Class D

[Vincent Kars]

Yeah! I'm looking forward to getting samples to update my amps.

It is on sale now: http://www.hypex.nl/index.php?option=com_content&view=article&id=100&Itemid=102
https://www.hypexshop.com/

 

[garylkoh]

It is on sale now: http://www.hypex.nl/index.php?option=com_content&view=article&id=100&Itemid=102
https://www.hypexshop.com/

Unfortunately, they are sold out and have been since the announcement. Jan-Peter is scheduled to visit at CES, I'll find out from him what's the story behind this - but the latest batch of UcD modules they delivered are laid out different from the previous batches, and look like they have different components. The NCore technology is supposed to cascade down through all their modules, and over the past 3 years since I've been using the Hypex modules, most of the batches delivered have been slightly different from the older ones.

From the first ones to the latest ones, there has been a slight improvement in SQ, but it's not night and day.

 

[Vincent Kars]

Had an improvement in SQ when upgrading the voltage regulators to HxR12.

 

[garylkoh]

Had an improvement in SQ when upgrading the voltage regulators to HxR12.

Yes, I've heard that many times. It's a worthwhile upgrade if you are building DIY using the UcD modules.

 

[Ki Choi]

Have you heard 250ASX2 ICEpower® Module based D amps?

A friend showed me the NC400 based Class D amps last night he is very high on... It looked interesting but haven't heard them yet.

Another friend's company in Korea makes above B&O ICEpower based class D amps:

http://www.aprilmusic.com/eng/main/sub02_04_04.html

It was their main demo amps with Wilson Sashas and DP1 DAC/Preamp.

I have a pair and they do sound amazing for their size and money... It's seems there's a bright future for these Class D amps.

 

[Husk]

Ki, Are you replacing your 9008's with these?

 

[Kal Rubinson]

Another friend's company in Korea makes above B&O ICEpower based class D amps:

http://www.aprilmusic.com/eng/main/sub02_04_04.html

It was their main demo amps with Wilson Sashas and DP1 DAC/Preamp.

One of the very best sounds at CES, imho.

 

[Vincent Kars]

6Moons about the nCore: http://www.6moons.com/industryfeatures/ncore/1.html

 

[Vincent Kars]

Bruno and Jan-Peter starts a new company: http://www.mola-mola.nl/

 

[amirm]

Interesting comments in their press release:

The Mola-Mola preamplifier is a conventional looking unit with five inputs, all of which are,
unconventionally, switchable between balanced and unbalanced operation. The gain stage is
said to have “completely unmeasurable” distortion, in spite of being potentiometer based.
Inside there is ample room for option boards such as an MC/MM stage or a DAC. The DAC’s
outstanding feature is a DSP-controlled crystal oscillator which locks instantly to new sources
but whose jitter rejection continually improves until after a few minutes the oscillator
essentially runs free. The mono power amplifier is, of course, based on Putzeys’ own 1200W
Ncore circuit which is rapidly garnering a reputation for itself.

All three Mola-Mola products express Putzeys’ idiosyncratic brand of audio objectivism: “We
all accept that bad measurements don’t necessarily mean that an amp or converter sounds
unpleasant. But the usual conclusion that good figures therefore don’t mean anything either,
is illogical. No serious audiophile is merely looking for a pleasant sound. It has to bring us
closer to the original.” This doesn’t quite mean he aligns himself with the skeptical camp
though: “By implying that distortion, jitter and other errors only become audible at some
impossibly high level, they have helped stoke the polarisation. That way the tools to make
audible errors completely negligible are left unused by either side. By subjectivists because
they don’t believe the goal is valid, by skeptics because they don’t believe they’re necessary. I
can assure you they are. Every time I’ve heard an amplifier step aside for the music, its
measured performance was impeccable.”

“People are genuinely moved when they listen to these products,” comments Van
Amerongen, “One said that the way the music touched his heart was proof positive that the
amplifier hadn’t touched the music. That’s pretty much the essence, isn’t it?

Don't quite follow the middle statement regarding objectivists/subjectivists .

 

[Vincent Kars]

Sounds a bit like a press release to me.

