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ADVC-G1 Audio Out Greatly Reduced

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  • ADVC-G1 Audio Out Greatly Reduced

    Product: ADVC-G1 Any In to SDI

    Input: 480i video/audio
    Video Port: Y/CVBS

    Problem Statement:
    The audio output embedded in the SDI OUT is objectionably reduced. I don't remember the numerical magnitude but would estimate it is -18 to -20dB. The audio can be restored to 0dB in post using any ordinary audio editing tool and appears to be satisfactory.

    I have confirmed that the problem is not with the original audio source by downloading the same video using another device (ADVC-300).

    The ADVC-G1 +4dB DIP switch option is engaged. If it makes a difference it is too small to see without careful editing inspection.

    Note: the G1 BNC output is being fed to an Epiphan AV.io-SDI device which delivers USB 3.0 video. I have not confirmed that the loss does not occur in this device. it just didn't occur to me to check but I would not expect it to be the source of the problem.

  • #2
    That was back in May when I posted this. Still nobody has anything to say.

    The DIP switch 4 allows a selection of +0dBu or +4dBu audio gain. The position of this switch makes no difference in the captured audio.

    We've got to do better than this, folks.

    Comment


    • #3
      MY WORKAROUND:

      Some might call this a solution but I will call it figuring out how to make something deficient provide satisfactory results.

      I insert a stereo amplifier between the G1 and the A2D converter. It was actually a mixer board not intended to provide any gain so I am wondering if we are talking an impedance mismatch.

      Anyhow, I don't have to normalize the audio as a second step after the download.

      Comment


      • #4
        I am guessing that very few people here have that device. I do have it and have never had any audio problem with it.
        1: 3970X Threadripper, Asus ROG Strix TR40 E Gaming, G. Skill Trident Z Neo 128G DDR4 3600, EVGA GeForce RTX 2080Ti, Samsung 970 EVO M.2 1T, Intel 660P M.2 2T (2), Seagate Ironwolf NAS 12T, Enermax TR4 360 AIO, Lian Li 011 DXL, AJA Kona 4, Asus ROG Thor 1200

        2: i7 6950X OC to 4.5GHz, ASUS RAMPAGE V EDITION 10, Corsair Dominator Platinum 64G DDR4 2800, SAMSUNG 950 PRO M.2 512G, GeForce GTX 1080ti SC Black, Corsair AX1200i, Phanteks Luxe, 16T RAID HGST Deskstar NAS 4T, Corsair H115i AIO, BM IP 4K

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        • #5
          if using analog audio inputs from semi pro or domestic decks, 0db will give you a much louder capture sound than +4db

          +4db is suitable for pro and broadcast players that have XLR balanced output only
          Anton Strauss
          Antons Video Productions - Sydney

          EDIUS X WG with BM Mini Monitor 4k and BM Mini Recorder, Gigabyte X299 UD4 Pro, Intel Core i9 9960X 16 Core, 32 Threads @ 4.3Ghz, Corsair Water Cooling, Gigabyte RTX-2070 Super 3X 8GB Video Card, Samsung 860 Pro 512GB SSD for System, 8TB Samsung Raid0 SSD for Video, 2 Pioneer BDR-209 Blu-ray/DVD burners, Hotswap Bay for 3.5" Sata and 2.5" SSD, Phanteks Enthoo Pro XL Tower, Corsair 32GB DDR4 Ram, Win10 Pro

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          • #6
            I am wondering if this is a problem or flaw with my G1 unit not observed on other units.

            The problem suggests an input impedance anomaly since my workaround is to route the audio through an audio mixer at 0dB gain. In theory there should be no difference in the ADVC G1 audio output whether the audio in comes from for example a VHS (or camcorder) audio line out or my mixer line out fed from the VHS with 0dB gain.

            This unit has also been giving me random freeze-frame anomalies from the very start as if the video stream input has ended. It is impossible to repeat these. They are random showing up once every one or two hours of use.

            Comment


            • #7
              I believe that the ADVC300 is designed for consumer-type audio sources with a nominal output level of -10 dBV. It also offers some audio gain adjustment.

              The G1 is for professional sources with nominal outputs of 0 or +4 dBU. Thus the audio embedded in the digital stream will be on the order of 10 dB lower with the G1 given the same source. Perhaps more depending on the output impedance of the source.

              Many current consumer line outputs have a source impedance on the order of 1K to 2K ohms, but older gear may be higher. Not sure what the input impedance of the G1 is but I would expect it to be around 10k.

              Depending on the mixer it may have a nominal line output of +4 dBu at 0dB on the meters with around 18 dB of headroom and a 120 ohm output impedance. Also it may consider 0 dB for a RCA consumer line input to be -10 dBV signal. It will depend on how it is configured.

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              • #8
                SOLUTION: The problem was an impedance mismatch.

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