Power Suppy Module LM317 / LM337 - Audiophonics

This 25W regulated linear power supply module offers a quality design based on proven components. A large 25VA transformer, ELNA and WIMA capacitors, LM317 and LM337 voltage regulator are used to provide a clean and stable electrical signal.

www.audiophonics.fr

You only need to adjust +-15.6 Vdr to the LPS output to match the SMPS1200A400 Vaux ribbon connector, enough for 500mA.

I mean, Apollon audio sells 4.5k€ for their dual mono 1ET7040SA Purifi amp with this LPS for line-stage and two Hypex SMPS1200A400 for the Purifi modules.

 

[cicastol]

What do you think of using a linear power supply to feed the input buffer board instead of using the SMPS1200A400 15.6Vdr aux?

Pretty useless??

 

[mike70]

Pretty useless??

In other way ... Why Hypex since the beginning recommends a switching power supply?

 

[ComasSky]

Hi !

Do you have pops when switching on and off ? And if so, do you have any solutions ?
My speakers are on high output, so the noise is quite noticeable (but not very loud either).

 

[staticV3]

Hi !

Do you have pops when switching on and off ? And if so, do you have any solutions ?
My speakers are on high output, so the noise is quite noticeable (but not very loud either).

Here's a possible solution: https://neurochrome.com/products/guardian-86

 

[ComasSky]

Thanks !

I dont know if i want spend 24O$ only to remove pop ...

 

[wyup]

In other way ... Why Hypex since the beginning recommends a switching power supply?

Because the input buffer/preamp circuit power supply quality is more important/sensitive to noise than that of the power module itself.

As a proof and for the same reason, Neurochrome offers a preamp power supply for both Purifi and Hypex input buffers:

Preamp Power Supply

The Preamp Power Supply powers preamplifiers, headphone amps, phono stages, and buffers. It provides ±12V at up to 650mA with an ultra-low noise floor for the best sound quality.

neurochrome.com

Ideally I guess it would be optimal to feed the power modules with a toroidal transformer based linear power supply, but these are large and bulky and defeat the class D SMPS minimal space and efficiency approach. I have seen setups like this in diyaudio.com.

I only respond to your question and show an approach. Feel free to disregard.

 

[mike70]

Feel free to disregard.

i don't have the knowledge to agree / disagree ... but surely the SOTA results on hypex / purifi modules with switching power supplies tells me that toroidal transformers aren't a critical requirement in this kind of amplifier.

 

[ComasSky]

Still have some serious pop on start / shutdown of my HPA ... even without sources on XLR / RCA ..

 

[Nick_L]

Still have some serious pop on start / shutdown of my HPA ... even without sources on XLR / RCA ..

Do you start/shut down your streamer or your power amp? For me this looks like a problem with your audio source..

 

[ComasSky]

Do you start/shut down your streamer or your power amp? For me this looks like a problem with your audio source..

In this video, i shut off and power on my source (Atoll ST300, 3k€) with trigger use.
But it does the same without source (no RCA, no XLR connected).

 

[Nick_L]

Sorry to hear ComasSky,
my new LPA-S400ET is very silent when I switch it on or off.
I would contact Audiophonics again for support.

 

[AweLoi]

Do the HPA-S400ET have any type of protection circuit? The NAD M23 do have one but of course it cost a lot more.

 

[pogo]

What kind of protection circuit do you mean?

 

[Salt]

SMPS as well as Purify Amp modules do have their security protection in their own, as far as I'm informed.
What's Your request in detail?

 

[AweLoi]

SMPS as well as Purify Amp modules do have their security protection in their own, as far as I'm informed.
What's Your request in detail?

I'm not sure what type of protection circuit is common but my Classé CA-2100 have some protection circuits that have saved my speakers on a couple of occations. Amp goes into protection mode. I also know that many brands have these kind of circuits to protect your gear. Not sure what exactly they do though. But for instance to protect your speaker drivers from blowing if something goes wrong electrically. If there is some anomaly in the signal. But I don't really know how they work more than that they exist and have saved my speakers.

 

[nemesis.ie]

1ET400A Amplifier Module

purifi-audio.com

As mentioned by @Salt, you can see protection mentioned on the module spec page linked above and if you look at the pictures on the Audiophonics site, it looks like they pop in the same module and connect the SMPS via their own buffer board. I see no reason the 1ET400 module's protection would be bypassed.

If you are still concerned, maybe email or PM them?

 

[AweLoi]

1ET400A Amplifier Module

purifi-audio.com

As mentioned by @Salt, you can see protection mentioned on the module spec page linked above and if you look at the pictures on the Audiophonics site, it looks like they pop in the same module and connect the SMPS via their own buffer board. I see no reason the 1ET400 module's protection would be bypassed.

If you are still concerned, maybe email or PM them?

Good idea!

NAD M23 have a protection mode. I don't know if they have designied their own or use Purifis built in. I will email Purifi and Audiophonics.

 

[AweLoi]

1ET400A Amplifier Module

purifi-audio.com

As mentioned by @Salt, you can see protection mentioned on the module spec page linked above and if you look at the pictures on the Audiophonics site, it looks like they pop in the same module and connect the SMPS via their own buffer board. I see no reason the 1ET400 module's protection would be bypassed.

If you are still concerned, maybe email or PM them?

I looked at the data sheet in the link you provided. The Purifi module seem to have quite extensive built in protection already matching the protection my Classé provides according to the manual. All good! Thanks for the help. I think I will sell my Classé and buy this instead.