Class D is just Dandy!

" It's interesting how some defenders of Class D amps go to such lengths to classify the critics of these amplifiers as a minority, yet then go on to claim that the critics are prejudiced. Hmmm ...  "

Hi cleeds,
     Sorry, I'm not understanding your point.
     I really didn't go to great lengths to classify the class D detractors I've  read responses from since I became interested in this technology about 5 years ago.  Just a few minutes recollecting, a few classifying those I recall from Audiogon and other forums and a few minutes detailing my thoughts.
     In retrospectively considering and gauging the totality of posts I've read about class D in the past 5 years, I have little doubt that supporters of class D are in the majority and detractors in the minority. 
     I have no doubt that various forms of bias were evident in many of the class D detractors' posts.  Here are some of the major forms of bias I recall:
1.  Bias in the form of claiming class D was only good enough for subs even though they'd never auditioned a good recent class D amp in their system. 
2. Bias in the form of claiming their current amp would outperform a class D amp even though they'd never actually auditioned one in their system.
3. Bias in the form of claiming the majority of class D amp's switching frequencies  were too low and negatively affected sonics in the audible range even though they provided no scientific or even anecdotal evidence to support their claims.
4. Bias in the form of claiming class D amps were inferior because the Damps they auditioned in their systems failed in their opinion to outperform their much more expensive tube or class A existing amp.

    There are more forms of bias I recall but I'm short on time right now.  
    Yes, I do consider class D detractors overall a minority and do consider many of their posts I've read over the past 5 years to be biased in some form.
   Your stating this and adding a "Hmmm..." does not amount to a coherent statement.  Please clarify.

Thanx,
  Tim   

If bias was a disqualifier, these forums would be dead quiet.

George, its more complex than that

You keep saying it Ralph, it’s the main cause for me, and even noted SS amp manufacturers like the highly regarded Solution amps deigner/owner ect.

"Cyrill Hammer (Soultion Amps) "if you want to have your product performing at the cutting edge it is not possible with today's known switching technologies. In order to come close to the performance of the best linear design we would need high-current semiconductors that provide switching frequencies of several MHz or even GHz."

I know your developing your own Class-D around present day technology.
We all know hiend isn’t how it used to be, and we all have to do what we can to make ends meet.
I wish you luck on your venture into Class-D, but to me and others like Cyrill it’s too soon yet to take the plunge.

Cheers George

Perhaps the ideas of Bruno Putzey hold some weight, as without his inventions and Hypex Ncore product, Class D amps might not yet have been in hifi amps. Here are his thoughts on Class D vs A and AB in an interview with Sound & Vision last year. 

S&V: Generally speaking, what are the key benefits of Class D versus the traditional Class AB and Class A designs that have long been favored by audiophiles?

BP: Efficiency and therefore the ability to construct amps that are powerful for their size. Only that. Modern Class D amps, in particular mine—ahem—sound good not because they’re Class D, but in spite of it. I can’t repeat that often enough. Left to its own devices, a switching power stage tries to do just about anything except amplify audio. You choose Class D to save energy but it’s all elbow grease after that. People don’t realize how much more challenging Class D is compared to Class AB. It’s truly an order of magnitude.


Read more at https://www.soundandvision.com/content/bruno-putzeys-head-class-d#Rp4w1mKbWublPse8.99

 "If bias was a disqualifier, these forums would be dead quiet."

Hi mapman,

     Good point. I agree that most of us, including myself, have developed biases along our audio journeys.
      I view my bias in favor of class D as based on research and personal experience using these amps. But I also realize that, in the end, all of our personal and particular biases are just our opinions.
   Rereading the previous 6-8 threads, I think the thread topic took a turn for the worse toward a discussion of bias and prejudice when I posted stating I liked the way erik_squires had characterized those claiming the switching frequencies used in most class D amps as being too low. This is erik's comment:

" It is the notion that Class D switching speeds are the cause, and that someday they'll be fixed that irritates me. It's a type of prejudice not born in evidence. It's the equivalent of "all feedback is bad" sales pitch for some amplifier designs."

I then posted my response below:

""Hi Erik,
     'A type of prejudice not born in evidence' is a very accurate and succinct way of describing how some class D detractors have a knee-jerk response, whenever class D is mentioned, of proclaiming a completely unproven theory that current class D switching frequencies are too low and negatively affect frequencies in the audible range."

     I thought that would be the end of discussions about bias and prejudice. However, cleeds than posted the following post responding to my post:

" It's interesting how some defenders of Class D amps go to such lengths to classify the critics of these amplifiers as a minority, yet then go on to claim that the critics are prejudiced. Hmmm ... "

     I found the point of cleeds statement above to be undecipherable and responded with a post asking him to clarify. In retrospect, I think I made a mistake posting my response since you responded to my post before cleeds responded to clarify.
   , I think your response of: " If bias was a disqualifier, these forums would be dead quiet. " was completely appropriate and accurate since my response standing alone, without a response from cleeds clarifying his point, just seems like me ranting about class D detractors' biases.
     I regret having to write this difficult post but I think it was important to clarify the sequence of responses to explain to readers of this thread that it was not my intent to turn the discussion toward the subject of biases and prejudice. My original intent was to complement erik_squires on his post, that succinctly and accurately described the efforts of a few class D detractors to claim switching frequencies are too low, when he stated " It is the notion that Class D switching speeds are the cause, and that someday they’ll be fixed that irritates me. It’s a type of prejudice not born in evidence." Subsequently, it was my intent to have cleeds clarify the point of his post, which I hope he will still do soon.

     I hope this post clarifies things for all.
     In conclusion, I just want to state that, although I currently use class D amps and have admittedly developed a favorable bias toward or opinion of them, I don't think they're right for everyone and I know that others have developed a favorable bias toward or opinion of other amplifier types. I think that's just the way it should be.

Sorry about the confusion,
     Tim