Ncore - Dual Mono or Stereo?

[BaaM]

Hey guys

I'm going to get a ncore amp for my loudspeakers but I'm hesitating between two mono blocks and a stereo amp.

Here are the models :
- https://www.audiophonics.fr/en/powe...reo-amplifier-ncore-2x150w-8-ohm-p-14185.html
- 2* https://www.audiophonics.fr/en/powe...-mono-class-d-ncore-1x250w-4-ohm-p-12844.html


The stereo amp would be a little cheaper, so is there a real objective interest to go with the mono blocks and Its power supplies?
I've searched the forums quite a bit, but unfortunately, nothing conclusive, so I'm asking here.

Thank you very much in advance

 

[VintageFlanker]

Hello,

As some know, I owned a pair of PA-M250NC and sold these to @Aap op Sokken .

These are excellent amps for the price.

Still, on the other hand, the new 252MP (which didn't exist few days ago) is offering is a better value. Plus, these have XLR inputs, which is recommended by Hypex.

Both measure really good. The NC250MP is a touch better but the two should be audibly very similar if not identical.

I would go for the NC252MP .

 

[BaaM]

IKR. (Je t'ai PM sur TN)

Thank you for your reply, so having two power supplies cannot bring anything from an objective point of view, really? Even with loudspeakers?
I have read things about the power reserve but I don't know exactly if it is legit, or not...

As for the absence of the XLR, I plan to buy this kind of adapters if Id go with the mono amps : https://www.toutlehautparleur.com/s...k-6-35-mm-femelle-vers-xlr-male-3-points.html

 

[VintageFlanker]

IKR. (Je t'ai PM sur TN)

Pardon, j'ai vu ton MP et pas eu le Temps de répondre.

Thank you for your reply, so having two power supplies cannot bring anything from an objective point of view, really? Even with loudspeakers?
I have read things about the power reserve but I don't know exactly if it is legit, or not...

It could matter for mono modules like the NC400 where two modules will need two SMPS to go at their full power. But not in that case.
Just see both THD vs power graphs:

250MP:

252MP:

In both cases, the clipping starts around 200W (4ohms) and 100W (8ohms). The stereo module is not power-limited at all. Also, @March Audio tested this same module (and NC502MP), running at full power, during several minutes.

As for the absence of the XLR, I plan to buy this kind of adapters if Id go with the mono amps :

Still not balanced. Again, if you have XLR outputs, go for the NC252MP.

 

[Matias]

I would go dual mono for maximum channel separation peace of mind.

 

[VintageFlanker]

I would go dual mono for maximum channel separation peace of mind.

Hum. Still mostly related to a common belief.
See the NC252MP review:

Crosstalk performance was excellent:

Nothing to worry about.

 

[Matias]

Yes, well, -85 to -100dB crosstalk is still more than nothing at all from running physically separated monos. I would pay the price difference.

 

[Hipper]

I was told by Nord amps that as far as sound goes it makes no difference between two monos or one stereo amp.

If so you just have to consider your own practicalities. Do you want longer speaker cables and shorter interconnects (when using a stereo amp) or shorter speaker cables and longer interconnects (for the mono blocks). Also of course power sources as two mono blocks near the speakers will either have long power cables or need some plug socket nearby.

I'm no expert and it comes down to signal loss in the cables. Others can chime in whether this is significant or not.

 

[Aap op Sokken]

* Power is identical
* I wouldn't worry about -85dB crosstalk.
* Balanced input is only going to add something if you have a balanced source, and even then the effect is small if your cables aren't too long.
* You can place monoblocks closer to the speakers, but i don't see why you would.

So i don't see any real difference. I would pick the cheapest option!

 

[BaaM]

Thank you very much for your informative answers, guys.
So the most reasonable choice seems to go with the stereo amp, it's true that adding two XLR adapters intensifies the price difference.
For the DAC, I plan to buy a SMSL S8U which is balanced, so that's a plus too.

