Apollon NCx500ST Stereo Amplifier Review

[peng]

You are very welcome. We offer global shipping. Kindly be advised that the measurements provided pertain to the NCx500 DM dual mono version, which I have readily available in my studio. At this moment, I do not have the NCx500ST version on hand. The distinguishing feature of the dual mono version is that each NCx500 module is paired with its own dedicated Hypex SMPS1200 power supply.

We recognize the importance of these details for our customers, and thus we are in the process of updating our website to incorporate this information. It will also be included in forthcoming manuals. We appreciate your patience as we enhance our online presence.

Good to know, any know bugs of any kind so far with the mono-blocks, including the triggers?

 

[Apollon Audio]

Good to know, any know bugs of any kind so far with the mono-blocks, including the triggers?

We have not identified any issues with the mono-blocks. Their performance is consistent with that of the stereo versions. Additionally, the triggers have proven to be exceptionally reliable.

 

[Sokel]

Too be fair to @restorer-john, he is pointing out a legitimate reason why he wanted 20kHz. And he also pointed out the reason why (most) manufacturers don't do it.

But the wording did come across as lumping Apollon with other manufacturers who intentionally don't do 20kHz.

Either way, this amp is a win for consumers. Although, the dual mono, Lux version is on the pricier side. But I guess, after how Apollon showed up here, they may have earned it.

You can also see the same module here,but with broad bandwidth and much more freqs.
It depends greatly of how you measure it.
And implementations also I guess?

BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

The West Gate Bridge collapse was actually in Melbourne in 1970. As a young boy, I remember my Dad driving us along the road to the bridge, where you could walk/drive along the partially completed section and get quite close to the broken off part. It sat like that for about 2 years and was...

www.audiosciencereview.com

 

[Apollon Audio]

You can also see the same module here,but with broad bandwidth and much more freqs.
It depends greatly of how you measure it.
And implementations also I guess?

BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

The West Gate Bridge collapse was actually in Melbourne in 1970. As a young boy, I remember my Dad driving us along the road to the bridge, where you could walk/drive along the partially completed section and get quite close to the broken off part. It sat like that for about 2 years and was...

www.audiosciencereview.com

I can attest that the performance and measurements of the end product are contingent upon its implementation as well.

 

[Sokel]

I can attest that the performance and measurements of the end product are contingent upon its implementation as well.

Disregarding the rest of the freqs if we only look at some random 1Khz THD+N vs power from the many posted it doesn't seem the same.

Apollon from post #253

Buckeye from the above test (I guess same 20-20000Hz bandwidth),light green-light blue traces:

One amp has a declined THD+N slope with power,the other one is balooing.
What's different?

 

[CleanSound]

You can also see the same module here,but with broad bandwidth and much more freqs.
It depends greatly of how you measure it.
And implementations also I guess?

I can attest that the performance and measurements of the end product are contingent upon its implementation as well.

I suspect that the only part that is in the control of the manufacturer/assembler is the buffer board, since the amp module and SMSP are off-the-self directly from Hypex (exception in the case of NAD, where they just license the tech and designed their on circuit and their own SMSP). I am by no means downplaying the importance of the buffer board (that is very important since that is where the input signal passes through), I am just one inquisitive guy.

 

[Apollon Audio]

Disregarding the rest of the freqs if we only look at some random 1Khz THD+N vs power from the many posted it doesn't seem the same.

Apollon from post #253

View attachment 311564

Buckeye from the above test (I guess same 20-20000Hz bandwidth),light green-light blue traces:

View attachment 311565

One amp has a declined THD+N slope with power,the other one is balooing.
What's different?

The measurement you're referencing from my data was taken at 1kHz and utilized different operational amplifiers. It primarily serves as a comparison between these operational amplifiers. In contrast, the measurements from Buckeye's review span a range of 20Hz-20kHz. It remains uncertain to me why the performance at 1kHz doesn't align with our records. However, Amir has validated that our amplifier's performance is consistent with the metrics I've indicated.

 

[Apollon Audio]

I suspect that the only part that is in the control of the manufacturer/assembler is the buffer board, since the amp module and SMSP are off-the-self directly from Hypex (exception in the case of NAD, where they just license the tech and designed their on circuit and their own SMSP). I am by no means downplaying the importance of the buffer board (that is very important since that is where the input signal passes through), I am just one inquisitive guy.

May I suggest that factors such as the use of shielded cables, strategic module placement, cable selection and meticulous cable routing can also influence the performance disparities you've observed. It is not just how good a buffer board is designed.

 

[Sokel]

The measurement you're referencing from my data was taken at 1kHz and utilized different operational amplifiers. It primarily serves as a comparison between these operational amplifiers. In contrast, the measurements from Buckeye's review span a range of 20Hz-20kHz. It remains uncertain to me why the performance at 1kHz doesn't align with our records. However, Amir has validated that our amplifier's performance is consistent with the metrics I've indicated.

Yes,I'm talking only about the 1Khz ones,in both graphs,forget the rest.
At the first post of the Buckeye amp the graph varied with different gain too.

I think everyone here taking measurements with an AP must align with each other or we are at lost.
(@thin bLue is still new to this to his defense so still has room for improvement but has the will to learn!)

 

[Dougey_Jones]

May I suggest that factors such as the use of shielded cables, strategic module placement, cable selection and meticulous cable routing can also influence the performance disparities you've observed. It is not just how good a buffer board is designed.

Was going to make this comment, but you beat me to it.

The materials used, including solder type, wire type and gauge, binding post quality, input connectors and layout are the reasons I chose Apollon over other offerings.

