Hypex N core module

I will try and explain my experience. I was happy with my Theta Prometheus monoblocks. They are very good at bass frequencies along with a very wide soundstage. The upper end was smooth and non fatiguing. I had them when I was setup with a multichannel system. I must add that I am much happier with my D’Agostino Progression monoblocks and going back to stereo only. They are obviously much better in the midrange, and are more dynamic from top to bottom. They are smoother and more powerful than the Prometheus and have an high end with a more natural sounding reproduction overall in comparison in instrumental tone and vocals. Now when I listen to music, my senses are awakened and it seems my "foot tapping" on the floor is natural and instinctive. The amazing difference I have discovered is that when both amps were pushed with the same exact disc (Red Violin track 20), the Theta was slightly strained when pushed on this one track, and it's dynamic orchestral peaks. Of course with the D'Agostino Progressions that doesn’t happen. Each instrument can be clearly heard and effortlessly. I am waiting for someone to chime in on the price differences. You do get what you pay for in this instance. It just depends on how deep one's pockets are!

Hi bache,

     I wanted to elaborate a bit on hgeifman's post above just in case you might google his amps and get scared off by the msrp price of $16,500.
     The 6 Moons review on these class D mono-blocks that I read concluded that these may be the best amps you can buy regardless of type or price that they have ever reviewed.  This clearly positions them at the high end of the quality/performance continuum I discussed in my last post.

     Mola Mola is actually a company founded by the inventor of both UcD (universal class D) and Hypex-NCore technology, Bruno Putzeys, and Hypex founder Jan-Peter von Amerongen.  Hypex supplies their top of the line NC-1200 power modules and SMPS (Switch Mode Power Supplies)  NC-1200 power supplies to OEM  amp manufacturers such as Acoustic Imagery, Merrill Audio, Jeff Rowland, Bel Canto Design and Theta Digital for use in their high quality class D amps. 
     The Kaluga monos utilizes custom class D power modules designed by Bruno Putzeys that are not available to OEM competitors.
     Class D technology has also progressed to the point that Hypex modules now have serious competitors that some believe even outperform them such as the latest Ice UcD modules used in certain Red Dragon amps,  Abletec/Anaview modules used in certain D-Sonic amps and the Pascal modules used in certain Jeff Rowland and D-Sonic amps.  In addition, class D technology is continuing to be developed and other class D modules/amps may be available in the near future.  There are also Hypex NC-400 power module amps available from custom assemblers such as James Romeyn that approximate but don't match the performance of NC-1200 module amps.
     The good news being that there are significantly less expensive very good class D amps currently available that are positioned somewhat lower on the quality/performance continuum than the Mola Mola Kalugas and Merrill Audio Veritas amps but still provide very good performance.

Tim     
      

" @noble100 How inappropriate. In fact I’m not ignorant, I speak from fact and after ownership of several higher-level N-Core Class D amps within the past year. None came close to giving the musical pleasure and satisfaction of my current Class A/AB amps. You can grandstand and type away until your fingers are red but it won’t change my opinion."

Hi jaybe,
      I had no intention of offending you with my prior post.  I think it just strikes a nerve with me when I read comments that repeat that old refrain about class D amps being only good enough for subwoofers and not for reproducing the entire audio spectrum with high fidelity.  I consider that criticism valid for some earlier brands/models of class D amps but not valid at all for the class D amps I own as well as many other current brands/models.
      I agree that good sound is subjective and system matching is important for achieving the system sound you prefer in your system and room.  I also believe there may be poorly understood and unidentified sound artifacts with class D amplification that some are able to hear that others, like myself, are unable to detect.  At this point, it's hard to prove but still a possibility.
     I think it's important to tell you I was not calling you ignorant, I was careful to call your statement ignorant.  The difference?  I believe you're experienced in audio matters and capable of knowing whether you like the performance of a component or not but conveying that good quality class D amps are only useful as sub amps is not accurate anymore, at least not for all individuals.
     I also may not have been clear enough in my post that I was making comparisons between good quality class A/B amps like the Aragon and Adcom amps I replaced with good quality class D amps such as the Class D Audio, Emerald Physics and the D-Sonic amps I replaced them with.
     I don't know which class D amps you auditioned in your system and whether they'd be generally considered good quality class D amps.   However, I noticed you finally settled on a Pass class A/B amp for your system.  I would consider almost any Pass class A/B amp to be beyond 'good' and suggest you were comparing a possibly good class D amp or amps to  'one of the best' class A/B amps available.  I'm not surprised you preferred the Pass in this comparison but would point out that this is a somewhat apples to oranges comparison.
      I think a more worthwhile comparison for you would be between your Pass amp and Mola Mola Kartuga or Merrill Audio Veritas mono-blocks that are in a more similar quality and price range.
     You seem to be very pleased with your Pass amp's performance in your system and I have no interest in trying to persuade you to do anything but enjoy it.

Tim

I would consider almost any Pass class A/B amp to be beyond 'good' and suggest you were comparing a possibly good class D amp or amps to 'one of the best' class A/B amps available.
   I think a more worthwhile comparison for you would be between your Pass amp and Mola Mola Kartuga or Merrill Audio Veritas mono-blocks that are in a more similar quality and price range.

All Class-D's today have the same problem. The switching frequency is too low to be filtered out effectively completely with the Class-D's output filter, without effecting the upper mids and highs.

In the future when technology allows the switching can then be much higher to allow the output filter to do it's job properly and cut out all the switching frequency noise without effecting the audio band.

Cheers George  

" All Class-D’s today have the same problem. The switching frequency is too low to be filtered out effectively completely with the Class-D’s output filter, without effecting the upper mids and highs.

In the future when technology allows the switching can then be much higher to allow the output filter to do it’s job properly and cut out all the switching frequency noise without effecting the audio band."

Hi George,
As we’ve discussed on several other threads here on Audiogon previously, I’m still not convinced of your theory because of 2 reasons:
1. I have never heard any sonic anomalies in the mids or highs in any class D amp I own or ever listened to and I’ve never heard anyone claim they exist except you.
When I first read of your theory on another thread, I spent significant time listening to my system for anything remotely amiss in the upper mids and treble but never heard a hint of any issues. Since I can’t hear what you vaguely describe as ’affecting the mids and highs’, then these purported sonic anomalies don’t exist for me and likely many others so there is nothing to be remedied with higher switching frequencies.
I’ve previously requested you describe what these sonic anomalies specifically sound like so I can more easily identify some semblance of one. You have failed to respond every single time; which could mean your theory is false and you can’t describe the anomalies because they don’t exist, your theory is true and there actually are anomalies but they are inaudible to humans or you just fabricated your theory and are just messing with us.
In an effort to keep an open mind on the subject, however, I stated the following in my prior post:
" I also believe there may be poorly understood and unidentified sound artifacts with class D amplification that some are able to hear that others, like myself, are unable to detect. At this point, it’s hard to prove but still a possibility."
2. There is absolutely no scientific evidence or even any mention to support your class D theory that the switching frequencies are currently too low and cause negative affects in the audible frequency range.
Need proof? Google "class D switching frequencies are too low" and you just get references to your audio forum comments, no scientific or really any evidence whatsoever to support your theory.
I included my statement in my last post in an effort to be fair and remain open minded but you’ve made me regret it. Your continued adherence to a theory you are continually unable to prove at some point becomes pointless and is just a theory best abandoned.
     Are you still unable to describe what these upper mids and treble anomalies specifically sound like?  Have you ever actually heard any yourself?   Please do not respond until you’re able to present, or at least attempt to credibly falsify, some evidence to support your theory.

Tim