[Wynnytsky]

I emailed Kingwa this morning and just now got a response
I doctored it up to look like a head-fi interaction

Q: [In your balanced DACs] is "common mode rejection" applied first in the differential receiver of the USB/I2S inputs, and then again at the XLR/ACSS outputs?

The HDMI input module receive the differential signal and conversionn to single ended signal, most audio brannds DAC / source HDMI-IIS transmit work with this mode for avoid the signal effect by transmit. And the USB , even though there are some different brands in world but all work in same mode to get the USB signal. Nothing is particular .

Q: are all/any audio-gd DACs fully balanced (2 signal lines along the entire analog circuit)?

All our on sale DACs except R2R11 , though some models with only single ended output like NFB11, but the DA feed to analog parts with balanced signal.

Q: which "balanced" does audio-gd use on the second signal line? 0volt or inverse polarity?

0V signal not balanced. balanced must has the positive signal and the exact inverted negative signal gain and output. You can search in our web, the products mark real balanced on top side, it must work in real balanced mode.

the takeaway is the entire analog path runs in symmetric balanced

 

[FredA]

We all got that differential, symmetric and balanced are 3 different things.

Now the impedance is not matched during transition? Not true according to this article. True otherwise of an i2s transmission using TTL or LVTTL, which are single-ended.

https://en.m.wikipedia.org/wiki/Low-voltage_differential_signaling

Lvds allows fast signaling over a distance and for it to work optimally, impedance matching is required. Impedance matching will not be perfect at all frequencies of course, this is not possible. A compromise has to be made with this regard in my understanding so upper harmonics of the signal will be reflected in part. But the two phases of the transmission will stay symmetric.

So calling LVDS balanced seems legitimate.

This reference from Analog Device does refer to is as being balanced

https://www.google.com/url?sa=t&sou...FjAjegQIAxAB&usg=AOvVaw3S6te117Vwhn0YeQchVIC3

 

[FredA]

Frankly, i don't care as LVDS i2s with 3.933 and the external clock sound freaking well. Life is good when i listen to music.

 

[FredA]

One thing Kingwa mentioned at some point is that his balanced preamps will convert an incoming single-ended signal to a balanced one so that it can benefit from the balanced implementation.

Kingwa is a die-hard old school audiophile and designer but with fresh ideas to improve on these old designs.

Non-feedback power amplifiers is a good example. 99.999% of power amps use feedback today. Kingwa does not on his top amps. The result i can hear is high-frequency response free of hardness or glare, yet transparent enough to let you hear any glare from upstream. Kingwa decided on purpose to implement an amp with an even 0.08% distorsion up to 5k so that timbres stay cohesive whathever the pitch. And from there to 20k the treble rolls off to allow those sweet highs. This is innovation. Also important is the fact that these figure remain when you raise the volume, so the amp stays composed when pushed. Frankly, this amp takes forever to burn in and requires proper cable matching but it performs extremely well.

 

[DACLadder]

Jeez, let’s move on.

 

[sajunky]

We all got that differential, symmetric and balanced are 3 different things.

Now the impedance is not matched during transition? Not true according to this article. True otherwise of an i2s transmission using TTL or LVTTL, which are single-ended.

https://en.m.wikipedia.org/wiki/Low-voltage_differential_signaling

Lvds allows fast signaling over a distance and for it to work optimally, impedance matching is required. Impedance matching will not be perfect at all frequencies of course, this is not possible. A compromise has to be made with this regard in my understanding so upper harmonics of the signal will be reflected in part. But the two phases of the transmission will stay symmetric.

So calling LVDS balanced seems legitimate.

This reference from Analog Device does refer to is as being balanced

https://www.google.com/url?sa=t&sou...FjAjegQIAxAB&usg=AOvVaw3S6te117Vwhn0YeQchVIC3

You are wrong again. I decline to comment on your inpretetation of Wikipedia to not waste other members time. A linked National Semiconductors document AN-1382-6 do not call LVDS a balanced connection either, nobody does, period. They say in one place "Therefore, it is important to maintain a balanced and closely-coupled differential transmission path", so they try, but it is not possible to maintain balancing during transition period as I wrote already. It is why LVDS name is a short form of "Low Voltage Differential Signaling", not a LVBS. The other things that may keep you confused is a fact that there is a talk about DC balance. This is about data encoding, complete different things.

TL;DR, Pay respect to the naming convention and stop calling LVDS balanced and continue this endless dispute in the wrong thread. You can be confused, but you mustn't confuse others.

