Audiophonics HPA-S400ET Review (Stereo Amplifier)

[nemesis.ie]

Yesterday I noticed by chance that the amp emits a relatively low-level, but still audible (when putting my ear right next to the amp) high-pitched "whining" noise when switched off. When I turn the amp on, this noise stops and is replaced by a lower-frequency noise, again not very high in level. Nothing major, but I was wondering what's going on there and if there is any way to get rid of it altogether?

SMPS idle whine probably. A lot of phone chargers are really bad for that so I can't have them in the bedroom, but the Audiophonics seem to be at a very low level in this respect and I usually have them on when in the cinema room.

I also have them powering off physically when not in use via triggers so it's never an issue.

 

[LugsyTL47]

I was going to order to ON, but since they only use the UPS, I went with Buckeye amps. Previously, UPS/Fedex charged me an enormous additional fees for customs clearance on top of 13%HST.

I’m considering Buckeye NC252. What approx customs fees to ON could I expect?

 

[bobitto]

I’m considering Buckeye NC252. What approx customs fees to ON could I expect?

Dylan sends it using regular postage or UPS. So via USPS and Canada Post I paid only about $200 CAD duties as he valued the amps a bit cheaper. I’m saying “only” because I ordered 8ch 252 and 6ch 502. Good luck

 

[Axel Endriss]

because it might be helpful for others who are thinking about this amp:
I recently got Audiophonics' HPA-S400ET. It replaces Allo's Volt+ D in my chain with Allo's Piano 2.1/Kali, Linn Wakonda as preamp, and a pair of Focal Temptation. Finding #1 is that it actually sounds audibly better to me with Audiophonics' HPA-S400ET, even though the sound with the Volt+ D was really great before (would say 99.x now when it was 95 out of 100 before). Finding #2 is that a TV plugged into a different outlet in the same room creates a hum that I didn't have before. The hum is gone as soon as I unplug the cable from the TV. The amazing thing is that this is completely independent of whether I have anything connected to the amplifier input or not. I.e. even without any input signal I have a hum on the speakers as soon as the TV is connected to the cable connection. Interestingly (for me) this is only true when I set the amplifier input to RCA. On balanced it is as quiet as a mouse, as it should be.

 

[pogo]

What kind of TV is this (plasma, ...)?
Wow, are your Temptations still running in their original condition?
I replaced mine 30 years ago, but I still remember it well

 

[Audiophonics]

Here's a fresh video review from Mike audio

 

[Sokel]

because it might be helpful for others who are thinking about this amp:
I recently got Audiophonics' HPA-S400ET. It replaces Allo's Volt+ D in my chain with Allo's Piano 2.1/Kali, Linn Wakonda as preamp, and a pair of Focal Temptation. Finding #1 is that it actually sounds audibly better to me with Audiophonics' HPA-S400ET, even though the sound with the Volt+ D was really great before (would say 99.x now when it was 95 out of 100 before). Finding #2 is that a TV plugged into a different outlet in the same room creates a hum that I didn't have before. The hum is gone as soon as I unplug the cable from the TV. The amazing thing is that this is completely independent of whether I have anything connected to the amplifier input or not. I.e. even without any input signal I have a hum on the speakers as soon as the TV is connected to the cable connection. Interestingly (for me) this is only true when I set the amplifier input to RCA. On balanced it is as quiet as a mouse, as it should be.

If in europe try plug it to the outlet in the opposite way too and see if that fixes it.

 

[Axel Endriss]

What kind of TV is this (plasma, ...)?
Wow, are your Temptations still running in their original condition?
I replaced mine 30 years ago, but I still remember it well

TV is nothing special, it's a normal LCD TV from Samsung (~6 years old). Also it doesn't matter whether it's switched on or not. The hum is there when the tv is connected to the tv cable. What I don't understand is that the hum is there even there's nothing connected to the input of the amp. So somehow the ground loop at the tv "talks" via AC power grid of the house and the amo doesn't like it (?).

My Temptations received new beading on the bass speakers and tweeters 6 years ago and thus sound like the first day again. I like the speakers a lot and would probably have to dig deep into my pocket to get comparable speakers today. I have compared them to other speakers several times over the years, but always gave my old ones the edge.

 

[Caliban]

TV is nothing special, it's a normal LCD TV from Samsung (~6 years old). Also it doesn't matter whether it's switched on or not. The hum is there when the tv is connected to the tv cable. What I don't understand is that the hum is there even there's nothing connected to the input of the amp. So somehow the ground loop at the tv "talks" via AC power grid of the house and the amo doesn't like it (?).

My Temptations received new beading on the bass speakers and tweeters 6 years ago and thus sound like the first day again. I like the speakers a lot and would probably have to dig deep into my pocket to get comparable speakers today. I have compared them to other speakers several times over the years, but always gave my old ones the edge.

You need something like this :

Cable antenna ground isolator | MadBoy Premium Karaoke Systems | Webshop

Erottaa television maan antenniverkon maasta. Ilman maaerotinta antennin ja karaokelaitteiden maiden potentiaalierot voivat aiheuttaa kaiuttimiin hurinaa.

www.madboy-audio.com

 

[Axel Endriss]

You need something like this :

Cable antenna ground isolator | MadBoy Premium Karaoke Systems | Webshop

Erottaa television maan antenniverkon maasta. Ilman maaerotinta antennin ja karaokelaitteiden maiden potentiaalierot voivat aiheuttaa kaiuttimiin hurinaa.

www.madboy-audio.com

Thx Caliban, this is a good hint!

