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
@erik_squires 

However as with all transistors, there is a lag between the command to switch and the actual full switch. This is call the dead time. This has been reduced over the years with faster transistors and also limited with feedback. But it is fast. Hence the apparent speed of Class D also.

Sorry, could you be mistaking "switching time" with "dead time?" 

Dead time is the consequence of switching time - i.e. time from the garage door switch is pressed (switch) to time you can actually move out of the garage - takes a while for the door to open.  

@lalitk   
"Class D tends to be fast, unless slowed intentionally or with a tube"  - Are you referring to mating Class D with a tube preamp/Linestage?

You can use a Tube stage to slow down the signal or other circuit designs in solid stage to do that as well. 

In reference to above comment, the end user should be able to reduce "Coherency Distortion" issues with a tube pre as pointed out in your Synergy 2 paragraph, right?

Coherency is very tough and you don't hear it until you hear something coherent. So the short answer is - it is really difficult to get it exact.



One thing I do not agree with Putzeys on is that reality is logical. Reality IS. We can understand it logically, emotionally, sexually, spiritually, intuitively.. or, hopefully, all of the above and more.
I would like to hear more impressions of that ATI amp...how is it performing now that it has a few days on it?
You can use a Tube stage to slow down the signal or other circuit designs in solid stage to do that as well.
Agreed- **and** FWIW, there does not have to be anything slow about tubes. Keep in mind that in order for color TV to have existed, tubes had to be able to operate with bandwidth over a range of multiple MHz.

Tubes are only slow because of the design of the circuit, not because of tubes in general. In fact you can build a class D amp using tubes as the output switching devices, and switch them at some really crazy high frequencies- in excess of 100MHz- and likely with no need for dead time circuitry. That's pretty fast! I'm pretty sure solid state isn't there yet (but that's off the top of my head; haven't checked).
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