 

[FredA]

0

You are wrong again. I decline to comment on your inpretetation of Wikipedia to not waste other members time. A linked National Semiconductors document AN-1382-6 do not call LVDS a balanced connection either, nobody does, period. They say in one place "Therefore, it is important to maintain a balanced and closely-coupled differential transmission path", so they try, but it is not possible to maintain balancing during transition period as I wrote already. It is why LVDS name is a short form of "Low Voltage Differential Signaling", not a LVBS. The other things that may keep you confused is a fact that there is a talk about DC balance. This is about data encoding, complete different things.

TL;DR, Pay respect to the naming convention and stop calling LVDS balanced and continue this endless dispute in the wrong thread. You can be confused, but you mustn't confuse others.

Frankly, you possibly are right, the NS document (not AD) uses the balanced but not necessarilly with the meaning you associate to it, not sure, i don't care so much. But the audience here is composed of adults. And my friend @DACLadder, who designed the HDMI i2s module for audio-gd, calls it balanced. So i am naturally inclined to think he is right.

You can comment or not on my interpretation of wikipedia's article. I am not totally assertive expressing it. I may or may be 100% right. LVDS is as close as the idea of balanced as digital signaling can be. Some authority may decide to call it balanced digital signaling eventually, and I would not call it misleading. Is there a formal definition published by IEEE?

To people who care and with sufficent background, do the research. Now i will continue to post whatever i want and try to stay on topic a little more. I want no bad to anyone. We are audiophiles here, first and foremost. And this discussion is meant for engineers. So we should call it off. Or send me PMs. I am always willing to learn.

At least, i think we could agree that LVDS is a great idea for i2s.

 

[Wynnytsky]

@FredA you aren't interested in people learning the truth -- only that it comes from your words, and with each human mistake you just cover it over with your frankly, not necessarily, naturally inclined, my interpretation, not totally, may or may not, some may decide, not call it misleading. The only truth in that post is "I will continue to post whatever I want". What an ugly read.

 

[DACLadder]

@sajunky Please stop lecturing us. From the National Semiconductor AN-1386-6 document (LVDS) it states on page 7. " Balanced differential lines have equal but opposite currents, called odd-mode signals... Therefore, it is important to maintain a balanced and closely-coupled differential transmission path to reduce emission of electromagnetic interference.".
http://literature.cdn.keysight.com/litweb/pdf/5988-4797EN.pdf

You are clinging to an old term of 'balanced' that was inferred 50 yrs. ago exclusively for XLR analog connections.

 

[FredA]

@FredA you aren't interested in people learning the truth -- only that it comes from your words, and with each human mistake you just cover it over with your frankly, not necessarily, naturally inclined, my interpretation, not totally, may or may not, some may decide, not call it misleading. The only truth in that post is "I will continue to post whatever I want". What an ugly read.

I am just being myself and giving my opinion, for what it's worth. You are allowed not like me or what i am saying. Or not. We are all human, with strengths and weaknesses Putting labels on things is not not my thing as language is also a matter of context. I say this before God: i hope to be honest everyday that i live and to remain humble., forgiving and open-minded, assuming i am. And to be happy in the process. Is this the C19 craze that's making us behave like this? I may have a character flaw or two, but as said, we all do. Thanks for maybe pointing one of mine. Have a nice day, my friend.

 

[sajunky]

Lets stick to a name "Differential", the name LVDS is indicative. Don't try to rename to the LVBS. It is perhaps a time moderators should come up and clean this rubbish, as participants clearly declared they were not going to stop speading their own theories. If you want to argue, open dedicated thread to your "Balanced" interpretation.

 

[DACLadder]

Call it what you want but the LVDS interface is still balanced. That is not a proper name but physical characteristic. Sorry your are confused on the term and suggest you stop spreading your BS.

I apologize to the forum members. I will not respond further to this topic and will be more than happy communicate with the moderators.

 

[tumpux]

Dont worry, most of us will just scroll down and ignore these lengthy debates.

 

[Articnoise]

Everyone has the right to debate, regardless of who is right or wrong, but attacks and personal attacks are not allowed here. Stop it and stick to discussing hifi stuff and how it sounds and works!

 

[JaMo]

Everyone has the right to debate, regardless of who is right or wrong, but attacks and personal attacks are not allowed here. Stop it and stick to discussing hifi stuff and how it sounds and works!

+1