I would like to take this opportunity to ask you about the power of the amplifier.
I started to think about the 250 version because several people told me that it would be more than enough for my speakers, but I might as well check with you:
Here are my DIY speakers: https://en.toutlehautparleur.com/fl...s-kristel-with-cabinet-and-crossover-kit.html
I listen at a distance of 4 meters from my speakers.
Sensitivity: 95 dB
Permissible electric power : 350W
Minimum impedance: 3 Ohm

Do you think that could I benefit positively from a Ncore NC400 amp, or is it definitely overkill for my speakers?

Thanks again!

 

[Matias]

I was told by Nord amps that as far as sound goes it makes no difference between two monos or one stereo amp.

Depends what's inside the chassis.
If there are separate power supplies boards and separate power modules then sure, stereo is the same as 2 monos. But a single stereo board with shared power supply then this should have some crosstalk. Audible or not but definitely more than separates.

 

[VintageFlanker]

For the DAC, I plan to buy a SMSL S8U which is balanced, so that's a plus.

Also, a new version to come: SU-8S, with volume knob. But no release date yet. I would also consider the M500, already available.

Do you think that could I benefit positively from a Ncore NC400 amp, or is it definitely overkill for my speakers?

Yes, NC400 are slightly cleaner, distortion-wise... But in real environment, NC250MP and 252MP are audibly transparent enough. Plus, your speakers are 95db sensitive, so you don't need the NC400 extra power, IMHO.

 

[ofrappier]

Hi,

Can someone explain me, the XLR dBu Balanced output/input needed from a DAC to the NC252MP, at full power ?
6 dBu ?

But DAC balanced output are between 13 and 20 dBu ?

 

[March Audio]

2 v rms or basically any standard dac output will get them to full power.

 

[VintageFlanker]

Can someone explain me, the XLR dBu Balanced output/input needed from a DAC to the NC252MP, at full power ?
6 dBu ?

According to datasheet: 6.61dBu (1.66V).

But DAC balanced output are between 13 and 20 dBu ?

That is why you imperatively do need a DAC with variable output or a preamp.

 

[March Audio]

Or software controlled volume

 

[ofrappier]

but what's happen if i have 10 dBu or 13 dBu instead of 6 dBu (error volume) ?
(My MOTU 8A can Trim DAC output , -4dB to 20 dBu in settings), so i've to make an OSC variable -4 dBu to 8dBu ?)

OSC variable (In OSCULATOR SOFTWARE) for ESS9018, MOTU 8A 1/2 output :
/ext/ibank/0/ch/0/trim
/ext/ibank/0/ch/1/trim
(Value -24 to -12, to have -4 to 8 dBu)



Thanks

 

[BaaM]

Also, a new version to come: SU-8S, with volume knob. But no release date yet. I would also consider the M500, already available.

The flow of chinese novelties is going so fast, it's insane...
I can't wait more than two weeks, so I'm going to fall back on the old model, already obsolete, haha.
As long as I can control the volume with the remote control, I don't need a knob.

Yes, NC400 are slightly cleaner, distortion-wise... But in real environment, NC250MP and 252MP are audibly transparent enough. Plus, your speakers are 95db sensitive, so you don't need the NC400 extra power, IMHO.

Alright, perfect, will buy the AUDIOPHONICS MPA-S252NC then.

 

[VintageFlanker]

Or software controlled volume

Yep. I know your DAC1 and amp combo works that way. However, this is not a convenient usage in my book.

Using a fixed output only variable by software could cause injury to speakers if not carefully checked. Imagine some case where Windows volume comes back to maximum after reset, update or such. As far as I'm concerned, I much prefer to put my fingers on a volume knob than use a mice to set the volume.

 

[March Audio]

Yep. I know your DAC1 and amp combo works that way. However, this is not a convenient usage in my book.

Using a fixed output only variable by software could cause injury to speakers if not carefully checked. Imagine some case where Windows volume comes back to maximum after reset, update or such. As far as I'm concerned, I much prefer to put my fingers on a volume knob than use a mice to set the volume.

No more so than leaving an analogue volume turned up - I have certainly done this but I have never had runaway volumes or loud noises using Roon software volume.

This is entirely a set up issue. You dont have to have your device enabled for windows sound and run it in exclusive mode. As far as Im concerned I much prefer my volume control on the ipad/tablet that Im remotely operating the music selection from