March Audio P122 Class D Amplifier Measurements

[tw99]

I am a SCM 40 user too.
I have seen 3rd party review/measurement said it is 84db, which not far from the spec 85db.

I wonder is Purifi 1ET400A good enough? or should I go with hypex 500 series

I'm using my SCM40s with a March P502. They go plenty loud enough.

 

[Sal1950]

I need 1200 into 8 please ATC state they can take 300, but then go on to say max SPL 112db. Which one would assume is at 1m. So taking that into account with 81db sens i think i could use 1200W... I dont believe it haha

Very likely their power limit of 300 is from a steady state signal, that would possibly fry a voice coil.
Max SPL rating for instantaneous-short term peaks.
Just a guess.

 

[dinglehoser]

Well, as most things in life its rarely that simple.

I have found that more power does tend to mean that things sound less strained and more dynamic when you do turn the wick up. Its not really about maximum SPL levels because you need to double power to increase by just 3dB. To put that into context generally people consider an increase of 10dB to sound twice as loud. For reference disconnect one of your speakers, that is now 3dB quieter.

Also speaker sensitivity has a *big* impact. As mentioned above double the power is required to increase SPL by 3dB. So an 85dB/w/m speaker needs twice the power to sound as loud as a 88dB/w/m speaker.

Another consideration is the parameters of the speaker load. If it has extreme phase angles the amplifier has to cope with dissipating (wasting) far more power than is being usefully used in the load.

This is just a syntactical sideshow, but wouldn't disconnecting a speaker from an amp actually result in a theoretical 6dB cut, at least for frequencies coherent as between the two speakers? Not only are you halving the driver count (-3dB), you're also taking half the power out of the equation (another -3dB).

 

[Leon37]

Hello everybody

3 questions about this amp and especially the NC122MP behavior:
- Do you have a buzz sound (50Hz) or other noise with this amp?
- What is the way which has the better SnR ( based on measurement: way 1 is better than way 2): way 1 = left or right?
- Sufficient to drive a center speaker ( BC acoustique AXIOS) with a impedance around 4 ohms?

Thank you

 

[March Audio]

Hello everybody

3 questions about this amp and especially the NC122MP behavior:
- Do you have a buzz sound (50Hz) or other noise with this amp?
- What is the way which has the better SnR ( based on measurement: way 1 is better than way 2): way 1 = left or right?
- Sufficient to drive a center speaker ( BC acoustique AXIOS) with a impedance around 4 ohms?

Thank you

Hi @Leon37

1. No 50hz buzz either through signal to speaker or mechanical (I. E. from transformer)
2. Can you explain what you mean a bit more, I don't really understand sorry.
3. Will drive the Axios easily. The Axios is high sensitivity at 91dB / 2.83 v / m. It will go high volume with low power.

Hope that helps

Alan

 

[Leon37]

Thanks Audio March for your quick answer

Sorry for the point 2 my english is not perfect ;-)

In the Amir measurement, the channel 1 seems better vs channel 2. I would like just to know if channel 1 = Left or right?
For this delta between the both channels, I know that is due to the hypex building itself ( I did not find first hypex data sheet which shows that channel 1 is better that N°2)

Regards

Leon37 (French guy who follows this forum with a huge attention !)

 

[Leon37]

Another short question: I have a Parasound HCA1205A and would like replace by 3 P122: do you have some experience on Parasound amplifier?

 

[Ajax]

I am a SCM 40 user too.
I have seen 3rd party review/measurement said it is 84db, which not far from the spec 85db.

I wonder is Purifi 1ET400A good enough? or should I go with hypex 500 series

I just came across this thread.

FYI I have the Nord MP NC500 (Hypex) amplifier, which is about 2 years old now, and it drives my ATC SCM 40 speakers without issue.

Good luck.

Ajax

 

[CDMC]

Thanks Audio March for your quick answer

Sorry for the point 2 my english is not perfect ;-)

In the Amir measurement, the channel 1 seems better vs channel 2. I would like just to know if channel 1 = Left or right?
For this delta between the both channels, I know that is due to the hypex building itself ( I did not find first hypex data sheet which shows that channel 1 is better that N°2)

Regards

Leon37 (French guy who follows this forum with a huge attention !)

The difference between channels is likely just module to module variation. It has no real effect and is inaudible.

 

[CDMC]

Another short question: I have a Parasound HCA1205A and would like replace by 3 P122: do you have some experience on Parasound amplifier?

It might help if you were more specific in your question. That said, the P252 is going to be more comparable as it has the same power, the P122 has less.

 

[nck045]

If I upgrade from the NC122MP to something better, say the Purifi 1ET400A or Benchmark AHB2, would there be an audible upgrade in sound quality? Only concerned about sound quality as I do not need extra power - my room is quite small and my speakers are 87db sensitivity.

 

[Sal1950]

If I upgrade from the NC122MP to something better, say the Purifi 1ET400A or Benchmark AHB2, would there be an audible upgrade in sound quality? Only concerned about sound quality as I do not need extra power - my room is quite small and my speakers are 87db sensitivity.

Personally I very highly doubt if you'll hear any difference in SQ.
In fact I'd be willing to bet a weeks pay you couldn't identify any difference when listening under a bias controlled DBT condition.

 

[AudioJester]

Personally I very highly doubt if you'll hear any difference in SQ.
In fact I'd be willing to bet a weeks pay you couldn't identify any difference when listening under a bias controlled DBT condition.

I would think so to, but didnt March do blind testing where eople could picm the difference? Bruno P also claims an audible difference?

 

[Sal1950]

I would think so to, but didnt March do blind testing where eople could picm the difference? Bruno P also claims an audible difference?

With all do respect to both, what would you expect from them?

 

[AudioJester]

With all do respect to both, what would you expect from them?

Your point is understood.

 

[archerious]

Hmm this P122 or NC252MP?

 

[Jefrpol]

Can this amp be connected to a sub via a high level input?

 

[ririt]

Can this amp be connected to a sub via a high level input?

it seems. Please look at https://rel.net/how-to-connect-a-rel-to-a-class-d-amp/. Rel explain a way to do it with such amp.

 

[Music1969]

Amplifier Power Measurements
Let's start with 4 ohm:

Hi @March Audio

Can this power amp drive 4 ohm drivers?

Like air motion transformer types, that are mostly resistive, flat 4 ohms?

For 2 hours straight? Or would overheating due to heat produced at 4 ohms constant power be an issue?

 

[tmtomh]

Hi @March Audio

Can this power amp drive 4 ohm drivers?

Like air motion transformer types, that are mostly resistive, flat 4 ohms?

For 2 hours straight? Or would overheating due to heat produced at 4 ohms constant power be an issue?

He can answer more definitively and specifically, but Hypex (and Purifi) based Class D amps can all drive 4 ohm loads - they're designed for it. Of course they can't drive such loads beyond their maximum power, as per the measurements in Amir's write-up. But at normal and even somewhat louder-than normal listening levels, sure.