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
miner42,

     Nice story except for the part about your brother in law dying!
     It just illustrates another less discussed benefit of good class D amps; reliability.  
     Most understand that heat is generally the enemy of electronics and excess heat can cause premature circuit or part failure.  Class D amps generally run so cool they don't even use heat sinks unless an analog power supply is substituted for the cool running  switch-mode power supplies (smps) typically utilized with, and even now built into, the
 class D power modules. 
     This lack of heat buildup, I believe, can only benefit class D amps and increase their reliability and extend their lifespans as a result.
     I also believe the opposite is true of class A and A/B amps specifically because they run much hotter..
     Great sounding, very quiet, very neutral, relatively inexpensive,very detailed and powerful amps with low distortion, wide dynamics  and very detailed from top to bottom.  What else would you want to consider an amp type ideal?  Oh yeah, have it consume electricity like a virgin consumes birth control pills, keep its cool like Clint Eastwood and, while you're at it, make it as reliable as Old Faithfull.  

     'Mr, Old Faithfull', Georgehifi, predictably would add that increasing the switching frequency to 3-5 mHz would make class D perfect  My opinion is that this may be making perfect the enemy of the extremely good.

      What the Heck, though, if it'll nudge class D firmly into the 'Ideal Amp Technology' consensus, the brains behind class D are likely pondering this as we speak.

      If Bostrom at Anaview/Abletec, Putzeys at Hypex or Hansen at Pascal determine that a higher switching frequency would actually benefit the performance of their class D modules, I would not wager against them incorporating this improvement into their products.

      Unfortunately, I'm not technically knowledgeable enough to determine whether a large increase in the switching frequency would actually improve class D amp performance.  As I've mentioned before, I detect no sonic detriments to the current switching frequency operating in the mid 500kHz range.  Obviously, though, I've also never been able to compare a class D amp with a switching frequency in the 500kHz range to an amp with a switching frequency in the 3-5 mHz range.

     I'm also a bit perplexed on whether and how this switching frequency issue affects the Bostrom/Anaview-Abletech and Hansen/Pascal class D modules' performance since they both now operate utilizing Phase Modulation rather than the Pulse Width Modulation still being utilized in the Putzeys/Hypex, along with being utilized in most previous, class D modules.

     Sorry to get so Geeky about this, but I've read and paid attention long enough about class D technology to be dangerous without completely grasping the subject.  I think it would help me if someone had the time, expertise and ability to explain this further in layman terms.

Thanks,
  Tim   
higher switching frequency moves it further from the range of human hearing and enables "kinder, gentler" filtering
randy-11
higher switching frequency moves it further from the range of human hearing and enables "kinder, gentler" filtering

+1 many times over Randy, seems like your one of the few that get it here!

Just to add to that, the "gentle" filter is on the output speaker terminals, and has to take the full grunt (wattage) of what the amps gives out, it has to be "gentle" (low order), if complex it would soon fry up.
Or as Mark Levinson tried with $$$$ the No. 53 monoblocks, a higher order filter and massive to take the grunt, (as you can see by the 4 x chokes on each monoblock), but that has problems also as well as expensive, it wasn’t received very well.

http://www.stereophile.com/images/1212levin.side.jpg

Cheers George
Always fun to talk tech.... but I've been living with dreamy sounding amps for a while now. I don't need my switching frequency increased to have the best.

E
I'll lay money on it Eric your the one of the first to change to the higher switching speeds when they come available/affordable, hopefully soon, judging by Technics lead in this area of higher switching speeds.
 
I know I will sell my inefficient, hot, heavy, boat anchors just before it happens, before they become worthless, as will today's Class-D amps.

Cheers George