Apollon Multichannel Power Amp – NCx500 vs Purifi 1ET6525SA for 7.2.4 System

[chezterarm]

Hi everyone! I'm currently deciding between two multichannel power amps from Apollon Audio:

• Apollon Hypex NCx500 (11 Channel)
• Apollon Purifi 1ET6525SA (11 Channel)

The price is essentially the same, and I'm torn between them. I’ve been researching for 3–4 days but would love your opinions. Movie-Focused Setup

My system setup (7.2.4):​

• Front L/R: KEF Q11 Meta (1 Pair)
• Center: KEF Q6 Meta
• Surround (Side): KEF Q8 Meta (2 pcs)
• Surround (Back): KEF Q4 Meta (2 pcs)
• Atmos (Ceiling): KEF Ci200RR-THX (4 pcs)
• Subwoofer: KEF Kube MIE15 (2 pcs)
• Processor / Preamp: Marantz AV10
• Power Amp: N/A yet (that’s why I’m here!)
  

• Room Size: 4m x 5.5m​

What I’m unsure about:​

• Should I choose NCx500 (more power, 137dB SNR) or Purifi 1ET6525SA (more refined, lower THD)?
• For op-amps:
  • Is OPA1656 good enough?
  • Or should I go for Sonic Imagery 994 or Sparkos Labs S2590 Pro?
• Or maybe... power amps are overkill and Marantz Cinema 40 or 30 could already be enough for this setup?

I'd greatly appreciate any advice, thoughts, or shared experiences — especially from anyone who has used either of these Apollon builds. Thanks in advance!

• And which Op-Amp should I choose between these 3 models?

OPA 1655 (Standard) for 11ch
Sonic Imagery 994 (+1100$) for 11ch
Sparkos Labs S2590 Pro (+2200$) for 11ch

OR​

AVR Marantz Cinema 40 or 30 could be enough for this setup?​

 

[Vincentponcet]

What means "more refined" ?
The purifi has less idle power (1.6w vs 5.3w), but bit less power (230/430/510W vs 380/700/700W).
On thd/imd front, that's very much same ballpark.

On the opa, amir made a comparison.

Discrete OpAmp Review: Sonic Imagery vs Sparkos

Recently I reviewed the Nord Three SE 1ET400A Dual Mono Stereo Amplifier. That unit came with the Sonic Imagery's 990ENH discrete operational amplifier ("opamp") in the buffer stage (pre-amplifier). The owner then ordered a set of Sparkos Pro SS2590 discrete opamps. This gave me a chance to...

www.audiosciencereview.com

Apollon showed measurements of stock vs op1656 vs sonic imagery opa

Apollon NCx500ST Stereo Amplifier Review

Would it make any sense to move from a good class A/B amp with similar power to this? I have the Parasound A21, and I don't think it does, but I'm curious to what others think and why? In most cases, no. Unless if you care about your electricity bill, and if your parasound has problems with heat.

audiosciencereview.com

 

[Matias]

Welcome to ASR. As far as power and low distortion they are so overkill that it is a tie. Same with opamps. I am not usually too fixated into idle losses of class D modules as some people here, but when we are talking about 11 channels in a chassis, then the Purifi 1ET6525SA (11 x 1,6W = 17,6W) has a considerable advantage over the Hypex NCx500 (11 x 5,3W = 58,3W), so that would be my choice.

 

[kyuu]

I would just advise you to pick what is more important to you: lower idle power or more peak power. The performance difference between the Hypex and the Purifi is pretty well into inaudible territory. The higher peak power might make a difference if you listen to highly dynamic music at rather elevated SPLs, but ultimately probably won't make a difference either IMO.

