Fully balanced. Not the same as balanced.

Discussion in 'Soundgear' started by The Pirate, Mar 21, 2019.

  1. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    Today, on a different thread was asked what is the difference between a balanced and fully balance signal. Since there seems to be a lot of confusion and speculation I decided to create this thread to explore what a fully balanced signal is.
    In a nutshell, fully balance is a fully balanced signal path from start to finish. That is an entirely differential balanced signal path from input to output; the audio signal never unbalances. It is done by providing identical internal signal paths for both the "non-inverting" and "inverting" audio signals. It is said to yield 3 dB better dynamic range.

     
    Last edited: Mar 21, 2019
    • Like Like x 3
    • Interesting Interesting x 2
    • Useful Useful x 1
    • List
  2.  
  3. Lieglein

    Lieglein Audiosexual

    Joined:
    Nov 23, 2018
    Messages:
    926
    Likes Received:
    521
    Thank you. :shalom:
     
  4. Andrew

    Andrew AudioSEX Maestro Staff Member

    Joined:
    Oct 24, 2011
    Messages:
    1,981
    Likes Received:
    1,201
    Location:
    Between worlds
    So it's just like dual mono topology?
     
    • Funny Funny x 1
    • Interesting Interesting x 1
    • Useful Useful x 1
    • List
  5. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    They are 2 different things. You can have a balance dual mono amplifier or a fully balanced one. Dual mono is treating 2 channels totally independent from one another.
     
    • Agree Agree x 1
    • Interesting Interesting x 1
    • Useful Useful x 1
    • List
  6. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    • Interesting Interesting x 3
    • Useful Useful x 1
    • List
  7. Andrew

    Andrew AudioSEX Maestro Staff Member

    Joined:
    Oct 24, 2011
    Messages:
    1,981
    Likes Received:
    1,201
    Location:
    Between worlds
    I would be a bit skeptical about using balanced or fully balanced for other use than signal transmission. There's a lot of snake oil surrounding the 'balanced headphones' concept. Larger transducers are not very different in that aspect.
    Star ground tends to work the best - while balanced technically 'work', and does provide voltage advantage in peak swings, also is more prone to crossover distortion and elevated noise floor.
    IMHO, there's no need to reinvent the wheel.
    https://benchmarkmedia.com/blogs/application_notes/audio-myth-balanced-headphone-outputs-are-better

    http://nwavguy.blogspot.com/2011/05/virtual-grounds-3-channel-amps.html
     
    • Interesting Interesting x 2
    • Useful Useful x 2
    • Funny Funny x 1
    • List
  8. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    If your D/A/C and amp are unbalanced, then your "balanced" headphones are not really balanced .
     
    • Like Like x 1
    • Agree Agree x 1
    • List
  9. Andrew

    Andrew AudioSEX Maestro Staff Member

    Joined:
    Oct 24, 2011
    Messages:
    1,981
    Likes Received:
    1,201
    Location:
    Between worlds
    True, but ultimately, the transducer doesn't "care" if it's fed two inverted signals or one in-phase and ground.
    https://benchmarkmedia.com/blogs/application_notes/balanced-vs-unbalanced-analog-interfaces
     
  10. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    In a balanced set you have twice the voltage in the output to your balanced phones plus reduced sensitivity to external electrical noise. This will increase the headroom and imaging... at least in theory. :yes: I would like to try something like this:

    fullybalanced.gif

    And this:

    balanceddigital.gif

    https://www.headphone.com/pages/balanced-headphones-guide
     
    Last edited: Mar 21, 2019
    • Useful Useful x 2
    • Like Like x 1
    • List
  11. Oy vey! Right first of all you need to understand balanced. A non-balanced mono connector uses two connectors, a mono balanced uses at least three and usually fully four.

    You understand NULL summing, right? An exact out-of-phase signal completely cancels the in-phase original giving NULL. It's the same idea on cables. You have a common (which is properly seperate from the ground running through the outer braid) the common being one connection. There's the 'hot' side of the signal (the in-phase original) and the cold, the 180 degree out of phase copy signal. That makes three and a ground.

    [​IMG]

    The idea is that if any interference affects the signal in the cable, it will affect both sides, hot and cold, in exactly the same way. So when the hot and cold arrive at the other end, and the cold get phase inverted and summed back over the original, the interference will NULL itelf out.

    And it does. Thios invented by a Dude called Clark (IIRC) in the fifties. All balanced connectors carry Pro (not consumer) voltages.

    [​IMG]

    Now these bad boys are not fully balanced, the tip and ring are carrying hot and cold respectively but the sleeve and casing have the common and ground combined. Perfectly adequate in most cases.
     
    Last edited by a moderator: Mar 21, 2019
    • Like Like x 2
    • Useful Useful x 2
    • List
  12. EddieXx

    EddieXx Audiosexual

    Joined:
    Sep 13, 2015
    Messages:
    1,316
    Likes Received:
    759
    darn, always something new to learn, it freaking never stops...:snuffy:
     
    • Agree Agree x 2
    • Like Like x 1
    • List
  13. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    Those are the wisest words I have heard in this Forum. :guru: It does not matter for how long you have been an engineer, a producer, an aficionado; everyday there is something to learn. One of my favorite quotes is by Jiddu Krisnamurti:

    "There is no end to education. It is not that you read a book, pass an examination, and finish with education. The whole of life, from the moment you are born to the moment you die, is a process of learning."

    This Forum is an inextinguishable fountain of information for the novice, as well as the seasoned members. Everyday we ought to thank @SAiNT, @Andrew, @Olymoon and other Mods for making it possible for us to enjoy this ride.:bow:
     
    • Like Like x 2
    • Agree Agree x 1
    • Love it! Love it! x 1
    • List
  14. That's why, back in the day, if you wanted to be an audio engineer you spent two years doing three things: degaussing tape heads, soldering balanced connectors and listening to the man.
     
    • Like Like x 4
    • Agree Agree x 3
    • List
  15. Gyro Gearloose

    Gyro Gearloose Audiosexual

    Joined:
    Jul 8, 2019
    Messages:
    4,237
    Likes Received:
    1,846
    Location:
    Germany
    :yes::crazy:
     
  16. The Pirate

    The Pirate Audiosexual

    Joined:
    Dec 20, 2018
    Messages:
    5,183
    Likes Received:
    4,405
    Location:
    NOYMFB
    You forgot to mention, making coffee and playing waiter.
     
  17. AudioTee

    AudioTee Kapellmeister

    Joined:
    Oct 19, 2018
    Messages:
    142
    Likes Received:
    60
    Wow, that brought back an old school memory from the 5th or 6th grade (we're talking decades here); During one of my "elective" class periods I signed up for, I was to help out a teacher and one of my duties was to degauss (she used the age appropriate term demagnetize back then) all the tape recorders she had in the class room. It required me to pass a device over the tape heads. Not sure what she used those recorders for as I wasn't one of her regular students.
     
  18. Got to pay yer dues if you want to record the blues.
     
  19. And fetching the talent her Kumquats.

    I did once, on such a shopping errand succeed in getting off with a backing vocalist by saying "You lay!" to her, followed by "Oil Of, one bottle." Life was simpler then.


    [​IMG]
     
    Last edited by a moderator: Jul 27, 2019
  20. Blue

    Blue Audiosexual

    Joined:
    Sep 6, 2015
    Messages:
    1,807
    Likes Received:
    954
    So does that mean an unbalanced signal must be a consumer voltage,-10dBV?Or not necessarily ?
     
  21. It can be anything you want as long as you're willing to gamble your hardware on it. It's pro, or it's consumer, or it's run away screaming.
     
Loading...
Loading...