Class D is just Dandy!


I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.

That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.

For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.

Please share your experiences with class D amps!
erik_squires
" IMHO I find class D amps to be less musical then Class A amps. I tried several class D amps and to my ears they lack the midrange, rhythmic
space, texture, air and less involving compared to good Class A amps.Something just seems to be missing musically to my ears. But to each his own. I'm not a audiophile snob I just know what makes my finger snap, head nod and foot tap."

Hi bluesy1,
     I understand.  I think it's a good and healthy thing that there's such a wide variety of amps currently available that individuals can tailor their system sound by choosing an amp that matches their sound preference.  
    Sound preferences are as unique like fingerprints and snowflakes.
    Your snowflake, bluesy1, seems to fall into group#3 from my last post.
     I'm glad you found a system sound you prefer with your class A amp.
Enjoy,
  Tim

I have had Class D amps from Classe (Sigma 2200i), Auralic (Merak Mono Blocks), PS Audio (HCA-2) and currently use a Lyngdorf TDAI-2170.  The Lyngdorf and Classe amplifiers were designed in-house and didn't use off the shelf modules.  Don't know if that is good or bad.

I don't know why people have to defend or overly praise Class D compared to other amplifier topologies when the end result is if you like it then keep listening.

If you like Class D, great, but perhaps some of you fanboys can tone it down.  Many of us are tired of hearing your opinions, and it is pretty obvious you are biased so your opinion doesn't mean a lot to the community at large.
It is the notion that Class D switching speeds are the cause, and that someday they’ll be fixed that irritates me.

If you guys are going to point a finger, get the whole story right.
It’s not the switching speed per se, but the output filter that has to try to get rid of it without any detrimental effects down into the audio band that’s the problem.
  
That’s why Technics with their $20k SE-R1 class-d has striven for double the switching speed, so then that output filter can do it’s job properly without much detrimental effect down into the audio band.

Cheers George
George, its more complex than that.

The reason Technics is switching so fast is to reduce distortion. The filter has little to do with it. At their speeds, the inductance of the speaker is sufficient. So their filters are mainly concerned with preventing RFI.

Keeping the switching speed high is important for resolution, and decreases distortion. The problem is that the faster you switch, the more time has to be alloted to allow the devices to turn off before its mate can be turned on.

This waiting time is called 'dead time' and increases distortion. so there's a bit of a catch-22: the more you try to decrease distortion by increasing switching speed, the more dead time you have to have and that increases distortion.

Technics' solution is by using Galluim Arsenide devices that no-one else can get, which are a lot faster (and can switch considerably faster than they are actually being switched in the amp). The reason they are doing this is to minimize dead time, and so have created one of the lowest distortion Class D amps made.

We're taking a different approach. We found a way to eliminate dead time altogether. This allows us to switch at a lower speed and still get lower distortion, or switch at a speed Technics is doing it, without having to use devices that are as fast.


" 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