High end Class D amps?

@mikem

Class D done right can sound very good

this is of course the correct answer... like any technology/format it is in the implementation quality, skill of the designer, the care in the voicing

over 300 posts in this thread... much heat very little light

people bellyache why a sub 1000 dollar class d amps sounds like crap... well there are cheap class ab amps and tube amps that sound poor too...  true for more expensive ones too...

Hello mikem,

     As I understand it, many class D power modules have traditionally had rising distortion levels as the frequency being reproduced increased.  This is what led to these amps sounding a bit overly bright or harsh in the upper treble region and listener fatigue.  I think this is what you were perceiving.
      I believe the new Purifi class D power modules, designed by Bruno Putzeys, have claimed to have solved this problem by significantly reducing distortion in the upper treble region through the use of global negative feedback levels in excess of 35%.  Figuring out how to successfully do this has proven to be a very difficult thing to do and is, therefore, considered a technology breakthrough.
     However, I'm not an expert on this subject and make no claims of having a complete understanding of it.  Actually,  I find this whole topic a bit perplexing based on my class D experiences.  For example, I use a pair of D-Sonic M3-600-M monoblocks in my system that are now over 6 yrs old and utilize Anaview/Abletec power modules that are at least as old technology wise.  Why do these amps provide upper treble frequency performance in my system and with my main speakers that is, according to my perceptions, very detailed and revealing without ever sounding harsh or bright?
     Do these amps or modules utilize some alternative method or technology to provide such high quality levels of performance?  Perhaps I'm boasting a bit about the high quality performance levels of these amps,  but the main factors influencing my inquiries are curiosity, a search for logical and reasonable explanations and the attainment of knowledge and understanding.
     My suggestions for you, mikem, are that you are likely to find very good class D amp options in a new Purifi module based amp, a new or used D-Sonic amp or amps or even other high quality class D amps.  As other experienced users have already mentioned, not all class D amps sound the same and I'm certain they all don't reproduce the upper treble frequencies in an overly bright, harsh or fatiguing manner.

Best wishes,
   Tim
      

@noble100  Thanks Tim.. Appreciate the response, but I’m not giving up my Inefficient, heavy Pass class A amp anytime soon..  It sounds too good and checks all the boxes that I find important in an amplifier, and it’s executed so very well. Appreciate the response and Happy Holidays !!

@jjss49  No doubt class D is getting better with each  iteration..  I’ve had several of them, Tripath, ICE, Hypex ..  Yet I will continue down the road of linear PS, inefficient Class A topology..  Experience has shown me that Class A gets the vocals,  textures, etc more Lifelike than other topologies..  Bruno Putnzey has really improved the Class D sound.. I’m sure it’s only going to keep improving too.. Each class type of amps have their strong and weak points.. like everything else.. I’ve moved on to different speaker/amp combination and I’m now enjoying music more and topologies less.
Happy Holidays !

If all you have heard is a stock Bel Canto Ref 600.....then you have no idea how good the latest class D is. The Ref 600s use a stock Hypex power supply, a stock Hypex NC500 module and an input buffer that is an integrated circuit powered by two three pin regulators.......and this is for $6K per pair. Now, Bel Canto has updated this amp (now called an e1x)) to make it a stereo amp using the same stock NC500 modules and a single Hypex power supply but finally they made their own discrete front end buffer for the amp......this amp is also $6K and you can read a review (that is completely worthless) on Stereophile. Let’s look at what VTV does....They will sell you a stereo amp with two Purifi modules (slightly better than the NC500s), a single Hypex power supply and their own discrete input buffer board with say Sparko Labs discrete buffers.........basically the same configuration as Bel Canto and the cost is $1500 delivered (including shipping) and 30 day money back. One quarter the price!!!! My modifications to the VTV amp cost $1050 bringing a totally tweaked Purifi based amp to $2600......less than half of Bel Cantos latest thang. The mods completely transform the amp. I actually mod the Purifi board (change the output coils to super OFC air core coils, use better caps on the output filter and bypass the power supply with modified Wima caps).

Bruno is just one of many people who are pushing class D further. The Merrill amps, the AGD amps, the new Technics amps ($10K pure digital integrated coming early next year...OMG!...check it out!), the Cherry amps, New Class D amps, etc. etc. are all fantastic sounding and completely designed by other people. The Purifi module is not "pure" sounding. My mods make it way more "pure". This game goes on and on. As these latest amps (and about to be released amps) get out for more people to hear then the reality of what class D is doing now will finally be known. I will be sending out one of my modded VTV/Purifi amps on tour......so get in line to see what is possible.

Class D is coming of age. Some are still too expensive for most (like the Merrill and AGD amps).......but my modded Purifi and soon others at $3K or less is what we need. The (to be released in Feb.) pure digital class D Technics integrated at $10K...is a preamp, amp, DAC and phono stage with wild distortion reducing stuff in it......so, it is really not that expensive (and you save space, have only one power cord, and no interconnects).