Hypex NCx500 Class D Amplifier Review

[boXem]

It is as if NCx500 has extra focus on reducing distortions on bass and mids (see IMD distortion at 1 kHz) a letting go earlier in treble (below 20 kHz), where musical signal is lower and the ear less sensitive. I wonder if that was a design goal.

A software engineer would tell you that this is a feature...
I see it as a consequence of a less punchy control loop compared to eigentakt and nilai.

 

[jmillar]

Not me. LA90 is stereo, though bidgeable. These Ncores mono. Nothing comparable.
But i would not buy LA90 though, too expensive and need more than 2 channels.

It's not so much the expense, but the fact that in bridged mode they unfortunately seem to require 8 Ohm speakers.

 

[DrCWO]

I wonder why the XLR body is "grounded" this way??

View attachment 257237

And why the distortion rises (even THD+N/level at 1kHz!) as early as above 5-10W??

Any, answers, @Hypexsales ?

Because it is completely correct!
Please take a look here.

 

[Julf]

here
Please take a look here.

And here. By the guy who designed the amps.

 

[Don Kuleone]

NCx500 ship from Hypex on the 21-4-23

Did Hypex ship already?

 

[DrCWO]

Did Hypex ship already?

Seems so. I bought an amplifier with it at Rouge Audio and according UPS tracking it is on its way to Germany now

 

[Rick Sykora]

Did Hypex ship already?

There were some limited NCx500 samples available early 2022. The first full production run was later.

I did not get any until November. Nord may have gotten an early sample though.

 

[fpitas]

Yeah, who cares about what's actually audible.

Why do you hate your dog?

/

 

[SIY]

Why do you hate your dog?

/

 

[Matias]

For reference below is Apollon's new entry level amp using a single PS to power 2 NCx500 modules. Notice that it does 2 x 645W = 1290 W with a PS rated at 1200W, so it does have headroom to drive both modules to almost full power. And the FFT shows some distortions less in the same low gain but using Apollon's buffer.

Apollon Audio Class-D Amp Build Quality

read again :) Ok, is the difference ... got it. Sorry.

www.audiosciencereview.com

 

[DrCWO]

Received mine from Rouge Audio yesterday.

I requested a custom build with:
- WBT Binding posts
- Neutik XLR connectors
- Only one Power supply (My horn speakers are 16Ohm so I need the voltage but with less power)
- An additional trigger input that works with 5V
- White frontplane with custom engraving
- No power switch at the front

The amp arrived very well packaged and worked flawlessly right out of the box. I'm going to be running it for a few days now to burn it in before critical listening.

The housing is made of sheet steel. Technically great but missing some glamor and the feeling of high-end quality.

The trigger input is galvanically isolated from the amp to avoid ground loops I was wondering about the funny non-standard connector they used for the trigger. It's a connector you'd typically see on power adapters rather than the standard 3.5mm plug. The trigger board completely removes power instead of using the SMPS1200's standby functionality. Maybe they offer that too, but I didn't ask. In the beginning the trigger was only designed for 12V but I need it to work with 5V as well. Francesco was kind enough to switch it to 5V. I really appreciate that he didn't ask for an extra fee for this change!

Like to share some photos here.

 

[JeyB]

Seems so. I bought an amplifier with it at Rouge Audio and according UPS tracking it is on its way to Germany now

Me too, I expect to receive a power amp today, wednesday, at least this is what UPS tracking says. Two NCX500 modules with two SMPS 1200A700 power supplies. They are out of stock right now.

 

[JeyB]

Received mine from Rouge Audio yesterday.

I requested a custom build with:
- WBT Binding posts
- Neutik XLR connectors
- Only one Power supply (My horn speakers are 16Ohm so I need the voltage but with less power)
- An additional trigger input that works with 5V
- White frontplane with custom engraving
- No power switch at the front

The amp arrived very well packaged and worked flawlessly right out of the box. I'm going to be running it for a few days now to burn it in before critical listening.

The housing is made of sheet steel. Technically great but missing some glamor and the feeling of high-end quality.

The trigger input is galvanically isolated from the amp to avoid ground loops I was wondering about the funny non-standard connector they used for the trigger. It's a connector you'd typically see on power adapters rather than the standard 3.5mm plug. The trigger board completely removes power instead of using the SMPS1200's standby functionality. Maybe they offer that too, but I didn't ask. In the beginning the trigger was only designed for 12V but I need it to work with 5V as well. Francesco was kind enough to switch it to 5V. I really appreciate that he didn't ask for an extra fee for this change!

Like to share some photos here.

Hi DrCWO, thanks for the photos. I've received just now my NCx500 amp, but still hadn't the time to open the parcel

Your power amp seems to have the buffer stage bypassed at jumpers J15&J7, so it's running at 11,5 dB voltage gain instead of 26.8 dB. What preamplifier/DAC are you going to pair with this power amp? The input impedance in unbuffered setup is minimum 1.8 kohm. So I suppose your horn speakers must be on the high sensitivity side, let's say 93+ dB/1W/1m to optimally operate bufferless.