 

[chezterarm]

Welcome to ASR. As far as power and low distortion they are so overkill that it is a tie. Same with opamps. I am not usually too fixated into idle losses of class D modules as some people here, but when we are talking about 11 channels in a chassis, then the Purifi 1ET6525SA (11 x 1,6W = 17,6W) has a considerable advantage over the Hypex NCx500 (11 x 5,3W = 58,3W), so that would be my choice.

thank you sir. The distributor recommended that I use the NCx500 because my speaker system requires a lot of power. So now I can't make any decisions. I'll ask my friends for their opinions first.

 

[kyuu]

thank you sir. The distributor recommended that I use the NCx500 because my speaker system requires a lot of power. So now I can't make any decisions. I'll ask my friends for their opinions first.

Don't know what your distributor was talking about. Those KEFs have perfectly decent sensitivity and are not difficult loads.

 

[NTK]

thank you sir. The distributor recommended that I use the NCx500 because my speaker system requires a lot of power. So now I can't make any decisions. I'll ask my friends for their opinions first.

The surrounds and ceiling speakers, 8 out of the 11 speakers in your system, certainly don't need, and are too small to handle, a lot power.

 

[chezterarm]

The surrounds and ceiling speakers, 8 out of the 11 speakers in your system, certainly don't need, and are too small to handle, a lot power.

okay sir. i should select 1ET6525SA right?

 

[NTK]

okay sir. i should select 1ET6525SA right?

That would be my choice*. I'd prioritize on the lower heat generation, especially for such a high power density multichannel amplifier (11 × 350 W @ 4 Ω).

The 1ET6525A should be more than sufficient to provide ample SPL in your 4 m × 5.5 m room. I used the SPL calculator below: 86 dB / 1W sensitivity (= 89 dB @ 2.83 V, 4 Ω) for the Q11 Meta, amplifier power 350 W @ 4 Ω, 2 channels, 12 ft listening distance, near wall placement, and the SPL is 106 dB. Assuming a peak-to-average ratio (headroom) of 20 dB, it is sufficient for 86 dB average listening level, which is very (and unhealthily) loud.

Peak SPL Calculator

[Edit] Note:
* The 1ET6525A are overkill for the surrounds and ceiling speakers. But I'm not going to over-complicate things, since that probably would also mean another box.

 

[chezterarm]

In this case, should I separate the Power Amp into 2 units?
1st unit, 8 channels, is for Surround 4 + Atmos 4 speakers
2nd unit, 3 Channel, is for L C R speakers

Or is it not necessary to separate anything? Can combine POwer Amps?

And Apollon products, if they are Multichannel, the number of Power Supply is 2 sets, right?

 

[welwynnick]

Hi everyone! I'm currently deciding between two multichannel power amps from Apollon Audio:

• Apollon Hypex NCx500 (11 Channel)
• Apollon Purifi 1ET6525SA (11 Channel)

The price is essentially the same, and I'm torn between them. I’ve been researching for 3–4 days but would love your opinions. Movie-Focused Setup

I think you've come to the same conclusion as me about how to build a great immersive system.
Regarding the power amps, I don't think you can go wrong with either.
For a long time I've thought an Apollon NCx500 is the answer to every amp question, and now there's a great alternative.
Personally I think the 1ET6525 is an under-rated hero. The 9040 gets the limelight, but the 6525 is virtually as good, just less powerful.
Firstly, I would check the power supply configuration. Apollon say one or two SMPS3000A depending on the configuration, and I guess it's two for an 11 channel amp, but I would make sure with them that's the case for both the NCx500 & 6525. IF it happened to be two PSU for the former and one for the latter, I'd say go with the former, though I think that's unlikely. You can probably toss a coin and you'll never be unhappy either way.

Regarding the op-amps I would definitely stick to the stock 1656, for several reasons.
Firstly, you'll be unlikely to hear the difference.
Second, mass production parts are reliable.
Third, the upgrade is expensive.
Fourth, when you look very deeply at the information that premium op-amp manufacturers do publish, you'll see that despite the marketing bluster, they're actually no better than the best mass-market ones.
Fifth, Amir has repeatedly published tests showing the same thing.
Sixth, if you really want to improve your system, use a high quality headphone amp with high input impedance, low output impedance, moderate gain and line outputs. The best example is the Topping A70Pro, but cheaper ones are good too. That will allow you to use lower output level from the Marantz Av10 so it performs better, AND by-pass the amp's input buffer so that performs better, too. I analysed all this in excruciating detail in this thread.

