SQ and reliability of NC502MP VS ICE1200AS2

[analogguy]

I’ve got NC400 based amp with SMPS 1200A400 PSU which I've assembled 8 years ago. I have no complaints about SQ but the built quality of SMPS is questionable. Mine started failing a year ago. I think they use cheap caps because the failure mode is longer delay which is typically associated with failing caps. A friend of mine built his NC400 in 2019 and his SMPS1200A400 died in 2023 and he ended up building linear PSU. I was also reading about this issue on DIY audio so it looks like it’s a common problem. I can’t find info about caps values in SMPS and don’t really have time at the moment to fiddle with them.

I’m thinking about either buying NC502MP based amp or ICE1200AS2 module. I’m planning to use them to run my stereo until I fix SMPS and then will repurpose them to run my DIY Ripols which are based on 2X 8 ohm 12” Dayton woofers and miniDSP. Ideally, I prefer an universal amp so when I need it I could use it as the main amp. I’ve never heard 1200AS2 but from what I was reading the module sounds a bit dull and muddy on the top and it require good buffers to sing but I think this view my came from the camp that also believes in different sound of cables, caps and so on so maybe it is just an audiofool talks.

Both SQ and reliability ( I expect electronics to last at least 25 years) are equally important to me and therefore I’ve got 2 questions: 1.Does anybody have compared NC400 Vs NC500MP ( I know about the spec but I don’t really care as I don’t possess super human hearing capabilities anyway) and ICE1200AS vs NC400. 2. Does anybody have any info about reliability of 1200AS and NC500MP. I would love to see the accelerated aging test results.

 

[delta76]

You can be sure they are not particularly more reliable or less reliable than other amps. Both exist for a long time and there is no wide reported issue with them, so the best conclusion you can come up with is that they have the normal failure rate (1-5%) in their first two years.
if anything both can be fixed by a competent audio repair shop, so I would go ahead and buy either of them from a reputable shop with proven track record of service

 

[Waxx]

NCore in general is reliable, more reliable than most. But you always got hte bad monday builds also. But a s said, there are no widespread reliability issues reported while these amps exist over 20 years now. I've build NC400's in 2014 and they are still in daily use since then (by someone else) without any issue. I myself use NC122MP based amps now without issues also.

 

[Matias]

Welcome to ASR. First I would consider fixing or even changing the SMPS instead of changing the amps themselves. Maybe SMPS from MicroAudio?

MicroAudio – SMPS for audio applications

micro-audio.com

As for reliability, 1200AS had reports of humming from the modules. And measurements wise it is good but NCore is better.

 

[analogguy]

Welcome to ASR. First I would consider fixing or even changing the SMPS instead of changing the amps themselves. Maybe SMPS from MicroAudio?

MicroAudio – SMPS for audio applications

micro-audio.com

As for reliability, 1200AS had reports of humming from the modules. And measurements wise it is good but NCore is better.

Thank you.
Somebody on DIY audio mentioned MicroAudio and I did check them but I was looking for SMPS with driver voltage 16V becaues I forgot that NC400 takes over when Vdr<16V so after your suggestion I looked it up again and I can use SMPS1K-PFC.

​

 

[Matias]

@MicroAudio can suggest which SMPS would be ideal for powering the NC400.

 

[ISchmidt]

This power supply seems to be what you are looking for: https://www.boomaudio.de/hypex-smps1200a400-netzteil

 

[analogguy]

This power supply seems to be what you are looking for: https://www.boomaudio.de/hypex-smps1200a400-netzteil

They also have them now in stock in Hypex DIY Audio store.

Welcome to ASR. First I would consider fixing or even changing the SMPS instead of changing the amps themselves. Maybe SMPS from MicroAudio?

MicroAudio – SMPS for audio applications

micro-audio.com

As for reliability, 1200AS had reports of humming from the modules. And measurements wise it is good but NCore is better.

Do you know if humming just HF noise coming from power supply transformers or its LF noise in audio chain? From my experience all switching power supplies make buzzing noise.

 

[MicroAudio]

@MicroAudio can suggest which SMPS would be ideal for powering the NC400.

SMPS1K-SN.

But it cannot deliver 16V on VDR, only the standard 15V.

Thanks

 

[Waxx]

The Hypex SMPS1200A400 is hard to beat. It's one of the best SMPS's arround, and in OEM form used in other high quality audio products also. Purifi does not makes their own psu, they recommend Hypex SMPS's for their amp boards as they were (at least in early form) designed by Bruno Putzeys himself when he was still working there.

It's the one i used in the Hypex build (2xNC400 modules) i did long ago (for someone else). The owner tried a regulated linear psu that should be good, but switched back to the smps that was better and lower noise. Class D, and certainly Hypex or Purifi boards just work better with SMPS as they were build with that PSU type in mind.

And no, not all swithcing psu's make no noise, only the not so good ones do. Tests of class D amps (almost all with smps) here should show you that noise if there was any, but what there is is so low that it's below our hearing treshhold.

 

[Sokel]

Do you know if humming just HF noise coming from power supply transformers or its LF noise in audio chain? From my experience all switching power supplies make buzzing noise.

No noise in the audio signal,it's silent there.
The low buzz some had is mechanical or something.

I have two of them 4 years now,they had a very low buzz (ear next to module) for about 2-3 days and from them on they are dead silent.,I have them on 24/7 with their (on module) auto on/off enabled.
Make sure you get them from official sellers,there's lots of probably factory rejected or fakes out there if you decide for them eventually.

 

[analogguy]

No noise in the audio signal,it's silent there.
The low buzz some had is mechanical or something.

I have two of them 4 years now,they had a very low buzz (ear next to module) for about 2-3 days and from them on they are dead silent.,I have them on 24/7 with their (on module) auto on/off enabled.
Make sure you get them from official sellers,there's lots of probably factory rejected or fakes out there if you decide for them eventually.

Thank you. From my experience all SMPSs produce very low level mechanical noise. If I buy 1200AS@ I will get it from parts express. I'm tempted as it takes one evening to cut the metal and to solder connectors and I'm pretty sure I can sell the amp at cost if for some reason I don’t like it.

 

[Sokel]

Thank you. From my experience all SMPSs produce very low level mechanical noise. If I buy 1200AS@ I will get it from parts express. I'm tempted as it takes one evening to cut the metal and to solder connectors and I'm pretty sure I can sell the amp at cost if for some reason I don’t like it.

I bet you will like it.Make sure you'll read the PDF,you may want to include some of the gazillion of features it has on board (even analog meters for voltage and amperage) .
Ask me anything if you're in doubt when building it.

 

[Guddu]

Does this 1200AS contain the new conductor?

 

[Sokel]

Does this 1200AS contain the new conductor?

No,it's still the Edge version as far as I know.
What's good about it is the ability to hook couple of more channels on the fly,like a 300 or 400a2,it has everything on board ready.

At my configuration I use 2 x1200as2 as mono and 2x300a2 each hooked to each 1200as2.
(it can be 8 channels this way but it can also be used as monos or the 300/400a2 at BTL configuration)

 

[analogguy]

I bet you will like it.Make sure you'll read the PDF,you may want to include some of the gazillion of features it has on board (even analog meters for voltage and amperage) .
Ask me anything if you're in doubt when building it.

I alredy love them for 1)cost2)power and 3)plug and play solution. I need amps for my subs anyway. As a sub option I'm planning to drive them with balancedminiDSP that presumably can output up to 4V. As a stereo amp I will drive it from my Octo Reserach DAC8 that can output 4V too. My understanding is that 1200AS/2 can take up to 8V, menaing that I need a buffer to get rated power.

 

[analogguy]

No,it's still the Edge version as far as I know.
What's good about it is the ability to hook couple of more channels on the fly,like a 300 or 400a2,it has everything on board ready.

At my configuration I use 2 x1200as2 as mono and 2x300a2 each hooked to each 1200as2.
(it can be 8 channels this way but it can also be used as monos or the 300/400a2 at BTL configuration)

How much power do you get from bridged 1200AS2? How do you cool them heatsink or fan?

 

[analogguy]

SMPS1K-SN.

But it cannot deliver 16V on VDR, only the standard 15V.

Thanks

It looks like I finally got in the right forum.
what is the difference between 1K-SN and 1K-PFC? Unless I'm missing something NC400 module can take over when Vdr< 15V. I clearly remember reading it when I was buying them as I was considering building linear PSU.

The Hypex SMPS1200A400 is hard to beat. It's one of the best SMPS's arround, and in OEM form used in other high quality audio products also. Purifi does not makes their own psu, they recommend Hypex SMPS's for their amp boards as they were (at least in early form) designed by Bruno Putzeys himself when he was still working there.

It's the one i used in the Hypex build (2xNC400 modules) i did long ago (for someone else). The owner tried a regulated linear psu that should be good, but switched back to the smps that was better and lower noise. Class D, and certainly Hypex or Purifi boards just work better with SMPS as they were build with that PSU type in mind.

And no, not all swithcing psu's make no noise, only the not so good ones do. Tests of class D amps (almost all with smps) here should show you that noise if there was any, but what there is is so low that it's below our hearing treshhold.

I can certainly hear buzzing noize from my SMPS1200A400 and I've heard it from my friend's SMPS. It is not loud but I can heat it from 0.5m or so if I dont have a lead on the amp. I've used a bunch of indutrial SMPSs, all Chiense, and I dont think that I had one that was complitly silent.
My understanding 1200A400 does not provide enough power for Purify boards to reach max rated power at least for 1ET 400A that I was considering and it was the primary reason why I've abandoned the idea.

 

[Sokel]

How much power do you get from bridged 1200AS2? How do you cool them heatsink or fan?

Not bridged,you can't bridge 1200as2 only the 300/400a2.
You can use it in mono though,actual power this way is about 600-700W/4 Ohm and you can see 1kW burst.
Here is a test another member did:

Power amps: continuous output power measurements

Are you measuring built in sub amps or using some sort of external amp for passive sub use? Mostly I wouldn't worry about an amp suited to the powered sub, but would worry more about if you're trying something with a "passive" sub and another amp....

www.audiosciencereview.com

I have them on heatshinks.

 

[Scrivs]

As another datapoint, similar to the OP. I acquired an NC252MP module, soldered up a few connections, and put it in a commercially available "enclosure." I've done the same with four separate Icepower 200ASC modules, similar cases, pin one problem dealt with.

The Icepower boards are still going strong seven years later. They haven't missed a beat and are more than up to the task PC>ADI-2 DAC>200ASC/200AC>Kef R5

The Hypex module has failed at right around the 5 year mark-- In my particular case, the aluminum heatsink that the output devices are attached to have warped the PCB over time, I haven't had time to perform a necropsy yet (will try to fix when I find some time). At a quick glance however, the solder joints on the pair of mosfets on the bottomof the board (below the stby xfmr) are wasted. One of the mosfets had two legs that had lifted due to the mechanical stress of the oem heatsinking solution (IMVHO).

Also on the top of the board (between the bulk caps and stby xfmr) are two components labeled G1 and G2. Anyone able to help a brotha out?