Hypex NCx500 Class D Amplifier Review

[Toni Mas]

That’s it folks, power amplification is a solved issue now. Pack your bags and move on to something else.

Many thanks to both Rick and Amir for making this review possible.

Not yet! That power is overkill for me, and price also an issue. What i need is a 30 watter with same performance for under 100€

 

[Joe Smith]

Q: Is there a current Hypex-based fully-assembled & US-available unit that gives about 100 wpc for 8 ohm speakers? I'm contemplating a future purchase, but my speaker/room demands don't really need more than that, even allowing for headroom. I'd like to step up from the Class D ~50 wpc amps I am using now....attracted to the Buckeye or VSV lineups and functionality but seeking something in the $300 - 500 price range?

 

[HarmonicTHD]

Could I use this as a bass amp?

Recently many companies have developed many preamp style pedals that make the eq section of bass amps redundant and the option of being able to leave the Poweramp section with the cabinets at the studio and moving just the preamp pedal with me when going home is quite convenient, but the problem us that most poweramps in the market are still AB, very heavy and bulky, and not linear at all, specially in the bass region.

For a dedicated sub amp I would even go higher power (500 to 1000W or more) - depends of course on the driver etc. and your SPL requirements. Also for sub amps, amp distortion is less critical. First humans are less sensitive to distortion at low frequency and secondly the distortion added by the driver will be orders of magnitudes higher anyway. You don’t need the SINAD king for that.

 

[YSC]

Thing to bear in mind - all manufacturers can be subject to these problems. Only 3 years ago, Hypex were shipping modules with some fairly dodgy design flaws resulting in reliability issues as identified by our own @restorer-john . No idea if they've fixed is since then - hopefully they have.

However, as you say a key differentiator is how an organisation responds when something does go wrong. Hypex have a good track record here. Topping does not.

https://audiosciencereview.com/foru...d-amp-long-term-reliability.25744/post-879401

yea I think I remember the Hypex sega back then, but it's always the response make one's feeling differs from "I spent my money well and they are keen to resolve problem" to "you just give the budget cost, and gamble on luck that it don't go in flames in a short while"

 

[Rick Sykora]

@Rick Sykora please give us a little explanation. What type of building blocks are populated on the "interface board" for me, it seems the "buffer" is on the power module?
would be great because no assembler can mess it up.

Correct, the interface board used here is the original NC500 eval board modified by Hypex for the NCx500.

Afaik, the differences are that buffer op amp has been removed and the jumpers set to use the regulators on the amp module.

P.S. PLEASE NOTE THE FOLLOWING

Post #175 in this thread (now removed) mods are questionable at best as those instructions are NOT Hypex's instructions. The actual mods were done by Hypex for me, but if you have an unmodified board, here are the mods needed:

1. Set the solder jumpers J15 & J16 on Unbuffered.
2. Solder R7 & R8 jumpers to bypass the TO220 voltage regulators.
3. Because voltage regulators are bypassed, the opamp (U3) will receive to high voltage and can break down. So, remove the opamp on the evaluation board as well.

Here is a pic with the mods higlighted:

 

[BR52]

Many thanks!

 

[phoenixdogfan]

As a practical matter, the fact distortion rises between 200-500 watts is probably not that important. Most of the listening will be done at 1-5 watts anyway, and if you have a speaker capable of using the full 500 watts, it will still probably be the cleanest, most effortless 105-110 db peaks you will ever hear in your listening room.

 

[HarmonicTHD]

As I read your posts I am realizing I am getting lost in the technical aspects of gain, voltages and signal paths. Can you recommend me where to read a 101 guide on gain and the relation between preamps and amps?

I am not John….

2V Input Voltage x 12 dB Gain (x 3.98) = ca 8V Output Voltage

Power at 8 ohm = 8 V Output Voltage ^ 2 / 8 Ohm = 8 W :-(

You can run the numbers with higher Input voltage eg 4V (ca 32W in 8 Ohms).

The AHB2 performs its magic (best SINAD) at 26 dB gain (Edit: correction. 26dB is not correct it was low gain so full power was achieved at 9.8 Input Voltage. So indeed comparable with the unbuffered amp here).

 

[VintageFlanker]

Preamps are a very small part of the market

Guess what: This kind of assembled nCore amps also are a very small part of the market.

 

[Toni Mas]

Guess what: This kind of assembled nCore amps also are a very small part of the market.

I guess a niche market for pro and power hungry users

 

[DTTOM37]

Q: Is there a current Hypex-based fully-assembled & US-available unit that gives about 100 wpc for 8 ohm speakers? I'm contemplating a future purchase, but my speaker/room demands don't really need more than that, even allowing for headroom. I'd like to step up from the Class D ~50 wpc amps I am using now....attracted to the Buckeye or VSV lineups and functionality but seeking something in the $300 - 500 price range?

