AUDIOPHONICS MPA-S250NC Amp Review

[soerenssen]

4R bridged is not spezified and 2R use activeted the protection circuit. So it will have at least 500W bridged, maybe more shortterm. The KEF is spezified 15-250W.
It seems a stretch for the amp and the speaker.

Thank you for your help!

 

[Acerun]

@Acerun SPL levels in rooms don't fall off at 6dB per double distance! (I bet the Crown app is calculating with that)
You are sitting in the pure reverberant field in a normal room in 3m - you will get higher SPL.

Thank you for the comment. Sounds like this should be plenty enough amp for my needs. What is the ideal amount of headroom in your opinion?

 

[Dave Bullet]

Power handling is an interesting question. There are 2 maximums for a conventional voice coil driver. Thermally limited and mechanically limited. Here is the max SPL graph for an SB Acoustics 12" woofer. In most speaker systems it is the bass drivers that ultimately limit max SPL, as it takes 4 times the excursion (cone travel) with every halving of frequency to maintain the same SPL. This bottom attached curve is "free air" - that is no enclosure assisted power handling. What this shows is the maximum free air SPL this woofer will produce (when it runs out of cone travel) is approx 95dB at 25Hz. 20watts at 100Hz however can be played at 105dB

Now interestingly the power required to reach maximum possible excursion (and SPL = 95dB) at say 20Hz in a closed box... is only 50 watts!

So when we talk about power handling - it should always be in terms of "how low you want this speaker to play and how loud" as that is the dominant factor.

 

[Acerun]

Power handling is an interesting question. There are 2 maximums for a conventional voice coil driver. Thermally limited and mechanically limited. Here is the max SPL graph for an SB Acoustics 12" woofer. In most speaker systems it is the bass drivers that ultimately limit max SPL, as it takes 4 times the excursion (cone travel) with every halving of frequency to maintain the same SPL. This bottom attached curve is "free air" - that is no enclosure assisted power handling. What this shows is the maximum free air SPL this woofer will produce (when it runs out of cone travel) is approx 95dB at 25Hz. 20watts at 100Hz however can be played at 105dB

Now interestingly the power required to reach maximum possible excursion (and SPL = 95dB) at say 20Hz in a closed box... is only 50 watts!

So when we talk about power handling - it should always be in terms of "how low you want this speaker to play and how loud" as that is the dominant factor.
View attachment 331952View attachment 331951

I'm a dog paddler. So my two 1,000 watt Rythmik 15" subwoofers are overkill?

 

[Dave Bullet]

I'm a dog paddler. So my two 1,000 watt Rythmik 15" subwoofers are overkill?

If you like +110dB at 10Hz - then they are whimpy .

Seriously - if they go loud and clean, then they are good enough. Can't tell what Max SPL they are capable of and I'm personally not interested in anything below about 25Hz. Room gain helps heaps here too

 

[Acerun]

If you like +110dB at 10Hz - then they are whimpy .

Seriously - if they go loud and clean, then they are good enough. Can't tell what Max SPL they are capable of and I'm personally not interested in anything below about 25Hz. Room gain helps heaps here too

Ha. I am into quality and headroom. Don't listen to much higher than 80db. These measure down below 20 so they seem pretty nice. I've got them on the left and right sides of the room in the middle so smooth response.

I really like the NCX500 amps but my rational brain is telling me I'm not going to hear the difference for that extra $.

 

[bodhi1165]

This is a review and detailed measurements of the AUDIOPHONICS MPA-S250NC stereo Ncore class D amplifier. It is on kind loan from a member and costs 415,83 € tax excl. (US $444).
View attachment 290337
The enclosure is absolutely adorable! While it is fair bit deep, the other two dimensions are quite small. Combined with the low weight of the unit, you feel like buying a dozen to spread around the house and two to take on the road with you! The power button feels quite nice. The rear terminals exude quality and would rival and beat what you find on many expensive amplifiers:
View attachment 290338
Nice to see trigger input as well.

Inside a Hypex NC252MP amplifier module with integrated switching power supply. In use the bottom front got somewhat warm but nothing of concern. Protection circuit is robust and auto recovers from overloads.

If you are not familiar with my amplifier measurements, I highly suggest watching this video on amplifier measurements.

