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
To sell a new product we must sell the problem first, so I can see where a lot of this is coming from.

I don't have a problem with listening to the new when it comes out.

I'm not easily swayed by naked kings though.

Best,

E


This should be an interesting read for some here. Alex Lidow, Ph.D.

CEO and Co-founder of EPC.co. And who happens to be the co-inventer of the Mosfet/Hexfet transistor

And now he is leading the way with this higher switching speed GaN-Fet transistor that Technics uses, in their limited SE-R1 Class-D poweramp.

Looks like the GaN Class-D modules have become available, maybe to everyone?

http://epc-co.com/epc/Applications/ClassDAudio.aspx

Cheers George
George,
Those have been on digikey with a 12 week lead time for at least 6 months or so.
I haven't heard of anybody including DIY using them or even ordering them.

The old time will tell saying is in full swing I guess.

Kenny.

"Tim,
Ofcouse I have read all this info before,I appreciate you taking the time to post all of this pertinent info so others can read it too."

Hi kdude66,

     Thank you, but I actually really enjoy reading the Audiogon and other audio and video forum threads on-line and contributing my version of the truth especially when I believe I have useful input based on personal knowledge or experience related to the subject being discussed.  
     Unfortunately, I had emergency open-heart surgery about 8 yrs ago and suffered a stroke immediately following the surgery when I was relatively young at 51. I recovered my cognitive and speech abilities rather quickly but I’m still trying to coax my paralyzed left limbs back into action. I decided to retire early after consulting with my cardiologist and neurologist and am currently on SS Disability Insurance with a reasonable but fixed income until I reach my actual retirement age in about 8 yrs.
I wasn’t prepared for how much I actually missed my job as an operations manager at a very large (1 million sq. ft), high volume, fast paced and highly automated distribution facility and the people I worked with, Oddly, my dreams often revolve around work and my former colleagues. I’ve even awakened many times in the morning thinking I need to still solve fairly complex problems or employee situations I was dealing with a few minutes earlier in my dreams.
     So, while I feel grateful I’m still on ’the right side of the grass’, I’m also grateful for this forum that enables me to keep learning from other members about this hobby I’ve enjoyed for decades and post my thoughts when I think I can contribute constructively on certain subjects.
     As my typically overly long posts indicate, I now have plenty of spare time to read and respond when I may be useful to forum threads, too.

     Like this thread for example. I initially learned of class D amps from positive comments on various audio threads. I purposely began researching all I could on the subject here and on other sites and I credit my own quasi-scientific readings on the over 60 yr history of class D amp development along with the forum posts of class D guru Guido Corona and a few other members with exceptional knowledge and experience.
After my older class A/B amp went belly up due to leaking caps a few yrs ago, it was the perfect time to take the plunge and start gaining some personal experience with class D and I bought my first amp, a Class D Audio SDS-440-CS stereo unit that was superior in virtually every aspect that audiophiles care about in an amp. I was so impressed that I replaced the other 2 class A/B amps I used in my combo 2-ch music and 5.1 HT surround system with relatively inexpensive class D amps; a Emerald Physics EP-100.2 stereo unit and most recently a pair of D-Sonic M3-600-M mono-blocks.
     When I read posts from members like georgehifi and randy-11 about a theoretical issue with class D amps switching frequencies needing to be dramatically raised to avoid affecting frequencies in the human audible hearing range without presenting any semblance of even anecdotal evidence that it’s true, makes me seriously suspicious of their true motives for spreading and trying to validate something that I highly doubt 99%plus of humans could even begin to detect, although I believe at least georgehifi has heard a good class D amp and acknowledged how good they currently are but is going to wait for his view of perfection. I’m not even sure if either one of these guys has personally heard any sonic anomalies from a class D amp.
As far as I’m concerned, they’re in my doghouse until they can cite a SPECK (as in Peewee Herman’s dog) OF EVIDENCE.

Tim



When I read posts from members like georgehifi and randy-11 about a theoretical issue with class D amps switching frequencies needing to be dramatically raised to avoid affecting frequencies in the human audible hearing range without presenting any semblance of even anecdotal evidence that it’s true, makes me seriously suspicious of their true motives for spreading and trying to validate something that I highly doubt 99%plus of humans could even begin to detect
By saying this, a little better explanation is needed.
It’s the output filter to rid that switching frequency completely, that is the problem, not the switching frequency by itself.
As that output filter has phase effects down to 5khz, the upper midrange and highs. And by moving it (output filter) and the switching frequency much higher, takes those effects at 5khz upwards by the same amount, hopefully passed 20khz.
Why I ask then are these transistors developments happening, if not to do anything good? Forest and trees.

Cheers George