Class D amplifiers have very little phase shift


Too many diagrams to post here, so I just blogged it:

https://inatinear.blogspot.com/2020/02/class-d-amplifiers-do-not-have-horrible.html

The 20 degrees at 2 kHz argument is bunk.
erik_squires
Here's the problem, I have two charts. Both from the same source.  Both clearly labelled.

Several people have used the first chart to claim it is the amplifier output phase chart. In fact, the actual amp phase is the second. Then George#3 (or 5?) rolls in and says that charts can't be trusted because (gobbledygook).  So... if charts can't be trusted, why is he relying on the first one to make his point????

Here we go, I added similar charts from a speaker simulator.

See the bottom. You have both output and impedance for the same speaker charted. Both have phase angles. They are not the same chart.

https://inatinear.blogspot.com/2020/02/class-d-amplifiers-do-not-have-horrible.html


Also, look at the phase angle for the output? I make damn good speakers. :) Others do too, but I am so proud of how well those two drivers integrated.
Above all, everyone, I want to point out that I’ve made 1 claim.

The impedance chart is being misused.


There are several great ways to argue that Class D has a lot of phase shift. Show your work. Show the chart. Post specifics. Find a review, or data sheet.

Instead we get personal attacks, conflagration of a number of possible Class D issues, but the people (person) who relies on that chart to begin with is completely unable to actually refute my claim.

I welcome any and all sources of credible data (public review, manufacturer data sheet, etc.) which expand our knowledge here.
TI has a nice Class D calculator tool.
http://www.ti.com/tool/LCFILTER-CALC-TOOL

I have 3 tube amps, 1 bipolar and 1 Class D.
Each has its strengths and weaknesses.

In over ½ c. no amp has ever had it all.
Ya do have to wonder about the obsession about phase and then throw it all away with 2nd order or worse or wire the midrange out of phase speakers... 



it’s a system people...