confused re: High Def HDMI/Component/DVi etc

Discussion in 'AV Receivers & Amplifiers' started by rozzar, Mar 28, 2006.

  1. rozzar

    rozzar
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    ok, shortly going to buy a new av amp and I want it to be fairly future proof for the next 5 years or so.

    I firstly want an amp that has upscaling. The Yamaha 650/750/757 etc have video up to component, but they do not specify high def compatibility (i.e. 1080 lines etc).
    Now, i thought you needed a digital connection (HDmi or DVi) to have a proper digital HD signal.
    Reading up on the old Denon 3805 here http://www.homecinemachoice.com/cgi-bin/displayreview.php?reviewid=4426
    says the the analogue component outs are fully HD ready- 100hz component level.
    Is there anyone who can really help me out please!
    Incidentally, what would be peoples recommendations please?
    Have seen that Denon 3805 for a good price (sub £500)
    And the Pioneer AX3 and AX5 are also around that price. Is the AX2 worth another £100?

    I haven't got a compatible display at present, but whatever i will get will be proper HD ready- be it projector or LCD.
     
  2. jackal

    jackal
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    You need to be looking at products like the Denon 3806/4806/AVCA1XV or pioneer VSX A2. But these products are out of your price range. Forget the 3805 (Although a great amp) as an upscaler as it does not have HDCP, and will only offer marginal benefits from upscaling composite and s-video to component. This amp will not upscale to HD. As far as I am aware you need to be looking at £1000+ plus for a HDMI upscaling amp.

    My advice would be to wait for a while and see what comes out. As HDtv becomes established, HDMI technology will filter down to all midrange amps
     
  3. justinh

    justinh
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    None of the current Amps will probably let you use 7.1 from HD-DVD etc except thru 7.1 line input. So you have not complete future proof currently for new HD DVD formats.

    See Yamaha UK's reply to this question at http://www.avforums.com/forums/showthread.php?t=321349
     
  4. AngelEyes

    AngelEyes
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    Sorry, as stated even some of the newest amps don't support HD sound so you will have to wait quite a while if you really want to be future proof... to be honest there will always be something new you don't have. My advice would be to enjoy what you can afford and upgrade as and when you can. You could spend forever putting it off... :)
     
  5. chris.

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    Yamaha RXV1600 upconverts and deinterlaces all inputs to HDMI for £699 or the RXV2600 upconvets and upscales too all for under £900! Yams sound better than the 4306 and VSX A2 as well imho. Only downside is a long wait for the 2600 as they are difficult to come by as they are so popular.
     
  6. jackal

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    I thought the yamaha RXV1600 did not upscale via HDMI? i.e. only switching function.
     
  7. chris.

    chris.
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    No one said it did?

    It does not upsacle (2600 does) but it does upconvert and deinterlace - otherwise the HDMI output could be 576i or 480i which are not HDMI standards - then you get problems like the Denon AVR 3806 has with certain screens not accepting the 480i/576i HDMI input. The 1600 deinterlaces all HDMI otputs (and will do his for component too) to ensure that the HDMI output conforms to the correct standard. Avoid any HDMI upconverting amps that do not deinterlace to HDMI - you will regret it if you do not
     
  8. Welwynnick

    Welwynnick
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    De-interlacing and upscaling are functions that are always performed by any flat panel display.

    Why would you want the AV amp to do it as well?

    Granted, video switching is convenient if you don't have a media box and you don't want spaghetti going up to the screen, but video processing doesn't belong in an amp.

    Oh, by the way, 480i and 576i are in the HDMI standard.

    Nick
     
  9. chris.

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    DVI (the HDMI video protocol) does NOT support 480i or 576i. Some devices may do but they do not form part of the DVI standard.

    HDMI specs allow 480i and 576i digital outputs which DVI specs do not. DVI requires at least a 480P bandwidth signal to be output. What does that mean? Well it means that if you are using DVI out (with or without HDCP it doesn't matter) then you will likely be sending a signal that is already de-interlaced to 480P/576P or perhaps scaled higher even. You will be limited in performance by the de-interlacing and scaling of the source devices electronics

    taken from http://www.convergent-av.co.uk/article1.html

    As you can see - this means that sending a 480i or 576i signal to a screen via DVI may result in no image or a distorted image - I have seen it where a 576i signal from a DVD player was directly conected by HDMI to a DVI (HDCP) projector and the image was in three segments - the right hand side on the far left, the centre on the right and the right in the middle! PLeeeease do NOT guess answers.
     
  10. alefsin

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    Chris, if you read the HDMI standard's document (available for free on www.hdmi.org), you see that HDMI supports 480i and 576i. Your observation that --DVI-- which is just a --subset-- of HDMI protocol may not support the low resolution interlaced modes correctly has nothing to do with a proper HDMI to HDMI connection.
    If you like to know some more deails: there is a minimum of 25MHz for the video pixel-rate (the max is 165MHz) in the HDMI standard. Now low-res interlaced mode have a lower pixel rate than this limit (e.g. 13.5MHz for 480i/NTSC). To make it possible for the HDMI compliant devices to support these modes, the HDMI standard includes a pixel-repetition scheme. I believe this pixel-repetition was not included in the DVI standard. So in short, HDMI is NOT just the same old DVI + HDCP + some audio channels.
     
  11. chris.

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    Do not disagree with this at all. I am simply stating the reason why it is necessary to include deinterlacing when upconverting to HDMI in an AV amp, as there are some on here who can not see why this is necessary - there are many projectors and screens that use DVI and will not accept 480i or 576i.
     
  12. alefsin

    alefsin
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    Your warning and the latest statement is perfectly valid. My previous point was purely technical. Please forgive me if my language was not the best it could be as English is not my primary language.
     
  13. Welwynnick

    Welwynnick
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    I never guess answers. I always read the specs. You might like to try it, rather than guessing that DVI is the HDMI video protocol, or that HDMI does not support 480i/576i.

    You make a valid point about the benefit of de-interlacing an interlaced source for the HDMI output, but the Convergent-AV quote ironically makes an equally valid point about NOT doing that. The context of the quote relates to the use of de-interlaced and upscaled digital video inputs to scalers. Where the source performs this processing, it undermines the ability of the processor to improve the picture.

    This arguement, of course, also applies to the output of the upscaling AV amp, which effectively becomes the source. If you were to connect the amp to a good scaler or display, the video processing in the latter would be undermined by the quality of the processing in the amp. Which is probably comparable to that of a budget HDMI DVD player.

    So you end up in the situation with the latest "must-have" system where there is video processing in the DVD, then again in the AV amp, then a third time in the display, only this time it finally scales to the actual display resolution. The first two stages almost never do that, but they still degrade the picture quality at each stage, digital or not. In practice, video processing also degrades the sound quality in each piece of equipment, too! What a mess!

    Rozza, in reply to your original question, 100hz should read 100MHz, which is the video bandwidth of the analogue channel. For reference, SD interlaced uses 5.8MHz of bandwidth, SD progressive uses about 13.5MHz, and 720p and 1080i HD both use about 75MHz. So 100MHz should indeed to sufficient for HD. Note that this is analogue HD, though. TO be HD ready and future proof, you really need DVI or HDMI digital video interfaces.

    regards, Nick
     

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