EVGA

question about 'balanced signal' on evga nu

Author
Post
Essentials Only Full Version
jeffswitzer
Superclocked Member
  • Total Posts : 126
  • Reward points : 0
  • Joined: 2018/09/28 09:14:55
  • Status: offline
  • Ribbons : 0
2019/01/21 19:24:30 (permalink)
On the EVGA nu page it says:
 
The AK4493 provides a fully-balanced output for low noise/distortion operation, and fed to a fully-balanced, iteratively-optimised, linear phase low pass filter formed by TI LME49724 fully-differential amplifiers, Audio Note resistors and Wima precision capacitors. The balanced signal is fed to the line stage itself, formed from an ADI AD8056 dual Op-Amp - selected for its audio quality - and seated in an IC socket for interchangeability – known as “Op-Amp rolling”.
 
The line outs are RCA (which I always thought were unbalanced) so I'm assuming the signal is only balanced until it hits the RCAs? Or is there a way to send a balanced signal out of the line out? If you can't run balanced lines out, then what is the purpose of a fully balanced output? A similar question, the line in is 3.5mm can i use a TRRS connector to input a balanced signal? Thanks for any insights!
#1

6 Replies Related Threads
    jll544
    Superclocked Member
    • Total Posts : 101
    • Reward points : 0
    • Joined: 2006/07/29 13:25:09
    • Status: offline
    • Ribbons : 9
    Re: question about 'balanced signal' on evga nu 2019/01/21 22:16:09 (permalink)
    jeffswitzer
    The line outs are RCA (which I always thought were unbalanced) so I'm assuming the signal is only balanced until it hits the RCAs?


    The signal is balanced until it hits the op-amp. The AD8056 outputs are single-ended, which is what goes to the RCA jacks:
     

    #2
    jeffswitzer
    Superclocked Member
    • Total Posts : 126
    • Reward points : 0
    • Joined: 2018/09/28 09:14:55
    • Status: offline
    • Ribbons : 0
    Re: question about 'balanced signal' on evga nu 2019/01/22 16:21:46 (permalink)
    jll544
    jeffswitzer
    The line outs are RCA (which I always thought were unbalanced) so I'm assuming the signal is only balanced until it hits the RCAs?


    The signal is balanced until it hits the op-amp. The AD8056 outputs are single-ended, which is what goes to the RCA jacks:
     



    Thanks, guess it makes sense in that you don't want to amplify any interference.
     
    Any idea on if you can used a balanced input into the line in or mic in?
    #3
    jll544
    Superclocked Member
    • Total Posts : 101
    • Reward points : 0
    • Joined: 2006/07/29 13:25:09
    • Status: offline
    • Ribbons : 9
    Re: question about 'balanced signal' on evga nu 2019/01/22 20:31:36 (permalink)
    jeffswitzer
    Any idea on if you can used a balanced input into the line in or mic in?


    It seems not possible. Looking at the back of the board, we can see how line in and mic in (4th and 5th jacks from the top) are wired:

    From each jack, we can see two thick traces (+1 thin trace) bringing signals into the board, so that would indicate L+R single-ended.  If it was differential, we should expect four thick traces from each jack.
     
    #4
    jeffswitzer
    Superclocked Member
    • Total Posts : 126
    • Reward points : 0
    • Joined: 2018/09/28 09:14:55
    • Status: offline
    • Ribbons : 0
    Re: question about 'balanced signal' on evga nu 2019/01/23 15:55:48 (permalink)
    Thanks again. Now learning about what happens when you plug a balanced signal into the unbalanced jack ;) http://www.rane.com/note110.html
    #5
    jll544
    Superclocked Member
    • Total Posts : 101
    • Reward points : 0
    • Joined: 2006/07/29 13:25:09
    • Status: offline
    • Ribbons : 9
    Re: question about 'balanced signal' on evga nu 2019/01/24 14:02:13 (permalink)
    Since we're talking about un/balanced signals... I took a closer look at the back of the card and was surprised by how long some of the unbalanced circuit traces are, especially considering there's no shielding over the back. Unfortunately, there seems to be potential for EMI noise affecting the headphone output and microphone input, as one owner experienced.
     

    Bottom line, on this card, the line-in and line-out jacks will provide the least noisy input/output.

    Attached Image(s)

    #6
    jeffswitzer
    Superclocked Member
    • Total Posts : 126
    • Reward points : 0
    • Joined: 2018/09/28 09:14:55
    • Status: offline
    • Ribbons : 0
    Re: question about 'balanced signal' on evga nu 2019/01/24 19:01:40 (permalink)
    I haven't tested the mic, but with a pair of Sennheiser HD 598SE I get no hum or hiss even when the headphone volume is cranked to 100% (no music playing). On these headphones I can't go above 50% before it's too loud. Also don't know if this matters but this is even with my PC currently plugged into an open ground outlet. If I run my finger over the metal PC case, I can feel a light buzzing sensation. Am going to eventually going to run a dedicated line but just moved into this house. The only thing I really want to input into the card is an electric bass, I'd rather go line in than mic, but most DI boxes I see output @ mic level. It's an active pickup, but even so the instrument level out lvl is too low.
    #7
    Jump to:
  • Back to Mobile