 

[Apollon Audio]

Yes,I'm talking only about the 1Khz ones,in both graphs,forget the rest.
At the first post of the Buckeye amp the graph varied with different gain too.

I think everyone here taking measurements with an AP must align with each other or we are at lost.
(@thin bLue is still new to this to his defense so still has room for improvement but has the will to learn!)

Upon reviewing the measurements from @thin bLue, the primary discrepancy I've noted is the bandwidth he employs—60 kHz, in contrast to Amir and myself, who utilize 22.4kHz and 45kHz bandwidths, respectively. This choice could introduce a considerable amount of wideband noise into the measurements, which may not be reflective of an amplifier's performance within the audible frequency spectrum. It's worth noting that, like @thin bLue, I employed 100 points in the FFT for my analysis.

 

[radix]

@Apollon Audio I just want to thank Apollon for being so engaged with the community. I really respect you for it. I also think you have a sharp looking product that seems very well implemented. I own 2x AHB2 for my main system, but your 3-channel purifi and ncx500 are top of my list for my HT expansion.

 

[Sokel]

Upon reviewing the measurements from @thin bLue, the primary discrepancy I've noted is the bandwidth he employs—60 kHz, in contrast to Amir and myself, who utilize 22.4kHz and 45kHz bandwidths, respectively. This choice could introduce a considerable amount of wideband noise into the measurements, which may not be reflective of an amplifier's performance within the audible frequency spectrum. It's worth noting that, like @thin bLue, I employed 100 points in the FFT for my analysis.

No,he states the bandwidth right next to the freqs at the board (says 10-20k for 1Khz),he has already answer to this.
And here's another,still different one from this review:

Purple (fixed) trace:

Still starts ballooing after 5 or so watts.
Clearly implementation or buffer or whatever makes a difference.
Good thing that all this happen at the abyss of under -100db THD+N.
It's only vice that drives this conversation.

(even in this same graph tighter terminals improved it by 20db when power started being serious! )

 

[Apollon Audio]

@Apollon Audio I just want to thank Apollon for being so engaged with the community. I really respect you for it. I also think you have a sharp looking product that seems very well implemented. I own 2x AHB2 for my main system, but your 3-channel purifi and ncx500 are top of my list for my HT expansion.

I deeply appreciate your kind words and commendation. Thank you.

 

[Apollon Audio]

No,he states the bandwidth right next to the freqs at the board (says 10-20k for 1Khz),he has already answer to this.
And here's another,still different one from this review:

Purple (fixed) trace:



View attachment 311568

Still starts ballooing after 5 or so watts.
Clearly implementation or buffer or whatever makes a difference.
Good thing that all this happen at the abyss of under -100db THD+N.
It's only vice that drives this conversation.

(even in this same graph tighter terminals improved it by 20db when power started being serious! )

In this review, the Hypex evaluation board was employed with the NCx500 module. It's important to understand that this evaluation board is designed primarily for evaluation purposes and may not be optimized for minimal distortion and doesn't have ideal audio signal path trace routing. In my opinion, this board may not fully represent the capabilities of the NCx500 module.

NC500 Evaluation board | H08U002306

www.hypex.nl

 

[mike70]

Why in the stereo amplifiers (not dual mono) you use the A700 power supply with Hypex and the A400 with Purifi?

The A400 is enough for the Purifi modules?
I think the Eval1 works in that way, but as you stated, that was an evaluation implementation.

 

[David_M]

The amplifier is equipped with dual 3000 watt power supplies, ensuring optimal performance when paired with 9 NCx500 modules. This configuration enables the delivery of a consistent 660 watts peak at 4 Ohms, even when all channels operate at their maximum capacity concurrently. There is minimal discernible variance between 120V and 240V mains input. Given a stable 120V supply, this amplifier can reliably produce 650 watts peak per channel at 120V.

What are the power ratings in 8, / 4, and 2 ohms All-Channels-Driven for this multichannel amplifier for 120V or 240V mains.?

 

[David_M]

@Apollon Audio, you have the patience of Job for sure!!!

Thank you for maintaining a good and professional attitude in this forum, performing all tests asked of you, despite the harsh accusatory tones of some of the questions asked in this forum. IMHO, they could have asked for the same info in a much polite way.

 

[echt]

While @restorer-john 's disdain for manufacturers who fail to provide FTC compliant continuous power ratings was provocative in tone and perhaps overly harsh in relation to Apollon in particular, I would not admonish him for disregarding Hypex’s power sweeps in their data sheets when ASR reviews critique manufacturers whose products run short of the amp module makers reference designs.

I agree with @amirm if you don’t have the actual sweeps and just have their self-reported FTC values, you are relying on the manufacturer’s honesty (and competence).

Perhaps ASR can request (not require) manufacturers provide their FTC power ratings with full test parameter specs (including the extra “test bandwith” parameter Amir highlighted) and the make and model of the analyzer used.

You get a “+” if you provide the FTC compliant data and “-“ if you do not. You get an extra “+” if you provide the sweeps with all relevant parameters (e.g. test bandwith,etc.). Likely those who get even a single "+" distinguish themselves from the pack.

If a manufacturer chose not to go full 20Hz – 20kHz might tell you what confidence they had in their engineering and or use case.

Kudos to Apollon for continuing to provide additional test data in a professional manner.

 

[KMO]

Why in the stereo amplifiers (not dual mono) you use the A700 power supply with Hypex and the A400 with Purifi?

The A400 is enough for the Purifi modules?

They're different voltage supplies, and they correspond to the voltages the amplifiers need. Purifi 1ET400A wants 65V, and the NCx500 wants 84V.

The Purifi could maybe do with a slightly higher voltage (the A400 is 63V), but it can't use the A700 supply, it's too high.