Are Class D Amplifiers really "digital"?

[57gold]

Interesting (for pikers like me) interview with Michal of Mytek on development of his Class D amps after discussion of development of the company into Hi Fi from Pro Audio and their DACs in this article:

 

 

[57gold]

Michal of Mytek waxes enthusiastically about GaN transistors and their capability to operate at much higher speed.  Since read that these are used in Merrill Audio's and Technics' new SOTA amp offerings.  Are amps incorporating these units the missing link in achieving "analog like" digital amps?  

 

Have not heard any of these and understand that Mytek will introduce high priced mono blocks with this technology.  Have seen some evidence of boutique builders with plans to introduce amps with mid fi pricing with GaN transistors.

[57gold]

Thanks Firedog -  Read the article, comprehension was low on my part.  Understood that the positive aspects of GaN is offset by some negatives...so they didn't want to use them in their Purifi product.  

 

Wish they would develop a higher powered Purifi module, like 400 watts into 8 ohms.

 

Yes, sandyk, would hope the Merrill Audio stuff sound great for the freight.  A lot of "audiophile jewelry" in these new designs, casework, fancy footers, contrasting metal panels, high polish...in the pricing.  Give me a plain black box, and I'm good to go.  Though I would like it to be significantly smaller than the DNA-500 in my music room.

 

[57gold]

2 hours ago, barrows said:

Mr. Putzeys has stated that it is the plan to produce more powerful Purifi modules, I am sure they are just waiting a bit for sales to offset some of their development costs before they can introduce more products.

 

Thanks, thought I read that somewhere. 

 

Some one like Nord or Apollon or... will make a nice sounding, reasonably priced higher powered Purifi based amp when the new units are available. 

[57gold]

Another GAN amp in the works for $3K:

 

https://www.underwoodhifi.com/products/lsa-electronics

 

[57gold]

barrows, have you seen this fellows assault on implementing the Purifi modules with 3 transformers for LPSs for driver, input and output stages, Class A discrete input stage?

 

 https://lkvresearch.com/lkv-veros-power-plus.html

 

Be interested to hear of the choices you make as you work on yours.

[57gold]

Miska - Lots of specs on this site, graphs and charts that seem to address Purifi capabilities. Don't really understand the practical implications of them, but I'm pretty sure you do.  

 

https://purifi-audio.com/eigentakt/

 

Looks like frequency response rolls off above about 60kHz.  Been led to believe that most speakers are built to reproduce up to 20 -25kHz? And that most folks can't hear airborne sound above that level.

[57gold]

Personally, I do not understand how format relates to frequency response, nor most of the discussions here on digital technology and audio circuits.  Last science I took was Chemistry in high school, not AP like my 3 kids (their mother's family has multiple PhDs in sciences).  Never took Physics, took 2 history classes as a senior, flexible curriculum.  

 

So I was careful to say "was led to believe" in making my comment...which involved no reasoning.  An example of why I may have been led to believe this would be by looking at the specs on speakers.  Well regarded by some Wilson Audio speakers, their $38K Sasha has these specs for frequency response, "20Hz–30kHz ±3dB". To a piker like me, sounds like that's the range, plus a little, that folks care about hearing?

[57gold]

barrows - How are you liking the Purifi amp build?  

 

So, instead of a third party, discrete input, you are powering the "built in" driver with an LPS?

 

[57gold]

Cool.  Your build layout looks great.

 

Kind of ironic that you chose a case that has so much heat sinking when these are supposed to run very cool. Guess its dimensions help with optimal layout.

[57gold]

On 10/9/2020 at 8:52 AM, hopkins said:

 other than incomprehensible 6moon type reviews

 

Wow, I though I was the only one who held the opinion that 6moons reviews made absolutely no sense.  

 

Random babble for many paragraphs and sometimes, though rarely, a few words about how the gear being reviewed sounds in comparison to other similarly priced gear.  And even then, usually overwhelmed by one or more tangents about some tweak or cable or obscure recording...have given up reading their reviews out of frustration; when I get to the end of a review, I wonder why I bothered.

 

Believe the first review I read was one on the McCormack DNA-500, which was actually very informative and accurate.  I still have my DNA-500 and it rocks. It was written by Chip Stern, an outlier, who has a history of audio reviews and seems to understand how to describe the musical character of audio gear.

 

 

[57gold]

Firedog, I like to read. Probably get through two books a week on my Kindle, daily local paper, NY Times, Bloomberg news subscription...

 

Chip Stern's 6moons review of the DNA-500 was not short; it discussed info about Mr McCormack, the design choices he made on his products and development and sale of his company to CJ and took care to describe the sonic quality of the amp versus others he had reviewed.   My honors English teacher would have given him an A for staying on point and supporting his conclusions.  This approach does not seem to be the framework for many a current 6moons review these days.  

 

Agree that 6moons seems to comb the planet for new products from small, up and coming manufacturers...as far as you can get from Best Buy inventory, which is valuable.  Guess they can be seen as the other side of the coin from audisciencereview.com where a review is a bunch of measurements, boiled down to one number.