Audiophonics HPA-S400ET Review (Stereo Amplifier)

[dlt123me]

Hi all!

This is my VR-03B balanced amp that I made in 2021 based on a Purifi 1ET400A.
The power supply made by the classical way, using transformers,
the toroidal transformer was made specifically for this project.

It sounds extremely realistic and clear nboth at minimum volume and at maximum.
You can listen to any musical genres indefinitely. The amplifier sounds musical and very informative.
I've owned many different amps and can say that what Purifi does in Class D these days is the highest sound quality.

I wish I could do something like this. I do not have any electrical engineering skills. Looks very well put together. Are you starting an amp business??? Nicely done.

 

[geekosa]

Do we know the measured damping factor of this amp ?

 

[EdW]

Do we know the measured damping factor of this amp ?

If you go to the Purifi website you can view the data sheet for thr 1ET400 module. It shows an output impedance varying from 50 micro ohms to approx 600 micro ohms at the top of the audio band. So comparing 8 ohms (nominal speaker). to 600 micro ohms we see a damping factor of ~1333
EDIT: my mistake 8 ohm/600u = 13,333 times! This is worst case and probably the low frequency figure of O/P impedance of 50u is more relevant for loudspeaker woofer control. Bear in mind that 10AWG copper speaker cable is ~2milli ohm per foot. So in any practical situation the speaker wires will dominate the damping factor . .

 

[geekosa]

If you go to the Purifi website you can view the data sheet for thr 1ET400 module. It shows an output impedance varying from 50 micro ohms to approx 600 micro ohms at the top of the audio band. So comparing 8 ohms (nominal speaker). to 600 micro ohms we see a damping factor of ~1333

That's huge !

 

[Mcsadapted]

I contacted Audiophonics but didn’t get a definitive answer. My question was if the output of a current Bluesound Node is sufficient to drive amp in discussion here to drive the amp under discussion here. If anyone has paired these two units I would greatLu appreciate hearing about it.

 

[mike70]

The specifications says:

With 20dB gain the sensitivity is 4.2V
With 25.3dB gain (default) the sensitivity is 2.2V

If the Bluesound have 2V in the output ... you can drive the amp to the max power.

This information says the output is 2.1V ... so everything's ok.

https://support1.bluesound.com/hc/e...nect-Node-2-to-Harman-Kardon-power-amplifier-

 

[Mcsadapted]

The specifications says:

With 20dB gain the sensitivity is 4.2V
With 25.3dB gain (default) the sensitivity is 2.2V

If the Bluesound have 2V in the output ... you can drive the amp to the max power.

This information says the output is 2.1V ... so everything's ok.

https://support1.bluesound.com/hc/e...nect-Node-2-to-Harman-Kardon-power-amplifier-

Thanks so much…. I will be placing my order with Audiophonics today. I’m currently using the 80 watt Powernode version from Bluesound with a pair of Focal towers (1038 Be) and that seems like a bit of a mismatch.

 

[hansik]

Got mine last week. Playing at concert level in my 18x15' room on my 105db sensitive JBL 4722's, the amp remains completely cold.

 

[restorer-john]

This piece isn’t perfectly parallel to the case so this amp gets a headless panther vote from me.

/sarcasm

View attachment 194304

You actually (unknowingly) made a good point back then.

That board is the switched/trigger board for the live mains power input and it is held in-situ by the round nuts on the 3.5mm trigger sockets. That is a poor and potentially dangerous way of securing that board IMO. Those sockets are not meant to hold anything but themselves, not a PCB with a few relays and cable under tension.

I would expect that in time, they will crack, and the board could float around, potentially with the uninsulated solder joints contacting the chassis.

 

[TheWalkman]

You actually (unknowingly) made a good point back then.

That board is the switched/trigger board for the live mains power input and it is held in-situ by the round nuts on the 3.5mm trigger sockets. That is a poor and potentially dangerous way of securing that board IMO. Those sockets are not meant to hold anything but themselves, not a PCB with a few relays and cable under tension.

I would expect that in time, they will crack, and the board could float around, potentially with the uninsulated solder joints contacting the chassis.

Restore-John,

As someone who has likely opened more amps in a typical month than I’ll open in my lifetime, I’ll defer to your conclusion that the trigger board might be better designed.

As the owner of this amp for going on a year, I’ve plugged a trigger cable into the amp exactly once and have never unplugged it from my Topping DAC.

Perhaps our friends at Audiophonics will see this comment and improve the design of the trigger board for the next Rev of the amp but to be honest, I won’t be losing any sleep over this possible oversight.

 

[Audiophonics]

The trigger board was originally designed with an attachment point on the IEC screw, but the assembly was not convenient and we found that it was already securely attached with jack sockets.
We have no cases of a broken socket or an issue with attaching this board, but we will think how to improve that.

 

[AudioSceptic]

You actually (unknowingly) made a good point back then.

That board is the switched/trigger board for the live mains power input and it is held in-situ by the round nuts on the 3.5mm trigger sockets. That is a poor and potentially dangerous way of securing that board IMO. Those sockets are not meant to hold anything but themselves, not a PCB with a few relays and cable under tension.

I would expect that in time, they will crack, and the board could float around, potentially with the uninsulated solder joints contacting the chassis.

That's a good point, but what is likely to cause any crack? How often will there be stress applied there? Won't it just be to the sockets themselves anyway, which are well secured to the case?

 

[Rja4000]

After circling around for quite some time, I finally purchased one.

This is really a top-class looking amplifier !

 

[ommadusk]

Hi. I've ordered a Nilai500DIY mono kit x2 for my system, which has 2x Polk R200 86dB speakers and I'm positioned 3-4 meters away from the speakers. Have I made a mistake? If so I can cancel or return the order. Do you think this amp would be a slightly better choice? I'm thinking it has slightly better specs and a stereo amp would be neater.

 

[Joel G]

Side story, I have a pair of home built and assembled speakers whose kit I ordered because I believed in the specs and were within my budget and I wanted the diy challenge. It took me long to finish them but now they are to me the element in my system which i’m happiest with, probably because of the personal effort involved. And I think they sound really good of course.

Maybe it is more down to wether you want to have a done by yourself or a bought by yourself amp since they are both greatly rated amps made by almost sister companies? Just my two cents.

That said, my HPA-S400ET is very close to my speakers as the element I am least likely to change in my system

 

[ommadusk]

@Joel G thank you I decided to get this stereo amp and cancel/return the other order. I was concerned this one might not have enough power for my speakers but I think it's got plenty for how I use it and I'd prefer not to have to assemble an amp.

 

[BR52]

@Joel G thank you I decided to get this stereo amp and cancel/return the other order. I was concerned this one might not have enough power for my speakers but I think it's got plenty for how I use it and I'd prefer not to have to assemble an amp.

It's a good decision, I guess. With my Audiophonics Purify I'm really satisfied.

 

[Timsonchin]

I have this smaller form:

AUDIOPHONICS LPA-S400ET Class D Stereo Amplifier Purifi 2x400W 4 Ohm​

excellent piece of equipment and great service from audiophonics france! I wanted the op-amps replaced with Sparkos. They did it at a good price and sent to the Netherlands without problems.

they are very easy to reach by phone and speak good English.

fast Shipment too.

I'm looking to add auto-on using a master-slave socket: when my miniDSP is powered on, it will provide power to the LPA-S400ET. But I'm not sure if the button in the front will allow that to work.

How does the button on the front of the unit work? Do you have to press it every time the amp has been turned off and on again?

 

[BR52]

I'm looking to add auto-on using a master-slave socket: when my miniDSP is powered on, it will provide power to the LPA-S400ET. But I'm not sure if the button in the front will allow that to work.

How does the button on the front of the unit work? Do you have to press it every time the amp has been turned off and on again?

Not with my amp. I do it with my amp via a remote control power outlet for streamer , power amp and E70 DAC

 

[Rja4000]

After circling around for quite some time, I finally purchased one.

This is really a top-class looking amplifier !

OK
So adding some subjective feedback now:
This amp just works.
It drives with authority any speaker I connected to it.
A pair of Focal 948, an old pair of Cabasse Skiff (1994 edition), an even older pair of B&W DM14....

In any case, one thing is clear:
The performance bottleneck is not the amp.

Add this magic RME ADI-2 (and its EQ) and any speaker just gives its best.

Good.
That's exactly for that purpose that I bought it.