Are Class D Amplifiers really "digital"?

[sandyk]

 #30

[sandyk]

6 minutes ago, kumakuma said:

@sandyk

 

Please leave this thread or tell us why you feel the need to mark every post in this thread as off topic.

Better still, you leave this Sub Forum as you are going against the main reason many members requested it. 

It was asked for as a digital free area where Vinyl etc. could be discussed without opposing views from the members who prefer pure analogue. 

[sandyk]

35 minutes ago, kumakuma said:

 

This only makes sense if you can prove that Class D amplifiers are indeed digital.

Tom

Please stop trying to  turn this area into that which was not originally asked for by many members over the years.

 It is far too divisive , and may result in PMs sent that would almost certainly result in the banning of their senders if they were reported .

 This has already happened in this Sub Forum, but you may already be aware of this ?

 

Alex

[sandyk]

8 minutes ago, kumakuma said:

 

Please leave if you have nothing of value to share and, if you've got a problem with this thread, take it up directly with Chris.

Discussions like this are best held in the Objective area of the forum  .

[sandyk]

2 hours ago, fas42 said:

Which amplifier should give you the better performance, looking at those two AP graphs, at normal, rather than extreme listening levels? 😉

 

Surprise, surprise ... the first is of that extreme cost amp mentioned by Putzeys; the second is of a DIY construction project of a 20W class A unit using normal topology, published in a hobbyist magazine in 2007 ... 😁.

 And that was using components that weren't selected for matching., where even better results were achievable.

 A little more work in the PSU area, as well as close matching of the differential input pair further improved it audibly 

Their ULD series of Class AB amplifiers would easily outperform that one too.

[sandyk]

From Silicon Chip magazine's Class D Amplifier.

[sandyk]

2 hours ago, 57gold said:

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.

 

"The Merrill Element 118 monoblock amplifiers and the Merrill Audio Christine preamplifier are priced at $36,000 and $12,400 respectively. "

 They would want to be bloody good for those prices, wouldn't they ?  

[sandyk]

3 hours ago, Miska said:

I guess Purifi doesn't go flat to 100+ kHz bandwidth either?

This isn't restricted to Digital amplifiers either, with many Analogue amplifiers having an Input filter well below the actual capabilities of many of them.

[sandyk]

2 hours ago, 57gold said:

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.

According to that reasoning, then anything greater than 24 bit 48kHZ, including 24/96, 24/192, SACD and DSD is a waste of time ,yet many prefer SACD with it's 50kHz capabilities over RBCD 's 16/44.1kHz, with many also appearing to prefer higher resolution DSD over SACD.

[sandyk]

8 hours ago, 57gold said:

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?

 Perhaps it's also about the rise and fall times of the envelope in the audible frequency range ?

I also get an improved performance from headphones such as the ATH M70x which have an extended  response of sorts from 5 to 40,000Hz.