Hypex NCx500 Class D Amplifier Review

[soerenssen]

@boggit10 What are the available gain settings on the 3-channel Nord NCx500 MKI? According to the specs sheet they are 12.4 / 21.9 /27.0 /30.2 dB, but according to Amir's review and the Buckeye specs sheet the Hypex onboard buffer stage offers only low and high settings.
Under the Specifications (per channel) it mentions "3 x Uses Onboard NCx500 Buffer and Nord Input Connection Boards", but under the Features/Components it says "Nord REV D Input Buffer (with choice of Op Amps)". Does this custom input buffer replace the Hypex buffer stage and if yes, can the gain be configured per channel?

Nord One NCx500 3CH 3 Channel Power Amplifier

The Nord One 3CH 3 Channel NCx500 amplifier. Consisting of separate amp module’s, PSU’s and Nord connection input/output boards Designed for high end LCR AV use, Matches our MP range of multi channel amps perfectly. Using onboard NCx500 buffers and is linked to the rest of the amp via a Nord...

nordacoustics.co.uk

 

[ommadusk]

@boggit10 What are the available gain settings on the 3-channel Nord NCx500 MKI? According to the specs sheet they are 12.4 / 21.9 /27.0 /30.2 dB, but according to Amir's review and the Buckeye specs sheet the Hypex onboard buffer stage offers only low and high settings.
Under the Specifications (per channel) it mentions "3 x Uses Onboard NCx500 Buffer and Nord Input Connection Boards", but under the Features/Components it says "Nord REV D Input Buffer (with choice of Op Amps)". Does this custom input buffer replace the Hypex buffer stage and if yes, can the gain be configured per channel?

Nord One NCx500 3CH 3 Channel Power Amplifier

The Nord One 3CH 3 Channel NCx500 amplifier. Consisting of separate amp module’s, PSU’s and Nord connection input/output boards Designed for high end LCR AV use, Matches our MP range of multi channel amps perfectly. Using onboard NCx500 buffers and is linked to the rest of the amp via a Nord...

nordacoustics.co.uk

I think the Hypex low gain is always there and an op amp replaces the high gain. I think Nord have made a mistake there but you'll have to check with them. So I think it's only two gains, which may be enough. I have to tell you I love my Audiophonics stereo amp and the buffer settings are very good, I use the (edit) first gain setting. I think the gain setting can be changed per channel. It can on the Audiophonics. I did try the second gain setting but it didn't sound as good but I'm not sure about that it may be bias.

The Audiophonics uses the same op amp as the HPA-S400ET which got excellent reviews here. You could email Audiophonics and ask if they'll make a mono amp for you, ask Nord if they can put in an op amp in, or get the amps from Apollon. I don't know they might say yes. I think Apollon and Nord use the op amp that didn't get as good a review here. Apollon claimed it's better to me when I messaged them. There may be other options as well. I think NCX500 is quite new so more amps will become available in time. By the way, I'm not suggesting you get the NCX500 over other amps.

 

[soerenssen]

I think the Hypex low gain is always there and an op amp replaces the high gain. I think Nord have made a mistake there but you'll have to check with them. So I think it's only two gains, which may be enough. I have to tell you I love my Audiophonics stereo amp and the buffer settings are very good, I use the (edit) first gain setting. I think the gain setting can be changed per channel. It can on the Audiophonics. I did try the second gain setting but it didn't sound as good but I'm not sure about that it may be bias.

The Audiophonics uses the same op amp as the HPA-S400ET which got excellent reviews here. You could email Audiophonics and ask if they'll make a mono amp for you, ask Nord if they can put in an op amp in, or get the amps from Apollon. I don't know they might say yes. I think Apollon and Nord use the op amp that didn't get as good a review here. Apollon claimed it's better to me when I messaged them. There may be other options as well. I think NCX500 is quite new so more amps will become available in time. By the way, I'm not suggesting you get the NCX500 over other amps.

I asked, they are not planning to make a mono version.

 

[ommadusk]

I asked, they are not planning to make a mono version.

That's a pity.

 

[ommadusk]

Audiophonics now has a NCx500 amplifier for roughly the same price as the Purifi.

AUDIOPHONICS HPA-S600NCX Power Amplifier Class D NCore NCx500 2x600W 4 Ohm - Audiophonics

The Audiophonics HPA-S600NCX dual mono power amplifier, an updated and improved version of the HPA-S600NC, is now equipped with Hypex NCore NCx500 amplifier modules. These provide twice the performance in terms of distortion and output impedance

www.audiophonics.fr

Unfortunately I've had this amplifier for a few days, I had a few problems with the left channel yesterday which I didn't pinpoint on the amplifier and today the right channel's cut out. I've emailed Audiophonics.