Maybe consider the forthcoming Marantz AV20 if you're sure that you will stick to 7.2.4.

 

[NTK]

In this case, should I separate the Power Amp into 2 units?
1st unit, 8 channels, is for Surround 4 + Atmos 4 speakers
2nd unit, 3 Channel, is for L C R speakers

Or is it not necessary to separate anything? Can combine POwer Amps?

And Apollon products, if they are Multichannel, the number of Power Supply is 2 sets, right?

The downside to a 11-ch 1ET6525SA amplifier is cost. Having excess power, assuming you are sensible with it, is not a problem.
If you want to save some money, and keep to all Apollon, you can go with a 3-ch 1ET6525SA plus an 8-ch NCMP8200 (4 × Hypex NC252MP). The combination will sound no different from the 11-ch 1ET6525SA.

The Apollon 3 to 5 ch 1ET6525SA configuration has one single 3 kW power supply. One 3 kW PS is sufficient for 6 channels (500 W/ch) at full power.

 

[chezterarm]

OR​

AVR Marantz Cinema 40 or 30 could be enough for this setup?​

 

[welwynnick]

They would be OK but they wouldn't be as good

 

[NTK]

OR​

AVR Marantz Cinema 40 or 30 could be enough for this setup?​

Quite likely, at least for the Cinema 40, which Amir has tested. Amir found it to be quite competent.

Marantz Cinema 40 AVR Review

This is a review and detailed measurements of the Marantz Cinema 40 9.4 channel AV Receiver (AVR). It is on kind loan from a member and costs US $3,500. As is typical in this class, you get a very large box. At least the look is unique and to my liking. The port hole display while limiting...

www.audiosciencereview.com

 

[jhaider]

No offense, but the whole plan seems out of wack. Most glaringly, the electronics are wildly disproportionately expensive compared to the loudspeakers, and within the loudspeakers the heights are too expensive relative to the bed layer.

First, get a cheaper pre-pro, or an AVR. That one is stupid expensive and you’re not even using the capabilities that might justify the upcharge. IMO Monoprice HTP-1 is flatly superior at about half the cost (after DLBC upgrades to both, and not doing that at these price points is dumb). But D+M have more appropriate products for your desired setup as well.

Second, take the budget misallocated to electronics and apply it to better speakers. If you like KEF that means R not Q.

Third, consider 1 or 2 more subs, if you have space for them.

Fourth, if you need amps at all, think Hypex 252 or 502 not the fancier ones.

 

[chezterarm]

No offense, but the whole plan seems out of wack. Most glaringly, the electronics are wildly disproportionately expensive compared to the loudspeakers, and within the loudspeakers the heights are too expensive relative to the bed layer.

First, get a cheaper pre-pro, or an AVR. That one is stupid expensive and you’re not even using the capabilities that might justify the upcharge. IMO Monoprice HTP-1 is flatly superior at about half the cost (after DLBC upgrades to both, and not doing that at these price points is dumb). But D+M have more appropriate products for your desired setup as well.

Second, take the budget misallocated to electronics and apply it to better speakers. If you like KEF that means R not Q.

Third, consider 1 or 2 more subs, if you have space for them.

Fourth, if you need amps at all, think Hypex 252 or 502 not the fancier ones.

I will change to AV20 or AV30 which will be released soon.

 

[Billy Budapest]

Absolutely do not waste your money on silly boutique opamps. You’re paying a lot more money for the same or slightly worse performance (although inaudible).

 

[Mike_Trueman]

NCX500 is more power for the same price and you can not hear a difference with Purifi