Check out this one:
NC250
or the lower powered NC125

AUDIOPHONICS MPA-S125NC XLR Stereo Class D Power Amplifier NCore 2x125W 4 Ohm - Audiophonics

The Audiophonics PAS-125NC incorporates a Hypex Ncore NC122MP power amplifier module. This is a solid base to build a powerful stereo HiFi system, capable of delivering 2x75W under 8Ω.

www.audiophonics.fr

 

[capslock]

Well, noise performance compared to Purifi is impressive. Question remains: is there an audible benefit?

Regarding distortion, I think I would still prefer the Purifi. The NCx has slightly higher 2nd order distortion, 3rd is comparable, but then it has all those higher harmonics at -130 to -135 dB where there is absolutely nothing for the Purifi.

It's also that the amp looks like it was engineered for Amir's 5 W test, with distortion rising steeply after 6 W. Not that it matters much in a home enviroment, but in a PA setup, the Purifi is so much better almost up to its rated power.

Now the Nilai amps seem to play in a wholly differnt leage. Any word about their availability and pricing?

DIYClassD is the DIY branch of Hypex Electronics BV for audiophile lovers.

Aimed at the DIY market we use Hypex Class D power amplifiers, power supplies, DSP solutions and plate amplifiers for HiFi and High End applications.

www.diyclassd.com

Edit: seems like it was availabe for a time and the next batch will become available March 31:

DIYClassD Nilai500DIY 500W mono power amplifier kit

The DIYClassD Nilai500DIY 500W Mono power amplifer kit is easy to assemble and enables you to build a high-end mono amplifier at a fraction of the costs

www.diyclassd.com

 

[Matias]

I guess a niche market for pro and power hungry users

A reader of ASR should be knowledgeable enough to add an RME ADI-2 DAC to this amp as endgame. Not many in the overall market though, I agree.

 

[MZKM]

Yes, but I meant that you can't really overlay these graphs on top of each other when you compare different amplifiers because its not a single line. You always have to keep them next to each other.

Just open them in different tabs and switch.

 

[Vacceo]

I am not John….

2V Input Voltage x 12 dB Gain (x 3.98) = ca 8V Output Voltage

Power at 8 ohm = 8 V Output Voltage ^ 2 / 8 Ohm = 8 W :-(

You can run the numbers with higher Input voltage eg 4V (ca 32W in 8 Ohms).

The AHB2 performs its magic (best SINAD) at 26dB gain (I might be wrong as I am quoting from memory). With a gain ca 5 times higher, noise increases. That’s why many think the comparison with the Benchmark is unfair, unless we see the SINAD at a comparable gain as Amir promised for the next days (including the buffer board).

Good enough, thanks! So esentially the point of any amp is trying to reduce the gain as much as possible to also reduce noise and distortion; but the problem is that it still needs a high output from a preamp which is typically not the case for home audio gear (from what I have seen 2 to 5V being 2 and around are the most common). Right so far?

 

[HarmonicTHD]

Good enough, thanks! So esentially the point of any amp is trying to reduce the gain as much as possible to also reduce noise and distortion; but the problem is that it still needs a high output from a preamp which is typically not the case for home audio gear (from what I have seen 2 to 5V being 2 and around are the most common). Right so far?

There is no free lunch. Somewhere the gain to drive the speakers has to come from. You need to look at the SINAD over output voltage performance of both preamp and power amp to determine the “sweetspot” (best overall SINAD) - Amir provides those graphs.

But yes often this is with high preamp output voltage and minimum power amp gain. Eg with the RME and the AHB2 you can set the gain of each device to the best combination. (But let’s keep in mind we are talking transparency either way). If however you take one of the Denon AVRs in preamp mode, they exhibit an increase in SINAD past a certain output voltage, so here you would set the AHB2 to a higher gain to keep the Denon in it’s best performance range.

 

[Toni Mas]

A reader of ASR should be knowledgeable enough to add an RME ADI-2 DAC to this amp as endgame. Not many in the overall market though, I agree.

Would go for the new ADI-2/4 PRO SE and a 4 Channel Ncore amp...

 

[dtaylo1066]

Hypex amps are consistently superb! Can't wait until you test one of these:

 

[dtaylo1066]

I also see Hypex has this coming:

 

[ex audiophile]

The "pre amp guys" can read this thread:

The Signal Chain: How do noise and distortion propagate through my system?​

It can be hopefully helpful.

I don't see a link to this topic, it would be fun to read.