Did you experience any on/off pop sound?

Best

 

[DrCWO]

Hi DrCWO, thanks for the photos. I've received just now my NCx500 amp, but still hadn't the time to open the parcel

Your power amp seems to have the buffer stage bypassed at jumpers J15&J7, so it's running at 11,5 dB voltage gain instead of 26.8 dB. What preamplifier/DAC are you going to pair with this power amp? The input impedance in unbuffered setup is minimum 1.8 kohm. So I suppose your horn speakers must be on the high sensitivity side, let's say 93+ dB/1W/1m to optimally operate bufferless.

Did you experience any on/off pop sound?

I pair it with RME ADI-2/4 Pro, so enough output voltage for running the amp with 11.5dB amplification and no issues with input impedance
With it I can also have DRC and XO in Roon and have two outputs for the woofers and two for the horns.

Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC

(Grin) No pics of the wiring behind it all?? :rolleyes:;) Thank you again for your kind encouragements! You can find my "wiring behind" photo as of May 30 2022 in my post #540 (before the revival of LP player); please allow me showing it again here.:)

audiosciencereview.com

And yes, the horns have 98dB sensitivity.

Until now I have it in my study but with my small desktop speakers I encounter no pop at all. Will be different with the hors.
Will see after burn in.

Best DrCWO

 

[JeyB]

I pair it with RME ADI-2/4 Pro, so enough output voltage for running the amp with 11.5dB amplification and no issues with input impedance
With it I can also have DRC and XO in Roon and have two outputs for the woofers and two for the horns.

Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC

(Grin) No pics of the wiring behind it all?? :rolleyes:;) Thank you again for your kind encouragements! You can find my "wiring behind" photo as of May 30 2022 in my post #540 (before the revival of LP player); please allow me showing it again here.:)

audiosciencereview.com

And yes, the horns have 98dB sensitivity.

Until now I have it in my study but with my small desktop speakers I encounter no pop at all. Will be different with the hors.
Will see after burn in.

Best DrCWO

Thank you very much for you feedback (not negative lol).

Your system is a quite impressive and neatly organized setup The RME is a great piece of equipment, it offers fantastic flexibility with its four outputs (I wasn't aware it also offer RIAA eq. Wow, what a nice feature!). I have had my turntable out of my equation for more than ten of years ago.

I run my own multichannel system with 12 NCore channels in a stereo setup, and discretionally I can add to them another 2 more channels for two monopolar sealed subwoofers if neccesary, ah and also two more channels from a minidsp 2x4HD xover for another diffuse wavefield speakers at the end of the room that I engage in some classical music recordings to increase perceived spatiousness (still working on it). So in reality there are 16 channels for stereo. I will post some schematics and photographs in the same thread you have sent me; there are quite a lot of interesting proposals there. I have Dirac room correction applied only in the sealed monopolar subwoofers. By DRC you mean Dirac Room Correction, isn't it?

Nevertheless the NCX500 amp is dedicated to another sound system with ATC SCM50 loudspeakers.

Best

 

[Rick Sykora]

Received mine from Rouge Audio yesterday.

I requested a custom build with:
- WBT Binding posts
- Neutik XLR connectors
- Only one Power supply (My horn speakers are 16Ohm so I need the voltage but with less power)
- An additional trigger input that works with 5V
- White frontplane with custom engraving
- No power switch at the front

The amp arrived very well packaged and worked flawlessly right out of the box. I'm going to be running it for a few days now to burn it in before critical listening.

The housing is made of sheet steel. Technically great but missing some glamor and the feeling of high-end quality.

The trigger input is galvanically isolated from the amp to avoid ground loops I was wondering about the funny non-standard connector they used for the trigger. It's a connector you'd typically see on power adapters rather than the standard 3.5mm plug. The trigger board completely removes power instead of using the SMPS1200's standby functionality. Maybe they offer that too, but I didn't ask. In the beginning the trigger was only designed for 12V but I need it to work with 5V as well. Francesco was kind enough to switch it to 5V. I really appreciate that he didn't ask for an extra fee for this change!

Like to share some photos here.

Nicely jacketed wiring but looks as though more premium binding posts are squeezed into spot meant for smaller ones. Would like to see an AC fuse but can be added. Interesting that Rouge sourced power splitter from Canada but is a nice clean way to get the job done.

Thanks for sharing. Hope you enjoy it!

 

[DrCWO]

By DRC you mean Dirac Room Correction, isn't it?

Impressive
I use Acourate to compute DRC and XO as FIR filters which I run inside the Roon convolution engine.

 

[Don Kuleone]

Apollon ships my dual mono ncx500 amp propably this friday. I pair it with a miniDSP Flex TRS as pre amp. So I will have 4V output voltage. I will use 20,5db gain.

 

[Julf]

Will see after burn in.

"Burn in"?

 

[SIY]

"Burn in"?

Filters require burning in otherwise they're too raw.