Apollon NCx500ST Stereo Amplifier Review

[proux]

SO i think i am close to taking the plunge but this whole class D is new to me....

How do i decide whether to get the Purifi of Hypex?
If i get Purifi,which of the three should it be? and why is one so much more expensive- the 1ET7040SA, even though it has slightly less power?

I guess it's up to me whether to pay for the Lux case... probably not

but then maybe i could stretch to a dual mono, which in theory i guess gives better channel separation, but i could do with a small box instead

Too many choices...

The sources will be: Shanling ET3 CD transport / streamer > Audial DAC S5 and Project TT with Hana SL MC > MC Pro (classic audio)

Pre-amp will be Lab12 Pre1, to add a little tube magic for the first time, gain is 21 dB so will set a low gain on the Apollo.

This will go to XLR, but I will use the RCA for the pre-outs of my AVR for occasional surround,

Speakers are Sonus Faber Olympica I (standmounts),

• Frequency response: 40Hz-30kHz
• Sensitivity: 88dB SPL (2.83V/1m)
• Nominal Impedance: 4Ω
• Amplifier power handling: 50-250W

I also have a REL T5 connected high level by Speakon to bare wires to my current Moon amp speaker terminals, so presumably this should also work for the Apollo?

Sorry about all this, any and all suggestions welcome!

 

[NTK]

SO i think i am close to taking the plunge but this whole class D is new to me....

How do i decide whether to get the Purifi of Hypex?
If i get Purifi,which of the three should it be? and why is one so much more expensive- the 1ET7040SA, even though it has slightly less power?

I guess it's up to me whether to pay for the Lux case... probably not

but then maybe i could stretch to a dual mono, which in theory i guess gives better channel separation, but i could do with a small box instead

Too many choices...

The sources will be: Shanling ET3 CD transport / streamer > Audial DAC S5 and Project TT with Hana SL MC > MC Pro (classic audio)

Pre-amp will be Lab12 Pre1, to add a little tube magic for the first time, gain is 21 dB so will set a low gain on the Apollo.

This will go to XLR, but I will use the RCA for the pre-outs of my AVR for occasional surround,

Speakers are Sonus Faber Olympica I (standmounts),

• Frequency response: 40Hz-30kHz
• Sensitivity: 88dB SPL (2.83V/1m)
• Nominal Impedance: 4Ω
• Amplifier power handling: 50-250W

I also have a REL T5 connected high level by Speakon to bare wires to my current Moon amp speaker terminals, so presumably this should also work for the Apollo?

Sorry about all this, any and all suggestions welcome!

The amplifier modules you listed from Purifi and Hypex are all essentially perfect when operating within their output capacities, and you'll not be able to tell them apart in blind tests.

Manufacturers decide on their product pricing based on a multitude of reasons, and prices often do not correlate directly to manufacturing cost or performance. Purifi positions itself as more of a premium brand than Hypex, Their products do have better on paper performance. Any of the ones you listed will be a safe choice and should have sufficient power to drive a small stand mount 2-way speakers. If you really have no preference, then go for the NCx500 for more power and lower price.

You can't, however, connect your REL subwoofer to the NCx500 with the REL speaker level input method since the NCx500 speaker outputs are not ground referenced, You will need to use a proper stereo-to-mono summing adapter (DO NOT use a plain y-cable, it is for splitting signal, not summing, see Rane's Why not Wye? for details) to sum your pre-amp RCA outputs to feed your REL sub.

The Purifi 1ET7040SA, on the other hand, is OK as it has ground referenced speaker output, though Purifi recommends against it as it may interfere with the amplifier's feedback mechanism and potentially degrades the performance (which, IMHO, is not a serious concern).

 

[Julf]

Pre-amp will be Lab12 Pre1, to add a little tube magic for the first time, gain is 21 dB so will set a low gain on the Apollo.

The main reason for people to go for hypex or purifi is their transparency and accuracy, so they are a bit of an odd choice if you actually want the coloration and distortion of tubes.

 

[proux]

The main reason for people to go for hypex or purifi is their transparency and accuracy, so they are a bit of an odd choice if you actually want the coloration and distortion of tubes.

yes my logic is to keep
the sound of the preamp unaltered. still remain to be seen if it's a good idea or not. Size, weight, heat also matter

 

[Julf]

Size, weight, heat also matter

Yes, but doesn't a tube pre (with bulky tubes that dissipate a lot of power as heat) kind of defeat that idea? If you want the "warm" coloration and distortion, DSP would give you more flexibility.

