Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

590 Excellent

1 Follower


  • Rank
    5000+ Post Club

Profile Fields

  • Location
    Brisbane (ex-DTV Forum member)
  • Country

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. You obviously are well versed in calibration matters, @Tweaky! Yes I find gamma an important variable. And HDR, at this early stage, at times seems to cry out for different settings for different discs, with big variations being possible in the mastering of different 4K Blu-rays.
  2. Good for you. Unfortunately for me I find active glasses 120Hz insufficient as an alternation rate for 24fps 3D material. The motion looks mirage-like for my vision and lacks solidity. I find an alternation rate of 144Hz sufficient. The retailers offer very expensive cables and non-technical buyers assume these cables must be "better" if they are "dearer". And of course buying a cable requires no effort, compared with carrying out a calibration. One reason people don't do their own calibration is that reviews of better quality flat screen TVs and projectors often report that the factory calibration is close to correct. Another reason is that many movies these days have such heavy handed grading/editing of the colour that strong colour casts in the movie master (designed to provide a particular look) will tend to swamp any slight inaccuracy in the colour calibration of the display device. There have been a lot of articles about this. Here's one article that came up for me a moment ago in a Google search: - Why Every Movie Looks Sort of Orange and Blue One of the challenging issues these days is calibration for HDR, relevant for 4K 2D material.
  3. As you very possibly already know, to avoid distracting ghosting when viewing 3D movies that have high contrast between the Left and Right views, you need a display device with very low crosstalk. DLP projectors typically are good in that respect. I find my current passive 3D TV pretty poor for ghosting. My previous passive 3D TV was much better in that regard. But by far the lowest crosstalk I've experienced when watching at home has been from two BenQ DLP projectors.
  4. I'd insert the word "may". You may need to have a hash filter ...
  5. My post was intended for general readers of the thread, just to clarify that the issue here was switching vs linear. Sorry that my purpose wasn't clear to you, Muon.
  6. @Muon N', the reason I quoted your post supplying symbols for AC and DC, was that I was of the opinion that the OP most likely already knew the unit produced 24 volts direct current. That did not appear to me to be the OP's query. It appeared to me that the OP's query was whether it was a switching adaptor, as distinct from a linear one. As for "lore", switching power supplies are indeed held in low regard by a percentage of audiophiles. No doubt some switching power supplies used for hi-fi equipment, particularly early implementations of switching power supplies, have caused sufficient emissions to create an audible effect. In my opinion that is not likely to be an issue these days. Your opinion may differ.
  7. I'm not sure I agree with that lore. It is what it is. These days there are regulations for maximum permissible emissions from units such as the one pictured.
  8. The issue of concern for the OP was the "topology" of the conversion to 24V DC. It is audiophile lore that a power supply that uses the modern technique of switching is bad and that "old-fashioned" linear is good. A reason advanced for that view is possible Electromagnetic Interference (EMI) from a switching power supply. Switching power supplies tend to be capable of operating over a wide range. That is in evidence here from the input voltage range shown on the pictured unit, namely 100 - 240V.
  9. I see that the lengthy thread of which that post #13 forms part, teases out some of the practical difficulties in implementing a switching output stage (i.e. Class D) for audio amplification.
  10. Your concern about keeping things in the digital domain strikes me as a concern for purity/perfection. However, looking at the matter in perspective, it is relevant to consider that a class D audio power amplifier will typically be used to drive a loudspeaker system that will be far from perfect. (Also human hearing is far from perfect. And a digital source signal derived from a microphone using an ADC will be limited by the imperfections of the microphone.) As I understand the situation, the main advantage claimed of Class D audio power amplifiers is efficiency. There is no implied purpose of avoiding analogue to digital, or digital to analogue conversion. It would be interesting if the position of a loudspeaker diaphragm could be controlled with digital perfection, but that would be a different topic!
  11. On the same page you've linked to on Wikipedia, the following currently appears (under the heading "Error control"): The actual output of the amplifier is not just dependent on the content of the modulated PWM signal. The power supply voltage directly amplitude-modulates the output voltage, dead time errors make the output impedance non-linear and the output filter has a strongly load-dependent frequency response. An effective way to combat errors, regardless of their source, is negative feedback. A feedback loop including the output stage can be made using a simple integrator. To include the output filter, a PID controller is used, sometimes with additional integrating terms. The need to feed the actual output signal back into the modulator makes the direct generation of PWM from a SPDIF source unattractive.
  12. "Softer" you could overcome with a gain control. "Less dynamic" may be a Netflix decision to enable quieter parts of dialogue to be heard with the volume set at medium rather than at public cinema volume [i.e. very loud]. I've noticed insufficient bitrate allocation to the sound causing a strange wispy effect with some standard definition digital TV broadcasts. I'm also not a fan of the bitrates commonly used in Australia for DAB+ radio. Even the supposed 80kbps used for ABC Classic FM, I find distinctly deficient. My main gripe with TV sound in Australia is the PAL speedup we get with so many movies and sitcoms. (I can live with stereo rather than surround but I do very much dislike things being sped up from 24fps to 25fps.) I find Netflix sound similar to Youtube sound, but often it comes as 5.1 channel sound rather than just stereo. Netflix sound is probably comparable in quality to PAL DVD surround sound, but will be at the correct speed and pitch.
  13. The review video in the last few seconds shows a reduction in noise as displayed on the screen when the device was connected. However there is no way of telling whether the noise as displayed on the screen without the device was having an audible effect. The fact a change can be detected by a measuring device does not mean that the change will be audible. Claims made for the product such as these: Blacker Silence and Subtler Detail Widens and Deepens your 3-Dimensional Sound Stage are commonplace audiophile-speak. They tend to be made about any "tweak".
  14. I'd agree the 3D is well done, particularly considering it like many other recent 3D movies was produced using a computerised post conversion process rather than stereo camera live footage. (The source 2D live footage was shot in 2016 and 2017.) One could expect that the extensive CGI would have been rendered using two virtual cameras. I found the 3D strength in Spider-man: Homecoming a little exaggerated at times, but not excessively so, and this caters for the people who prefer their 3D to err on the side of being strong. I thought the faces of the actors were well done in 3D (unlike some other post-converted movies). Not everyone would find the plot, focusing as it does on the lives of teenage children, and in particular the 15 year-old Spider-man, riveting. I myself found the pace of the movie too slow. However it's a feel-good movie; with a strong ending (some interesting plot twists).
  15. PAL DVDs still fill the shelves at JB Hi-Fi and other outlets, with their relatively low bitrate Dolby (or sometimes DTS) surround sound. With movies this is typically with PAL speedup. At least with Netflix the speed and pitch of the dialogue and music of movies will be correct, even if the audio quality is not as high as with a Blu-ray version of the movie.
  • Create New...