But I like the observation that although the arguments differ, the objectivist and subjectivist come to the same conclusion, a better specked newer model won’t sound better.

 

[kevinh]

The people over at DIY audio who have put together the NCore kits are uniformly happy so far.

They have replaced some pretty good amps with the NCore.

 

[amirm]

Hi Kevin. Thanks for the feedback. Has anyone done any measurements? I am especially interested in frequency response with different loads to see level of ringing/load sensitivity.

 

[kevinh]

Hi Kevin. Thanks for the feedback. Has anyone done any measurements? I am especially interested in frequency response with different loads to see level of ringing/load sensitivity.

The thread on the ncore is in the 4,000 post area now. IIRC people that have measures the unti have verified Hypex's claim. There are some measurements on their website.


If you go to pg 7 on the datasheet they have the graphs you are looking for:

http://www.hypex.nl/docs/NC400_datasheet.pdf


This DIY module is 200W/8ohms, 400/4ohms, 580/2ohms. This is with theri 600W PS. THe Cost for 2 ps and 2 mono amps ~1,200 USD.

The OEM Module is going to be higher power about 400W/ohms, with similar low impedance drive capability.

BTW outting the kit together is just hooking up a few wires and putting it in a chassis. Very simple.

The thread @ Diyaudio is here: http://www.diyaudio.com/forums/vendors-bazaar/190434-hypex-ncore.html



Around post #2,000 is where users have built amps and give their listening impressions and comparisons to other amps.

 

[fas42]

I might just throw in that the output impedance is 0.0025 ohms at 20kHz, and better at lower freq's, according to the spec's. Assuming they can measure reasonably well, this means any normal speaker load should have zero audible impact on the sound.

Frank

 

[kevinh]

yep Frank. Just imagine, once the signal is A/D converted at the mic, its digital all the way through until the output filter in the power amp. You are not going to have much to talk about concerning the amp/speaker interface if you use this baby. We truly are at the digital crossroads. But many audiphiles prefer their distortions...


Tom

Tom this unit uses an analog input with a discrete driver amp for the Class D output stage, this is different than the Tact for example.

They recommend a balanced signal from the Pre Amp or Dac for best results.

 

[fas42]

Sure miss those clipping indicators from the old days.

Tom

Do you want to know something scary, Tom? The digital soundtracks are full of clipping waveforms: the source has already been slightly mangled, when you first get it in the door!

So many of the tracks I've looked at lately have been "contaminated": the recording engineers are obviously pushed from above, or feel that they have to push the "energy" just that little bit, for other reasons.

Why I particularly say that, is after having looked at the Duende track, from the Black Light Syndrome album. This is supposedly demo quality, but it's riddled with clipping points ...

Frank

 

[amirm]

If you go to pg 7 on the datasheet they have the graphs you are looking for:

http://www.hypex.nl/docs/NC400_datasheet.pdf

Thanks. That is the right measurement but unfortunately it appears to use resistive loads. I love to see real speaker/simulated load like stereophile uses. Here is an example NAD M2 amplifier: http://www.stereophile.com/content/nad-m2-direct-digital-integrated-amplifier-measurements

The ringing is caused by too low of a switching rate forcing the filter to be close to the audible band. Same problem we have with DACs except that we now have much higher power requirement and unknown speaker/wire load.

 

[fas42]

Thanks. That is the right measurement but unfortunately it appears to use resistive loads. I love to see real speaker/simulated load like stereophile uses. Here is an example NAD M2 amplifier: http://www.stereophile.com/content/nad-m2-direct-digital-integrated-amplifier-measurements

The ringing is caused by too low of a switching rate forcing the filter to be close to the audible band. Same problem we have with DACs except that we now have much higher power requirement and unknown speaker/wire load.

Though reading that link, the measured output impedance of the NAD at 20kHz was over 1 ohm, which is pretty dreadful -- no wonder the FRs are all over the place. The nCore module is nearly 1,000 times better in performance in this key area.

Frank

 

[steve williams]

Why I particularly say that, is after having looked at the Duende track, from the Black Light Syndrome album. This is supposedly demo quality, but it's riddled with clipping points ...

I have never heard clipping on my amps with this track and I listen with a 32 wpc amp