SQ and reliability of NC502MP VS ICE1200AS2

[Scrivs]

As for sound quality, the NC252MP's extra power (50WPC continuous vs the 200ASC's 40WPC) was the only differentiator between the Hypex/Icepower. At normal listening levels, the are indistinguishable from one another.

 

[Sokel]

As for sound quality, the NC252MP's extra power (50WPC continuous vs the 200ASC's 40WPC) was the only differentiator between the Hypex/Icepower. At normal listening levels, the are indistinguishable from one another.

Same with Purifi 1ET400A,other than the power we could not tell it apart from a 1200as2.
When things went hard 1200as2 had the advantage but other than that nothing to stick out or missing (that with ML ESL's )

 

[analogguy]

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?

5 year period is seems to be the breaking point for Hypex. The one that my friend had died after 5 and mine started showing a problem after 6 years but I have BAT VK 55 that I use quite often so mine actual usage was less than 4. I did find time to fix my SMPC1200A400 supply. As I expected the problem was caps with high ESR so my Hypex is alive and well but I would not say that mine was one off. There is at list a dozen of people on the net that faced similar problem with the power supply so the built quality is definitely not the best and I don't really care who designed them.

Over my 30+ year audiophile career I've owned more than a dozen of amps and I think the majority of US made amps lasted more than 20 years. I still have fully functional 30+ year old Audible Illusions pre and 20+ year old BATVK3i and we are talking tubes which are inherently less reliable. When it comes to Japanese electronics it is another story. I have unreasonably large collection of vintage top of the line Japanese turntables and some of them are close to 50 years old and they are still fully functional.

 

[analogguy]

Same with Purifi 1ET400A,other than the power we could not tell it apart from a 1200as2.
When things went hard 1200as2 had the advantage but other than that nothing to stick out or missing (that with ML ESL's )

I bought 1200AS2 and the case so hopefully will have up and running in a week or so. I've started seriously considering 1ET400A after reading that according to Purify Hypex exibits some digital distortion and 1E400A has none. After reading your post I think I will pass.

 

[Lars Risbo]

I bought 1200AS2 and the case so hopefully will have up and running in a week or so. I've started seriously considering 1ET400A after reading that according to Purify Hypex exibits some digital distortion and 1E400A has none. After reading your post I think I will pass.

all class D amps with output inductors using ferro-magnetic cores (ferrite) exhibit magnetic hysteresis distortion. this includes purifi and hypex as well as ICE. What matters is how much is left after the feedback loop suppresses it. This is where the ET amps boasts the highest loop gains which takes the hysteresis distortion down the furthest.

 

[analogguy]

all class D amps with output inductors using ferro-magnetic cores (ferrite) exhibit magnetic hysteresis distortion. this includes purifi and hypex as well as ICE. What matters is how much is left after the feedback loop suppresses it. This is where the ET amps boasts the highest loop gains which takes the hysteresis distortion down the furthest.

I'm familiar with the concept of magnetic hysteresis deistortion in MC cartridges but I when I compared coreless and cored MCs I could not hear any difference so I wander how audible is this?
I wander why they don't use coreless inductors in class D?
By the way here is the link to detailed explanation of the core distortion https://purifi-audio.com/blog/tech-notes-1/this-thing-we-have-about-hysteresis-distortion-3

 

[Lars Risbo]

air cored inductors for class D are bulky and have more power losses typically. Also, the leakage field is huge. We used copper foil air cored inductors in the TacT Millennium amp.

Cheers

Lars (Purifi and Toccata)

 

[analogguy]

air cored inductors for class D are bulky and have more power losses typically. Also, the leakage field is huge. We used copper foil air cored inductors in the TacT Millennium amp.

Cheers

Lars (Purifi and Toccata)

I was reding somewhere that according to Bruno the hysteresis distortion causes grainy highs. My only experience with D class and Hypex is NC400 and I was really working hard to find the fault with the amp when I first put it together and I failed. In my experience the common weaknesses of the digital source is the reproduction of certain piano keys and cymbals and sometimes glare around voices ( which is likely more attributed to the compression during mastering than the technology itself).
Could you tell me what instruments and in what frequency range are affected by the hysteresis distortion?

Cheers, Alex

 

[andrewjohn007]

Regarding the 1200AS2 and driving a 300A2, I received this bit of technical insight from Profusion PLC:

"The 300A2 is designed to be powered as a hanger module by the 1200AS2. What the datasheet does NOT tell is that the default delivered version of the 1200AS2 has got a too high hanger voltage (Typ. +-63V) for the 300A2. If customers want to drive a 300A2 (which the datasheet says it can) they must order the +-57V hanger voltage version of the 1200AS2. Unfortunately, the datasheet does not say anything about this. The 1200AS2´s we´ve got in stock are the default 63V versions so they will not work with the 300A2"

You have no idea how hard it was for me to uncover this bit of critical information as back in 2022 I had purchased a 1200AS2 and had two 300A2s that I wanted to use with it. That being the case, I've been using the 1200AS2 to this day (sans any hangers) without issue whatsoever. It's a fantastic amp and I drive it hard at times. For what it's worth, I have it mounted alone in a case that is cooled with two 40mm Noctura fans (inflow/outflow) thereby keeping the internal temps well below the danger level.

 

[Sokel]

Regarding the 1200AS2 and driving a 300A2, I received this bit of technical insight from Profusion PLC:

"The 300A2 is designed to be powered as a hanger module by the 1200AS2. What the datasheet does NOT tell is that the default delivered version of the 1200AS2 has got a too high hanger voltage (Typ. +-63V) for the 300A2. If customers want to drive a 300A2 (which the datasheet says it can) they must order the +-57V hanger voltage version of the 1200AS2. Unfortunately, the datasheet does not say anything about this. The 1200AS2´s we´ve got in stock are the default 63V versions so they will not work with the 300A2"

You have no idea how hard it was for me to uncover this bit of critical information as back in 2022 I had purchased a 1200AS2 and had two 300A2s that I wanted to use with it. That being the case, I've been using the 1200AS2 to this day (sans any hangers) without issue whatsoever. It's a fantastic amp and I drive it hard at times. For what it's worth, I have it mounted alone in a case that is cooled with two 40mm Noctura fans (inflow/outflow) thereby keeping the internal temps well below the danger level.

I had the same questions regarding the exact same conditions for my mono's (2 x 1200as2 and 2 x 300a2)
I asked Soundimports about it and they assured me that there is no problem so I took the gamble.

Measured at my set-up voltages are 62VDC and -62.2VDC.
I operate them like that give or take for about 4 years 24/7 but I do have them in well heat sinked enclosures.
300a2's at my active set-up (>250Hz) runs completely cold even at no humane SPL .
i200as2's on the other hand can run warm(42° C) even at idle and strangely run cooler as things go tough.

 

[andrewjohn007]

No kidding?!?! Thank you for sharing. Now you've got my wheels spinning as there are two brand new 300A2s sitting on the shelf staring at me. I'll let you know if I take the plunge.

 

[Sokel]

No kidding?!?! Thank you for sharing. Now you've got my wheels spinning as there are two brand new 300A2s sitting on the shelf staring at me. I'll let you know if I take the plunge.

You won't miss,I know.
I have tested all that in ways no system deserves, believe me.
(I'll PM you the mail as well)

 

[andrewjohn007]

Beautiful! Thank you so much!

 

[Sokel]

Beautiful! Thank you so much!

Take your time building them, double-triple check voltages, polarities, etc.
It needs 7 cables if I remember well (all included with the modules), 3 for the rails and 4 for the drive.
Not a bad Idea to connect some multicolor leds to show you lots of info too.

Happy built!