 

[proux]

Yes, but doesn't a tube pre (with bulky tubes that dissipate a lot of power as heat) kind of defeat that idea? If you want the "warm" coloration and distortion, DSP would give you more flexibility.

you are probably right, but too late now, lab12 on the way, class D TBC... It is meant to have stunning soundstage, let's see

 

[Julf]

you are probably right, but too late now, lab12 on the way, class D TBC... It is meant to have stunning soundstage, let's see

Yes, tube (and other "audiophile" gear) often come with claims of un-measureable and mostly undefined characteristics

 

[proux]

Yes, tube (and other "audiophile" gear) often come with claims of un-measureable and mostly undefined characteristics

We shall see if Stereophile class A rating is worth much... but of course i could have confirmation bias and be happy

 

[proux]

The amplifier modules you listed from Purifi and Hypex are all essentially perfect when operating within their output capacities, and you'll not be able to tell them apart in blind tests.

Manufacturers decide on their product pricing based on a multitude of reasons, and prices often do not correlate directly to manufacturing cost or performance. Purifi positions itself as more of a premium brand than Hypex, Their products do have better on paper performance. Any of the ones you listed will be a safe choice and should have sufficient power to drive a small stand mount 2-way speakers. If you really have no preference, then go for the NCx500 for more power and lower price.

You can't, however, connect your REL subwoofer to the NCx500 with the REL speaker level input method since the NCx500 speaker outputs are not ground referenced, You will need to use a proper stereo-to-mono summing adapter (DO NOT use a plain y-cable, it is for splitting signal, not summing, see Rane's Why not Wye? for details) to sum your pre-amp RCA outputs to feed your REL sub.

The Purifi 1ET7040SA, on the other hand, is OK as it has ground referenced speaker output, though Purifi recommends against it as it may interfere with the amplifier's feedback mechanism and potentially degrades the performance (which, IMHO, is not a serious concern).

ok i think that makes me edge towards purifi, many thanks

 

[Julf]

We shall see if Stereophile class A rating is worth much... but of course i could have confirmation bias and be happy

I think we have seen what Stereophile rankings are worth.

 

[proux]

I think we have seen what Stereophile rankings are worth.

that's ominous!

 

[mike70]

that's ominous!

that's science ... but, think "you get what you paid" and in some years buy a more expensive tube preamp because it will be better.

And, never, never do a blind listening session ... You'll be poorer, but happy.

 

[Julf]

that's ominous!

Reality often is.

 

[proux]

that's science ... but, think "you get what you paid" and in some years buy a more expensive tube preamp because it will be better.

And, never, never do a blind listening session ... You'll be poorer, but happy.

i largely agree... but blind listening sessions (where my friend who is a trained pianist, but not hifi obsessed, was the blinded judge) made me decide on DAC- Audial S5 edged out Denafrips Pontus II, hence selling the latter

 

[Julf]

i largely agree... but blind listening sessions (where my friend who is a trained pianist, but not hifi obsessed, was the blinded judge) made me decide on DAC- Audial S5 edged out Denafrips Pontus II, hence selling the latter

Just make sure it is double blind - single blind tests are pretty much useless.

 

[JeremyFife]

you are probably right, but too late now, lab12 on the way, class D TBC... It is meant to have stunning soundstage, let's see

Enjoy your new gear, that's always a fun day

Just to temper some expectations though ... soundstage can't come from the electronics (recording and speaker/room interaction). Does not mean you won't enjoy the sound though.

 

[mike70]

i largely agree... but blind listening sessions (where my friend who is a trained pianist, but not hifi obsessed, was the blinded judge) made me decide on DAC- Audial S5 edged out Denafrips Pontus II, hence selling the latter

when we talk about blind listening, we mean ... a proper blind listening.
in this site you have a good amount of information about it, like gain levelled devices, etc.
there're other people with public tests about it, like this: https://archimago.blogspot.com/2024/04/2024-high-end-dac-blind-listening-survey.html

is very, very (i said very already?) difficult to perceive differences between 2 transparent DACs in an ABX test with levelled gains. That means, surely bats will have differences, but humans ... unlikely. And the situation get worst with age, over 50 if you listen to 15khz you need to celebrate.

 

[proux]

yes maybe i shouldn't have opened that can of worms on an unrelated thread, sorry
the gain was not levelled by measurements, so this could of course be all there is to it

 

[mike70]

yes maybe i shouldn't have opened that can of worms on an unrelated thread, sorry
the gain was not levelled by measurements, so this could of course be all there is to it

well, isn't a can of worms, is simply a honest discussion.
the spirit in this forum is about the objectivity side of the audio reproduction, so, your posts will be discussed inevitably.

if you think the subjective side is the right position, there're many more forums for that (i mean, you don't need to "suffer" or feel like a "can of worms")

 

[SorenTyson]

Just make sure it is double blind - single blind tests are pretty much useless.

As in both eyes closed and not just one?