Results 1 to 4 of 4

Thread: Good presentation on Digital Volume Control and Jitter

  1. #1
    VIP/Donor [VIP/Donor] amirm's Avatar
    Join Date
    Apr 2010
    Location
    Seattle, WA
    Posts
    15,768

    Good presentation on Digital Volume Control and Jitter

    Nice to see the silicon guys, in this case ESS, present such data. Here, they talk about differences between digital and analog volume control, and jitter how their special async sample rate converter does away with problems of filtering out jitter in a DAC:

    Amir
    Madrona Digital
    Founder, Audio Science Review Forum
    Contributing Editor, Widescreen Review Magazine

  2. #2
    Member Sponsor [WBF Founding Member]
    Join Date
    May 2010
    Posts
    1,844
    This was fascinating, Amir -- thanks!
    Vbr,

    Sam
    SPQCV

  3. #3
    VIP/Donor [VIP/Donor] amirm's Avatar
    Join Date
    Apr 2010
    Location
    Seattle, WA
    Posts
    15,768
    You are welcome. Good to see interest in these videos .
    Amir
    Madrona Digital
    Founder, Audio Science Review Forum
    Contributing Editor, Widescreen Review Magazine

  4. #4
    Addicted to Best!
    Join Date
    Oct 2010
    Location
    Elkhorn, NE
    Posts
    251
    ESS has had the digital volume control presentation part as a PDF on their website for several years.

    I have never figured out why he is using a 16-bit DAC for an example. 24-bit DAC chips have been around for a long time. I've been using only 24-bit and have had at least 24-bit volume control for over 10 years.

    He says on slide 5, "As a digital volume control operates on a fixed-width field (ie on that 16 bit number that the DAC receives) it creates noise because the DAC cannot make the fractional part of the number – And this is a large noise!"

    So I think he is saying that the noise is due to quantisation errors. If so, then accessing the 32-bit internal data path of the DAC isn't the only solution. You could also access a 64-bit internal data path of the playback software. This will be even more accurate than the 32-bit DAC. In both cases, software or DAC, the final output to DAC chip is 24-bit (slide 14 says the Sabre chip is 24-bit externally). Also, he doesn't mention that you can basically eliminate the noise caused by quantisation errors by using dither.

    The only noise a 64-bit digital volume control doesn't push down is the noise floor of the playback system.

Similar Threads

  1. Master Volume Control application on PC
    By edorr in forum Computer Based Music Server Forum
    Replies: 7
    Last Post: 05-28-2013, 02:22 PM
  2. Digital versus analog volume control - one more datapoint
    By edorr in forum General Audio Forum
    Replies: 13
    Last Post: 12-09-2012, 12:20 PM
  3. Digital Volume control
    By Vincent Kars in forum Vincent Kars On Computer Audio
    Replies: 15
    Last Post: 11-18-2012, 01:25 PM
  4. Tired of riding the volume control?
    By JackD201 in forum General Home Theater Forum
    Replies: 2
    Last Post: 10-19-2012, 07:27 PM
  5. preamplifier with a one of the kind volume control
    By tony ky ma in forum Power Amplifiers and Preamplifiers Audio Forum
    Replies: 0
    Last Post: 09-22-2010, 08:45 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •