Audiophonics HPA-S400ET Class D Purifi amp

[TabCam]

I do not use any filtering for the AudioPhonics HPA-S400ET. No hiss at all with much more sensitive speakers while I have hiss (ear to tweeter) with my Anthem I225 / Usher Mini Dancer 2 mkII set.

Okey. I thought about buying this https://www.audiophonics.fr/en/powe...v-230v-slave-power-supply-device-p-10661.html but the dac doesn’t have trigger so it becomes useless.

thanks for the info tho

That is a nice idea. Should be enough as the Hypex SMPS1200A400 specifies 1500W max consumption. Hope the rush In current poses no problem. Here In The Netherlands we have about the same energy prices so it will earn itself back within a year I reckon.

 

[TabCam]

Ordered the https://www.audiophonics.fr/en/powe...v-230v-slave-power-supply-device-p-10661.html and it works properly. With my Anthem I could always circumvent the 12V trigger with the power button but this is much better than leaving it on 24/7.

 

[Morla]

I'm a bit sad that the first thing that happened to my audiophonics HPA-S400ET was an ugly scratch that I inflicted by the knife I used to open the delivery box.

Anybody else thinking the surface of the case is very easily scratched?

 

[carlob]

The Nord Three is pretty much the same price and better looking

 

[Morla]

To me the Nord Three looks a cheap Mediacenter PC case but I have only seen the picture on their webpage.

 

[carlob]

To me the Nord Three looks a cheap Mediacenter PC case but I have only seen the picture on their webpage.

I have the Ncore version and the case is beautiful

 

[Morla]

@TabCam: I noticed a crickling noise when set to xlr and a hum when set to rca. But only on the right channel. I changed sides to make sure it is not the speakers. Also removed power of everything but the amplifier. Since you posted a picture of your modules I could spot a difference: yours look identical while my right module look different. The little copper parts got a different color and are turned in the opposite angle. Do you think that's normal? Maybe it's time for me to open a ticket.

P.S. actually the EVAL1 pictures on the purifi-audio website are having the same difference. Maybe that's there for a good reason?

 

[Morla]

Actually it seems that noise disappears as soon as I connect a source. As if it has to load itself up first or something. Is that possible? I have only little technical experience. Odd it's only one channel.

 

[JimB]

Actually it seems that noise disappears as soon as I connect a source. As if it has to load itself up first or something. Is that possible? I have only little technical experience. Odd it's only one channel.

For many systems, it's normal to have relatively high noise with an open input. What matters is the noise with your source connected.

 

[mocenigo]

The Nord Three is pretty much the same price and better looking

I happen to disagree.

 

[TabCam]

@Morla If you do not connect anything, even short wires can act as antenna and pick up noise.

I had a fun audio evening comparing the HPA-S400ET to a Unison Research S9 tube amplifier driving two Focal Sopra 1's. They were in a sense very close. Both were very natural and open sounding on the Sopra 1's.The bass was much tighter and more defined on the Purifi, the midrange a win for the S9 and a draw for the highs.

There was a hiccup at the start. The S9 was connected to a netfilter. As soon as we swapped in the Purifi it did not sound natural at all. Fortunately I brought an el cheapo power cable and as soon as as we connected it directly to the power, everything was more than fine!

 

[boggit10]

I guess carlob has the SE case.

 

[March Audio]

@TabCam: I noticed a crickling noise when set to xlr and a hum when set to rca. But only on the right channel. I changed sides to make sure it is not the speakers. Also removed power of everything but the amplifier. Since you posted a picture of your modules I could spot a difference: yours look identical while my right module look different. The little copper parts got a different color and are turned in the opposite angle. Do you think that's normal? Maybe it's time for me to open a ticket.

P.S. actually the EVAL1 pictures on the purifi-audio website are having the same difference. Maybe that's there for a good reason?

Those inductors won't be the cause of any hum you are hearing. Probably just a different batch or supplier.

Probably ground loop, pin 1 problem.

 

[carlob]

I guess carlob has the SE case.

I do as you probably know. Very satisfied with that amp btw.

 

[Morla]

Those inductors won't be the cause of any hum you are hearing. Probably just a different batch or supplier.

Probably ground loop, pin 1 problem.

Do you have an idea on where to look for this issue? I have attached a picture. To me left and right looks identical?

 

[Morla]

@Moria; If you do not connect anything, even short wires can act as antenna and pick up noise.

I would have thought this would happen to both channels but yes.

I use speakers with high sensitivity (measured 96dB by stereophile). Maybe that is a part playing a role in this?

 

[boggit10]

I would have thought this would happen to both channels but yes.

I use speakers with high sensitivity (measured 96dB by stereophile). Maybe that is a part playing a role in this?

I would try and cut that cable tie holding the right channel input to the loosely twisted speaker output wire., might just help and easy to achieve.
Edit (had not noticed the left was the same, but worth a try still)

 

[Audiophonics]

Hello, we tried to detect this behavior
Yes, if no source is connected AND the RCA input selected, we can hear a noise on the right channel.

This is because the switch connect negative input with ground, and cancel the balanced design that remove any perturbation.
We found that this perturbation comes from SMPS1200 main capacitors.

One easy solution can be to route the right input wire under the IEC connector, along the back panel.

But this problem only occur when there is no source, because wires are on air and act as antenna with 47k impedance.
When a source is connected, no sound can be heard.

However, from today, we will take this parameter into account for our next assemblies.

 

[TabCam]

I would have thought this would happen to both channels but yes.

I use speakers with high sensitivity (measured 96dB by stereophile). Maybe that is a part playing a role in this?

Efficient speakers will probably excarbate the problem but I have a hiss with my Anthem I225 and it is only detectable from short range (ear close to tweeter) with both an efficient and normally efficient speaker.

 

[tmtomh]

Possibly dumb question: Does the HPA Purifi amp use only one power supply for cost reasons, or because the Purifi modules (unlike, say, the Hypex 400 modules) don't run into current problems with only one PSU driving both channels?