Apollon NCx500ST Stereo Amplifier Review

[Julf]

@Buckeye Amps
So one is as good as the other, probably except for small differences.

Audibly, they are exactly the same.

Could they remotely recall the sound of the Nad C399 I had?

They will accurately reproduce the input signal.

Paired with the Wiim Ultra and Monitor Audio Studio 89 speakers, might they be too powerful?

Just don't turn up the volume too much.

 

[Labjr]

A friend bought a Hypex NCX500 stereo amp and now wishes he had more power. I wonder if there will be a Purifi based stereo amp with more power near the same price range?

 

[Julf]

A friend bought a Purifi stereo amp and now wishes he had more power. I wonder if there will be a Purifi based stereo amp with more power near the same price range?

Really? How much power does he need?

 

[lordhumungous]

Really? How much power does he need?

He might have 50 db bookshelves. .

 

[Labjr]

Really? How much power does he need?

I meant too say Hypex NCX500 Stereo amp. Says it doesn't seem like 200W.

 

[lordhumungous]

I meant too say Hypex NCX500 Stereo amp. Says it doesn't seem like 200W.

I’m assuming he fiddled with the gain switches ?

 

[Labjr]

I’m assuming he fiddled with the gain switches ?

He said it sometimes goes into protection when it's cranked.

 

[Everett T]

A friend bought a Hypex NCX500 stereo amp and now wishes he had more power. I wonder if there will be a Purifi based stereo amp with more power near the same price range?

How did your friend determine he needed more power? This sounds exactly like non-scientific rubbish unless his speakers are ridiculously hard to drive in a massive room and even then doubtful.

 

[lordhumungous]

How did your friend determine he needed more power? This sounds exactly like non-scientific rubbish unless his speakers are ridiculously hard to drive in a massive room and even then doubtful.

But they are 35db sensitivity speakers !

 

[Everett T]

But they are 35db sensitivity speakers !

What speakers are they as that is insanely low?

 

[lordhumungous]

What speakers are they as that is insanely low?

Im just kidding ! lol . Probably 2ohm rated too !

 

[Everett T]

Im just kidding ! lol . Probably 2ohm rated too !

Ok, but still. What speakers are they as a 2ohm rating will not effect the Hypex modules like a traditional class A or AB amp.

 

[Everett T]

I guess he forgot to ask you first. You moron.

Aren't you just a peach. Have a blessed evening.

 

[EJ3]

Ok, but still. What speakers are they as a 2ohm rating will not effect the Hypex modules like a traditional class A or AB amp.

This is a Class G (a version of AB) amp (full disclosure: I have 6 of these). The final test in this YouTube video loads it down to a 2 ohm load to see what will happen.

I'm thinking that (at least this amp) doesn't do what you are making reference to about AB amps & 2 Ohm loads.
Please let me know if it is something else that you are talking about with involving a 2 Ohm load?
Thank you for your consideration.
EJ3

 

[Everett T]

This is a Class G (a version of AB) amp (full disclosure: I have 6 of these). The final test in this YouTube video loads it down to a 2 ohm load to see what will happen.

I'm thinking that (at least this amp) doesn't do what you are making reference to about AB amps & 2 Ohm loads.
Please let me know if it is something else that you are talking about with involving a 2 Ohm load?
Thank you for your consideration.
EJ3

I was speaking to the Hypex amps, the same comment would apply to the Purifi amps. What speakers are they, again?

 

[Alexx]

Perfect, thanks for the info.

So I'll have to be a little careful with the volume, or set the sensitivity to a medium setting.

In any case, is the acoustic output of these NCX500 modules superior to the NC502MP ones? (The are also cheaper.)

Thanks again.

 

[EJ3]

I was speaking to the Hypex amps, the same comment would apply to the Purifi amps. What speakers are they, again?

Since it seems to me (at least for my gear) 2 ohms is just fine.
As to what a friend of this fellow is having problems with, he apparently does not have enough actual information on the issue for any of us to be able to potentially help him with the problem. As to why he threw it out here, I guess that we will never know.

 

[pma]

Ok, but still. What speakers are they as a 2ohm rating will not effect the Hypex modules like a traditional class A or AB amp.

Are you saying that 2 ohm load would not affect the Hypex modules as much as in case of a "traditional" class AB amplifier? I really do not think so. I have tested for you, 2 amplifiers into 2.2 ohm load. My apologies I do not have exactly 2 ohm.

The amplifiers are my A250W - class AB and my NC252MP - class D. They both are rated 2 x 250W/4ohm and they both have almost same power into 4 ohm load. The result into 2.2 ohm load is bellow:

The class AB amp has THD = 0.1% at 326W. The class D amp has THD = 0.1% at 200W, however soon after that the protection shuts the class D amp down. So it is definitely not "less affected" by the 2 ohm load, the opposite is true.

 

[Apollon Audio]

Are you saying that 2 ohm load would not affect the Hypex modules as much as in case of a "traditional" class AB amplifier? I really do not think so. I have tested for you, 2 amplifiers into 2.2 ohm load. My apologies I do not have exactly 2 ohm.

The amplifiers are my A250W - class AB and my NC252MP - class D. They both are rated 2 x 250W/4ohm and they both have almost same power into 4 ohm load. The result into 2.2 ohm load is bellow:

View attachment 470460

The class AB amp has THD = 0.1% at 326W. The class D amp has THD = 0.1% at 200W, however soon after that the protection shuts the class D amp down. So it is definitely not "less affected" by the 2 ohm load, the opposite is true.

View attachment 470465 View attachment 470466

The NC252MP and other MP-series modules are great for cost-efficient designs, but they’re not in the same league as Hypex’s higher-end offerings (NCx500, NC1200, NC2K) when it comes to stability and performance at 2-ohm loads.

The key difference is in the power supply architecture. The MP series has an integrated SMPS that is designed with efficiency and compactness in mind. While perfectly adequate for 4–8 Ω loads, it has limited continuous current delivery and smaller bulk capacitance reserves. When you push them into 2 Ω territory, the supply rails can sag under heavy current draw, which in turn increases distortion and can trigger protection or current limiting. In real-world use, that means reduced output power and less control over difficult speakers.

The higher-end modules, on the other hand, are paired with dedicated external SMPS units that have much higher current reserves, larger energy storage, and better rail voltage stability. Combined with improved thermal management and output stage design, the NCx500/NC1200/NC2K platforms maintain linearity and low distortion even when driving 2-ohm or otherwise difficult loads.

So while the MP modules are ok value and competent in normal 4–8 Ω applications, if you’re planning to drive big, low-impedance floorstanders or professional speakers that dip well below 4 Ω, the high-end Hypex platforms are simply more robust and will outperform the MP line every time.

 

[mike70]

Why we talk about a technology based on only one sample case or implementation?

Hey, somebody died with electrical current, electricity is too much dangerous, please, we need to go back to candles.