Edit. I've spoken to them and they asked me to check a few things and the XLR just started working again. So I'm waiting and seeing if the problem reappears.

 

[ClaudeJ1]

Isn't testing this unbuffered a bit unfair for comparison? How useful is a power amp with just 12 dB of gain and what is the input impedance in this config?

It's perfect if you have all horns from 80Hz to 20Khz.! Like the EdgarHorn Titan II's.

 

[soerenssen]

Unfortunately I've had this amplifier for a few days, I had a few problems with the left channel yesterday which I didn't pinpoint on the amplifier and today the right channel's cut out. I've emailed Audiophonics.

Edit. I've spoken to them and they asked me to check a few things and the XLR just started working again. So I'm waiting and seeing if the problem reappears.

Is the issue gone since then?

I wanted to ask you about the trigger input. Mine has a button at the front but no 0/1 switch at the back. Amp is connected via 3.5mm mono cable to the AVR's trigger out, but it doesn't seem to do anything. If the amp's front button is off, the amp is not triggered. If the button is on, it's turned on. How do you know if it is in standby mode and if it was triggered successfully?

 

[ommadusk]

I'm sure it was to do with my DAC and not the amplifier. The problem's still happening.

On the 12v trigger mine doesn't work also! I've just sent a message to Audiophonics about it. In order for it to work you've got to have the front button on. If it's triggered the button light will go off when you turn off the power on your AVR or it will light up when you turn the power on. So it's not working? I'm assuming the top socket is the input??

Do you have the same amp as me? https://www.audiophonics.fr/en/powe...lass-d-ncore-ncx500-2x600w-4-ohm-p-17591.html

Edit. Just a thought. Do you need to switch the 12v trigger function on on your AVR, I have to that on my DAC?

 

[soerenssen]

In order for it to work you've got to have the front button on. If it's triggered the button light will go off when you turn off the power on your AVR or it will light up when you turn the power on. So it's not working? I'm assuming the top socket is the input??

Do you have the same amp as me? https://www.audiophonics.fr/en/powe...lass-d-ncore-ncx500-2x600w-4-ohm-p-17591.html

Same amp. It's the other way around, actually. Audiophonics replied and they confirmed that you have to turn off the amp using the button and the trigger device should turn it on (LED light will turn on, depending on your jumper setting at the bottom). In my case, the Denon AVR had the wrong trigger settings (trigger based on HDMI monitor 1 and HDMI monitor 2). I noticed that once I turn on the TV, the AVR triggers the amp. When I turn the TV off, the AVR turns off the amp. So I removed HDMI from the list of trigger input list and it's now working fine.

 

[ommadusk]

That's great, now mine works too! I assumed it was the other way round. Are you pleased with the amp?

 

[soerenssen]

That's great, now mine works too! I assumed it was the other way round. Are you pleased with the amp?

That's great!
I'm quite happy with the x4800h + stereo NCx500 combo. The area of the NCx500 amps gets warm to the touch at higher volumes but not hot. The area of the power supply stays cool all the time. It can easily move the alu membranes of the KEFs and it's definitely not the limiting factor in my setup. Its case is not as nice as the rest of the setup and it takes up a considerable amount of space in my hifi stand under the TV, but I'll keep it because I like the robustness and good thermal properties. Next step will be Dirac and some passive room treatment (I have lots of echo here in the living room / kitchen area and I'm not sure if Dirac alone can tame that). We are moving later this year and a good room for these speakers will be my next big "upgrade". I cannot compare the amp to Purifi or Nilai (the former supposed to be better "musically", according to Audiophonics), but honestly I am not missing anything that was there in the showroom, at least my ears are not that good to notice the difference (besides the showroom having a better room with carpet everywhere).

I just wanted to thank for all the help to this community, also to @Audiophonics and especially to @Apollon Audio for their support and for going the extra mile while helping me to decide!

 

[ommadusk]

That's great!
I'm quite happy with the x4800h + stereo NCx500 combo. The area of the NCx500 amps gets warm to the touch at higher volumes but not hot. The area of the power supply stays cool all the time. It can easily move the alu membranes of the KEFs and it's definitely not the limiting factor in my setup. Its case is not as nice as the rest of the setup and it takes up a considerable amount of space in my hifi stand under the TV, but I'll keep it because I like the robustness and good thermal properties. Next step will be Dirac and some passive room treatment (I have lots of echo here in the living room / kitchen area and I'm not sure if Dirac alone can tame that). We are moving later this year and a good room for these speakers will be my next big "upgrade". I cannot compare the amp to Purifi or Nilai (the former supposed to be better "musically", according to Audiophonics), but honestly I am not missing anything that was there in the showroom, at least my ears are not that good to notice the difference (besides the showroom having a better room with carpet everywhere).