AUDIOPHONICS MPA-S250NC Measurements
Let's start with our dashboard:
View attachment 290340

That is very competent performance as far as noise+distortion (SINAD):
View attachment 290341

Zooming in:
View attachment 290342

Noise performance is excellent:
View attachment 290343

Class D designs can suffer from load dependencies but we can count on Hypex modules to be free of this:

View attachment 290344

Crosstalk is very good despite both channels being on the same module:
View attachment 290345
Multitone test showcases the low distortion:
View attachment 290346

Dual tone 19+20 kHz shows the same:
View attachment 290347
Only a couple of sidebands are visible at -98 dB and lower in audible band.

Power curve was very clean with 4 ohm load:
View attachment 290349

But strangely rose a bit with 8 ohm load:
View attachment 290348

Back to 4 ohm, we almost get the specified level of power:
View attachment 290350

I was pleased with rather smooth power vs distortion vs frequency:
View attachment 290351

The MPA-S250NC passed my stress test with reactive loads of 4 and 8 ohm but shut down into 2 ohm:
View attachment 290352

There is fair bit of pop on and off noise:
View attachment 290353

Finally, the amplifier is stable and ready to go on power on:
View attachment 290354

Conclusions
Audiophonics has produced one adorable stereo amplifier! I just want to sit there and look at it. Fortunately beauty goes beyond the skin, sporting a performance Hypex class D amplifier, producing top class results in all the measurements. You get near state of the art performance at bargain prices with scant space needed to dedicate to the amplifier.

I am happy to recommend the AUDIOPHONICS MPA-S250NC. Can't stop smiling.....

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I'm a bit unsure of the input impedance, of this amp in ohms? Will a 100ohm preamp output impedance match this amp?

 

[NTK]

I'm a bit unsure of the input impedance, of this amp in ohms? Will a 100ohm preamp output impedance match this amp?

Zero problem with the output impedance. This amp is basically a Hypex NC252MP put in a metal case, and the input impedance of the Hypex module is 47 kohm (input pin to ground).

 

[bodhi1165]

Zero problem with the output impedance. This amp is basically a Hypex NC252MP put in a metal case, and the input impedance of the Hypex module is 47 kohm (input pin to ground).

View attachment 334737

Thank you!!

 

[Chromatischism]

Getting a 2nd one of these to run my center speaker has been on my wish list ever since I got the first one a few years ago. Nevertheless, I haven't spent the money yet because I haven't detected problems from my Denon providing the power.

 

[jools]

Not sure if this is the right place and I'm sad to post this but...

The power button on my Audiophonics MPA-S250NC died. I contacted Audiophonics who pointed out that it was out of warranty (quite true, it is 3 years old). I asked if they could supply the part as I was fine with replacing it myself and they gave me a link to the item on their website. So far so good except that there was no interest in what had gone wrong - I would estimate that the number of cycles on the switch was definitely less than once per day so it failed after less than 1000 cycles. I would expect a conscientious manufacturer to either be curious about that or (if they know they have a problem) to have a large box of them on hand to send out to people...

I was unable to check out the switch from the Audiophonics website because they have a minimum order of €160 and €160 seems like a lot for a replacement switch that (although out of warranty period) really shouldn't have failed. When I asked them, they said this was purely a policy for the UK post Brexit, so others may receive less ****** service, but they were still unwilling to send me a replacement switch for under €160 (plus quite a hefty delivery charge... plus 20% VAT when it arrives because I'd paid so much for it in the first place). They also gave no information about an alternative source.

In their message they said that this was, 'To make the processing of UK orders easier on our part'. So... to make things easier for them I can go f**k myself, as presumably can anyone else who who might need a part for one of their products.

It turns out it wasn't hard to find a close match for the switch but I couldn't find one with the same flat bezel so the new one isn't exact... on the other hand I went with an orange LED which I like and toned down the searing brightness at the same time, so all is well for now but if I have a module problem I know there will be no backup at all.

I've been vaguely beginning to think about a Purifi upgrade. If (who am I kidding?...when) it happens, it will not be from Audiophonics.

 

[PDS]

I'm sorry to hear about that. That kind of behavior is so disappointing.

 

[Talisman]

You are not the only one who has heard of problems with the power button, to try to avoid problems I am using the 12V trigger so as not to have to press that button daily, however a reviewable policy and I hope that the new models have solved this problem.

 

[Acerun]

You are not the only one who has heard of problems with the power button, to try to avoid problems I am using the 12V trigger so as not to have to press that button daily, however a reviewable policy is I hope that the new models have solved this problem.