 

[Axel Endriss]

Another question related to the HPA-S400ET: Have you tried the different gain settings and could you hear a difference?

 

[tmtomh]

Another question related to the HPA-S400ET: Have you tried the different gain settings and could you hear a difference?

I've tried medium and high gain. Zero difference (except the gain level of course!)

 

[nemesis.ie]

As mentioned previously, bypass got rid of my tweeter hiss.

 

[Snoopy]

Just saw audiophonics has integrated amps now. Ncore + ESS9038Q2.

What's the opinion on this ?

AUDIOPHONICS DAW-S250NC Class D Integrated Amplifier NCore NC252MP DAC ES9038Q2M WiFi Bluetooth 2x250W 4 Ohm 32bit 768kHz DSD - Audiophonics

Versatile and powerful, we offer you with the DAW-S250NC a real integrated and connected amplifier to which you can add speakers to enjoy your music in the best possible way...

www.audiophonics.fr

 

[Bleib]

Just saw audiophonics has integrated amps now. Ncore + ESS9038Q2.

What's the opinion on this ?

AUDIOPHONICS DAW-S250NC Class D Integrated Amplifier NCore NC252MP DAC ES9038Q2M WiFi Bluetooth 2x250W 4 Ohm 32bit 768kHz DSD - Audiophonics

Versatile and powerful, we offer you with the DAW-S250NC a real integrated and connected amplifier to which you can add speakers to enjoy your music in the best possible way...

www.audiophonics.fr

That it would be great to see measurements

 

[nemesis.ie]

I'd be interested if it had an XLR AES input.

 

[Rolka]

Hi all, I registered to this fantastic forum, because I'm interested in this amp, but after reading a lot about this one and other Eigentakt amps like the NAD 298, I'm super confused by a few things. And i worry a bit regarding sound aesthetics or what some people perceive as such, compared to a clinical sound and what change I could expect from making the switch. I have a 30 year old NAD 208 amp which is driving custom built Dynaudio 2-way speakers at 2 ohm (about 750W per channel). Back in the days I tried many amps and I honestly have no idea how much the speakers actually need to become dynamic and a joy to listen to, but back then this amp was my fav. And though I'm an electronic musician and sound designer, I've never wanted to actually exchange this compo for active speakers, because I like to listen to the sound much more than the clinical sounding monitor speakers I got to know over years, except for some very expensive ones.
When I read that these Eigentakt amps sound "neutral", I get a bit concerned that I might get listening exhaustion quickly due to absence of some "good" distortion that my NAD produces and also transients that might become too harsh in some cases?
I don't know if these concerns are justified, but related to them and the negation in this forum that changing the op-amps has a positive effect on the sound, I'm wondering if that is also true from an aesthetic perspective? And is their main purpose the coloration of the sound at all or more of a correctional stage, but due to the clean signal it's neglect able? Is it something that you'd say is so minimal that I shouldn't get concerned or is there some truth to changing them and also others things like binding posts etc? I'll quote from one customer of the discussed amp who wrote a review on the audiophonics page:

Toshiki K.
Rather good, but needs modification
The positive binding post of R Ch is unfavorably connected to GND due to the phase inversion at R Ch for reducing bus pumping. This is because negative output of 1ET400A is connected to GND internally.
Sound quality is not good enough for me, though is better than that of Hypex NC400 with SMPS600N400. I replaced the interface card with Purifi FE02 front-end board, in which OPA1612AID OPamps and low noise discrete regulators are incorporated. They seem to have higher performance than LM4562NA OPamps and conventional 3-terminal 7815 and 7915 regulators used in the interface card. I also changed cables connecting output Faston-tabs and binding posts to Cardas CROSSLINK 1S speaker cables that have star-quad configuration. The sound quality has come to be worth 5 stars.
I hear that FE02 is not permitted to be incorporated in commercial products by Purifi. Sound quality would be better if discrete 3-terminal regulators were used instead of the IC regulators in the interface card, because some sound degradation probably originates from noise and inadequate transient response of the regulators. The reason for reduction of 2 stars here is that modification is necessary for excellent sound.
Apart from the product, I felt kindness and faithfulness in customer service personnel.

What do you think about such modifications? Are they worth it, i.e. have you personally ever heard that such upgrades make a big difference in the sound? Does it come from added harmonics or a change in transients/dynamics? And would you say these differences are an increase in sound quality or rather a matter of taste?

 

[Cadguy]

Yesterday I noticed by chance that the amp emits a relatively low-level, but still audible (when putting my ear right next to the amp) high-pitched "whining" noise when switched off. When I turn the amp on, this noise stops and is replaced by a lower-frequency noise, again not very high in level. Nothing major, but I was wondering what's going on there and if there is any way to get rid of it altogether?

May I ask how close to the amp your ears have to be to hear the whine? Can you hear it when your ears are 2 feet away?

 

[AlexDD]

Is it possible to use this amp for a 2.1 system?

 

[nemesis.ie]

@AlexDD As long as your source can output a separate sub connection or your sub has high-level inputs/outputs, yes.