nFORCE said:
Nice pics!
As far as I can quickly see in the schematic the gates in the 74HC14 control SMPS and UcD-clock in case of overload. The gates are not in the signal path!
The two small pots on the board control output bias.
May be handy when you want to connect ESL's. The factory not always adjust these very well. The outputs of my DFR9000 are around 20 mV.
marconist said:
The older sets are class D amplifiers, but not UcD !
This makes exactly the difference between between good vs excellent output amplifiers ......
The class-D amp you mention is originally used in the Micro set. For High power Mini sets, I am very sure that you will be able to find the same UCD inside
.... If I remember correctly, FWM779 : 2x250W and FWM589 : 2X200W both using 2 UCD module with BTL configuration ....
For Hts set, LX8300 and LX8500W both used UCD as well.....
classd4sure said:Some powered PC speakers were based on SODA.. what's the difference anyway?
SODA is self oscillating, UCD is also self oscillating.......
But the feedback path is different for SODA and UCD.
SODA feedback taken before the output LC filter (before the inductor).
UCD feedback taken after the output LC filter (after the inductor).
marconist said:Before I bought the DFR9000, I bought the servicemanual. (€25,- at
http://www.doknet.nl/eng/index.html
Its in PDF with all schematic's. The poweramp is indeed a "real" UcD with feedback behind the coil and the small print is build with components, so no IC's there. The (switching) PS is very complicated and that is probably the cause that the DFR9000 acts so good on pulse basses in modern music. You certainly do not miss big elco's.
marconist: Could you post the schematic of the DFR9000?
The user manual is no longer written by engineers it seems!
I found this in the glossary:
http://www.p4c.philips.com/files/d/dfr9000_01/dfr9000_01_dfu_eng.pdf
Noise Shaped Video
NSV™ is a new video format. It is designed to be easily streamed,
support any audio and video codec, and be usable on nearly any platform. Currently NSV™ utilizes MP3 for audio and VP3 for video.
The person that wrote the user manual just searched on the internet for NSV. I think he/she used this page as reference:
http://en.wikipedia.org/wiki/Nullsoft_Streaming_Video
Nullsoft Streaming Video is also NSV for short
I found this in the glossary:
http://www.p4c.philips.com/files/d/dfr9000_01/dfr9000_01_dfu_eng.pdf
Noise Shaped Video
NSV™ is a new video format. It is designed to be easily streamed,
support any audio and video codec, and be usable on nearly any platform. Currently NSV™ utilizes MP3 for audio and VP3 for video.
The person that wrote the user manual just searched on the internet for NSV. I think he/she used this page as reference:
http://en.wikipedia.org/wiki/Nullsoft_Streaming_Video
Nullsoft Streaming Video is also NSV for short
What's the whole deal about IC's or no IC's in a class D amplifier?marconist said:Before I bought the DFR9000, I bought the servicemanual. (€25,- at
http://www.doknet.nl/eng/index.html
Its in PDF with all schematic's. The poweramp is indeed a "real" UcD with feedback behind the coil and the small print is build with components, so no IC's there. The (switching) PS is very complicated and that is probably the cause that the DFR9000 acts so good on pulse basses in modern music. You certainly do not miss big elco's.
The analog preamp is build around the TDA7468D which I think is a sota audio IC.
If you open the box it looks very well build and has a fan to cool ps and pwramp! You can only hear it when you put your ear on the receiver. (That probably will change after a couple of years ..... so than I change the fan.)
What's the difference between these two?