The Power switch on the back of one of mine is loose. I honestly think they just slap them into the box.

I also have upgraded to the Apolon Purifi stereo for my mains. Don't let anyone tell you that you can't hear the difference. Amazing and now only around $1000 US.

BTW, before the Apolon I bought a 3 channed Purifi from Audiophonics. Nothing but problems and radio signal interference. Returned it. Never Audiophonics again.

 

[TheWalkman]

Not sure if this is the right place and I'm sad to post this but...

The power button on my Audiophonics MPA-S250NC died. I contacted Audiophonics who pointed out that it was out of warranty (quite true, it is 3 years old). I asked if they could supply the part as I was fine with replacing it myself and they gave me a link to the item on their website. So far so good except that there was no interest in what had gone wrong - I would estimate that the number of cycles on the switch was definitely less than once per day so it failed after less than 1000 cycles. I would expect a conscientious manufacturer to either be curious about that or (if they know they have a problem) to have a large box of them on hand to send out to people...

I was unable to check out the switch from the Audiophonics website because they have a minimum order of €160 and €160 seems like a lot for a replacement switch that (although out of warranty period) really shouldn't have failed. When I asked them, they said this was purely a policy for the UK post Brexit, so others may receive less ****** service, but they were still unwilling to send me a replacement switch for under €160 (plus quite a hefty delivery charge... plus 20% VAT when it arrives because I'd paid so much for it in the first place). They also gave no information about an alternative source.

In their message they said that this was, 'To make the processing of UK orders easier on our part'. So... to make things easier for them I can go f**k myself, as presumably can anyone else who who might need a part for one of their products.

It turns out it wasn't hard to find a close match for the switch but I couldn't find one with the same flat bezel so the new one isn't exact... on the other hand I went with an orange LED which I like and toned down the searing brightness at the same time, so all is well for now but if I have a module problem I know there will be no backup at all.

I've been vaguely beginning to think about a Purifi upgrade. If (who am I kidding?...when) it happens, it will not be from Audiophonics.

Joola,

FWIW, I’m a happy Audiophonics customer (HPA-S400ET - Purifi) and hate to hear how this played out. At the very least, I’d hope they’d at least sell a replacement switch for a reasonable amount or share an OEM part number and point you to the switch manufacturer so you could buy one directly.

Customer acquisition in competitive markets is tough and a company’s reputation is easily tarnished a situation like this. Though it’s a pain in the neck for a small manufacturer to deal with, by making a small concession and assisting you in fixing this can easily make them look like a hero rather than a company you want to avoid.

Case in point: Topping‘s PA5 SNAFU with their encapsulated op amps. What a mess that is.

I’m hoping @daniboun happens to see this. I believe he lives in France and seems to know the folks over at Audiophonics. Perhaps he’ll let them know they have a chance to turn this around before this ends up hurting their longterm sales to this community.

 

[daniboun]

Joola,

FWIW, I’m a happy Audiophonics customer (HPA-S400ET - Purifi) and hate to hear how this played out. At the very least, I’d hope they’d at least sell a replacement switch for a reasonable amount or share an OEM part number and point you to the switch manufacturer so you could buy one directly.

Customer acquisition in competitive markets is tough and a company’s reputation is easily tarnished a situation like this. Though it’s a pain in the neck for a small manufacturer to deal with, by making a small concession and assisting you in fixing this can easily make them look like a hero rather than a company you want to avoid.

Case in point: Topping‘s PA5 SNAFU with their encapsulated op amps. What a mess that is.

I’m hoping @daniboun happens to see this. I believe he lives in France and seems to know the folks over at Audiophonics. Perhaps he’ll let them know they have a chance to turn this around before this ends up hurting their longterm sales to this community.

I read your misadventures and Audiophonics is uncompromising on the return and after-sales service policy. I myself had to pay additional shipping costs for an order that was unbundled due to lack of stock.... Even if the level of Audiophonics after-sales service remains satisfactory, I have the feeling that they have hardened and are less flexible than before. ...

Speaking of the front power switch: the reason why I no longer use one on my DIY projects is because I had the same problem that it mentioned on my NC500mp and a Purifi from another assembler. For me nothing better than an IEC plug with an integrated ON/OFF switch )

 

[Chromatischism]

Mine is still working perfectly as a counterpart to my Denon X4500H. 12v trigger so I never have to touch it. I put gaffer tape over the LED to tone it down.

