Article on Philips prototype digital amp

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Kjeldsen

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#1
A few years ago (2-4) I read a very interesting article in a hi-fi magazine. It was one or two authors that visited an engineer from Philips. He had developed a digital amplifier (prototype), which worked with 8 different digital amplifiers in parallel per channel. It was fed directly with a DSD signal from a SACD machine. Is there anyone out there that can remember what magazine it's from?
 
#2
There was an article in the German HiFi magazine "Stereoplay" in june 2002 (nr 6) . In this Testspecial "Die neuen Digitalamps-das Aus fuer unsere verstaerker" the Philips PPDSD system was discussed.

In that Philips kitchen a lot of beatiful things are cooking. Unfortunately most of it never gets to the market.
(I heard Philips electrostatic speakers driven by an optical isolated high voltage transistor amplifier!)

Ward
 
#10
Anyone trying the philips Class D implementation

Is anyone planning on trying the TDA8924?

Is it the UCD amplifier discussed on the classd.org site that got such a good wrap? Specs look reasonable (comparable to the competition) and the implementation looks to be easy. The UCD amp on classd.org mentions a zero feedback system with feedback (??) taken after the loop filter, but looking at the TDA8924 specs there is no feedback path after the filter so I guess its not the UDC design.

The other interesting thing about this chip is that it mentions high power supply ripple rejection, yet most class D implementations have very low or no (eg. Equibit) supply rejection.

Regards,
Dean
 
#11
Strange, Dean that people of the UCD forum didn't reply on this earlier....
Guess they are still watching the datasheets.

And yes, will try this one as soon as I get my hands on a sample.

BTW can you imagine a better diy-info including pcb and bom.
 
#12
Hi,

Judging from the authors own words:

Now, the technology (if you can call a circuit with 16 transistors that) to deliver low output impedance with frequency-independent low distortion in class D exists. Built with audiophile-grade parts it'll scare the pants off any high-end amp (while I'm the designer of that circuit and thus some care reading this statement is warranted, I do have a lot of serious folk to back up my claims). Of course, having these characteristics it sounds more like other high-end amps than that it sounds different, in the same vein as that the best tube gear and the best solid state gear don't differ by miles in sound.
Click to expand...

TDA8924 is certainly not UCD.

Best regards,

Jaka Racman
 
#13
Hi,

Judging from the authors own words:

Now, the technology (if you can call a circuit with 16 transistors that) to deliver low output impedance with frequency-independent low distortion in class D exists. Built with audiophile-grade parts it'll scare the pants off any high-end amp (while I'm the designer of that circuit and thus some care reading this statement is warranted, I do have a lot of serious folk to back up my claims). Of course, having these characteristics it sounds more like other high-end amps than that it sounds different, in the same vein as that the best tube gear and the best solid state gear don't differ by miles in sound.
Click to expand...

TDA8924 is certainly not UCD.

Best regards,

Jaka Racman
 
#17
Hi,

technical data of "One of the best analog class D at this planet" (Yamaha DVR-S120) see picture:

also see Yamaha's best analog class D amplifier Yamaha MX-D1

Best regards,

Jaka Racman
 

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#20
Dear EDUM:

Nice to know someone in Philips!!

I would like to know in early 90's Philips have a set of 900 series Hi-Fi Component, one of the system is DSC-930 and DSS 930 Digital Speaker, the amplification of the Digital Speaker is Digital Amplifier or not???

And I have a DCC player, no where can repair it... will Philips Holland still able/willing to fix it.???
 
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