I just wanted to thank for all the help to this community, also to @Audiophonics and especially to @Apollon Audio for their support and for going the extra mile while helping me to decide!

You made me decide to get the Audiophonics HPA-S400ET to compare. I've posted a thread about it here

The state of the art class D AUDIOPHONICS HPA-S600NC and AUDIOPHONICS HPA-S400ET sound different, though there is a caveat here.

Hi, I have both these amplifiers in my possession so I've been able to compare them. It's not blind tested. I originally got the NcoreX a couple of weeks ago and I had the Purifi held in customs for a time and I decided at the last minute to get the Purifi as well. It's common belief here that...

audiosciencereview.com

I definitely prefer the Purifi.

 

[Megaken]

Does anyone in Philly have a purifi amp? I have NCx and want to compare too. I'd bring you mine or you can bring me yours.

 

[soerenssen]

The state of the art class D AUDIOPHONICS HPA-S600NC and AUDIOPHONICS HPA-S400ET sound different, though there is a caveat here.

(some people claim, without evidence, to hear a difference, others don't Fixed it for you.

audiosciencereview.com

Hypex NCx500: Often described as neutral and transparent, this module is regularly perceived as analytical by some listeners including myself, signifying its ability to reproduce recordings without adding any coloration. However, it's worth noting that with certain operational amplifiers, such as the LM4562 and similar types, the NCx500 can come across as slightly harsh in the high mids and highs. In my experience, this module pairs optimally with op amps like OPA1612, OPA1656, Weiss OP2-BP and similar, which tend to present a more refined sound profile.

@Apollon Audio It's nice to have some insight about the differences in sound using these op amps. How do they compare to the onboard Hypex buffer @amirm was using in his review? Is it not recommended or any other reason why it cannot be chosen as an option?

 

[Julf]

It's nice to have some insight about the differences in sound using these op amps

Would be even better to have some measurements and objective verification.

 

[soerenssen]

Would be even better to have some measurements and objective verification.

Starting out of the base implementation from Hypex (measured already) and paired with speakers that respond well to EQ, I was just wondering why one must choose an op amp. I feel it should be an additional option, in case one wants to swap them to tune the amp's sonic signature to his/her taste, but I'm also curious how the base version sounds as it is before changing anything.

 

[Julf]

Starting from the base implementation from Hypex (measure already) and paired with speakers that respond well to EQ, I was just wondering why one must choose an op amp. I feel it should be an additional option, in case one wants to swap them to tune the amp's sonic signature to his/her taste, but I'm also curious how the base version sounds as it is before changing anything.

Wouldn't tone controls, EQ ore DSP be better for that?

 

[soerenssen]

Wouldn't tone controls, EQ ore DSP be better for that?

That'd be the idea. Unless someone needs variable gain settings, the extra cost of the op amps could be saved.
It would be good if the manufaturers could provide some clarity on this. If it's really a no-brainer, because the Hypex alone is unlistenable, then case closed. But then @amirm would've at least mentioned this in the review.

 

[Rob Fens]

That'd be the idea. Unless someone needs variable gain settings, the extra cost of the op amps could be saved.
It would be good if the manufaturers could provide some clarity on this. If it's really a no-brainer, because the Hypex alone is unlistenable, then case closed. But then @amirm would've at least mentioned this in the review.

Hi Soerenssen,
When reading this Forum i get the general idea; All poweramps with the same measured values, sound the "same" (not significantly worse than its competitors, which is close to what you call unlistenable). Furthermore; untill your post, every user in this thread seemed pretty positive about this amp. How come you reached your bold statement?
Regards,
Rob.

 

[soerenssen]

Hi Soerenssen,
When reading this Forum i get the general idea; All poweramps with the same measured values, sound the "same" (not significantly worse than its competitors, which is close to what you call unlistenable). Furthermore; untill your post, every user in this thread seemed pretty positive about this amp. How come you reached your bold statement?
Regards,
Rob.

I was also happy with the amp while I had it, although it had a TI op amp and custom buffer board.
It was a question, not a statement: if the the Hypex buffer is already good enough, then why would it require a new buffer board with op amps (as non-optional extras)? Is it only because of the additional flexibility having more gain settings and the ability to change the sound? I'm just curious: if someone needs only the fixed default gain of 27dB and doesn't need an op amp, why cannot it be chosen as an option? I think maybe Nord sells the MKI version with the default Hypex buffer and fixed gain. I think there wouldn't be an option available to buy the basic version if the Hypex buffer didn't sound good enough. I think this is what you misunderstood. I'm not a native English speaker, apologies if it was not clear.