Mytek slams Hypex in Stereophile Amp Review

I'm not so sure about it being possible to modify the modules themselves. I believe that they are pretty fixed.
Definitely possible - Rogue does it.

Rogue adds a tube input stage to sweeten the sound from the Class D output stage. This is a good example of adding a house sound.

Boutique amp makers are under a lot of pressure to differentiate their products from the module, which is also branded. Ice has bundled a power supply with the module, leaving "amp makers" scrambling to find tweaks for the copywriters to wordsmith. 

Things are changing though. Module makers realize that boutique amp makers want more control so they can impart their house sound. Hypex has a module that they won't sell to DIY.

 Anyway, it's interesting to sit on the sidelines and watch a newer market develop inside of our dinosaur hobby. ;-) 

@addyson815

If your going to copy and paste something from an article, you shouldn’t do just part of it.

There is a perfect refutation of this in Dostoevsky's Crime and Punishment.  I wanted to quote the part but ... Oh come on?? 

Rogue is a poor example of an amplifier. I have little ATCs that Rogue couldn't drive comfortably.

Class D amps remain controversial in high-end circles. I did a lot of reading about them before finally buying one (a used Wyred4Sound ST-500 built around an ICEPower core) to use w/my ATC SCM12 Pros. I was struck by how balkanized much of the commentary was: armed camps w/Class A and AB lovers on one side, and Class D lovers on the other. And the Class D ranks were riven with dissent over the positive/negative attributes of various amp cores (Ncore vs ICEPower vs Pascal). 

I don't have a pair of big speakers w/subs built in to test the Wyred4Sound on. But I can tell you it drives these ATCs extremely well. Among other things, I'm getting the best bass I've ever heard from a 2-way speaker. With a Marchand external/electronic crossover & sub in the system, I don't need anything below 80Hz from the ST-500; but I've done plenty of listening without the sub, and the bass is very fine--impactful & tuneful all the way up through the upper bass. Plus there's none of the etched upper mids or treble one kept hearing about with Class D amps 10-15 yrs ago.

Does that mean I'd use Class D if I had a big, expensive living room system? Maybe, maybe not. But IMO, Class D is definitely "on the table" now as a quality sonic option in various high-end applications.