 

[jools]

point you to the switch manufacturer so you could buy one directly.

It seems like I'm far from the only one to have a dud switch - which perhaps suggests that an exact replacement might not be the best - but once I swapped the switch and had the original out I could see that it was made by Lanboo. There no marked part number but they have a store on Aliexpress, so if anyone needs one I'm sure you can get it there.

The switch I put in was a SmartSwitch Halo which looks like it must be a rebadged version of the same switch - the plastic parts look like they came from the same moulds. These were on eBay in UK. (If anyone is shopping for one of these be a little careful - I needed one with 19mm thread diameter and 22mm bezel diameter and sometimes that was called a 19mm and sometimes a 22mm. I think there's also a version with a 22mm thread and 25mm bezel so it could be quite easy to get the wrong one.)

They may not last very long but the good news is that they're inexpensive and easy to change.

 

[tsfreo]

Not sure if this is the right place and I'm sad to post this but...

The power button on my Audiophonics MPA-S250NC died. I contacted Audiophonics who pointed out that it was out of warranty (quite true, it is 3 years old). I asked if they could supply the part as I was fine with replacing it myself and they gave me a link to the item on their website. So far so good except that there was no interest in what had gone wrong - I would estimate that the number of cycles on the switch was definitely less than once per day so it failed after less than 1000 cycles. I would expect a conscientious manufacturer to either be curious about that or (if they know they have a problem) to have a large box of them on hand to send out to people...

I was unable to check out the switch from the Audiophonics website because they have a minimum order of €160 and €160 seems like a lot for a replacement switch that (although out of warranty period) really shouldn't have failed. When I asked them, they said this was purely a policy for the UK post Brexit, so others may receive less ****** service, but they were still unwilling to send me a replacement switch for under €160 (plus quite a hefty delivery charge... plus 20% VAT when it arrives because I'd paid so much for it in the first place). They also gave no information about an alternative source.

In their message they said that this was, 'To make the processing of UK orders easier on our part'. So... to make things easier for them I can go f**k myself, as presumably can anyone else who who might need a part for one of their products.

It turns out it wasn't hard to find a close match for the switch but I couldn't find one with the same flat bezel so the new one isn't exact... on the other hand I went with an orange LED which I like and toned down the searing brightness at the same time, so all is well for now but if I have a module problem I know there will be no backup at all.

I've been vaguely beginning to think about a Purifi upgrade. If (who am I kidding?...when) it happens, it will not be from Audiophonics.

My Audiophonics amp is about 6 months old and I have only moved to using a 12v trigger on it about a month ago. Might turn out that moving to a trigger setup rather than using the power button will be a good move in the longer run....
I'm in Western Australia, so a long way for replacement parts to come.

 

[TheElementOfSurprise]

I'm having a (what I think is a Grounding) issue with my Audiophonics MPA-S250NC XLR amp, connecting to my active sub's speaker level inputs (RSL Speedwoofer 10s).

Setup: Source = PC > Duok U2 PRO XMOS XU208 Digital Interface > Schiit Modi DAC > Schiit Loki preamp > Schiit Vali2+ headphone/preamp > Audiophonics MPA-S250NX XLR Amp > Speakers (RCA/Banana Plug from Amp's Output)
> RSL Sub, Speaker Level In (Spade Connectors also coming from the Amp's same Output)

• When I make the connection to any of the Sub's Speaker Level Inputs I get a significant, constant humming from the subwoofer. I am reasonably sure this is a grounding issue.
• It occurs even when the amplifier is Audiophonics amp is powered off
• Both the sub and amp are connected to the same outlet (power strip)
  • I tried connecting the sub to an entirely different outlet, issue remained
• I was using a different amp recently that has a dedicated sub out (RSL ia255.1) without any hum, I just tried upgrading to the Audiophonics and from my research this spade connection to sub speaker level in seemed like the simplest way to connect my sub. I don't have any other available connections on my preamps in this setup.

Since discovering the issue and doing some research, I'm reading that some Class D amp's black speaker terminals are not actually grounded, rather both terminals of each output are active. Is this the case with my Audiophonics amp? If so this means I have a grounding issue, is there an easier/cleaner solution than buying a Line Out Converter?

Thanks in advance!