[DACLadder]

Your definition of balanced is archaic. What is not analog about a signal on a wire? Any signal. All digital interfaces (except undefined TTL I2S) have characteristic impedances which are analog domain properties.

 

[marcelnl]

No offense intended; I vote for sticking to proper terminology as things can get confusing real fast when we have to guess who is using what definition for differential/balanced and whatnot.

From wat I read LVDS (which was the topic) is truly different from balanced; source wikipedia:

LVDS is a differential signaling system, meaning that it transmits information as the difference between the voltages on a pair of wires; the two wire voltages are compared at the receiver. In a typical implementation, the transmitter injects a constant current of 3.5 mA into the wires, with the direction of current determining the digital logic level. The current passes through a termination resistor of about 100 to 120 ohms (matched to the cable's characteristic impedance to reduce reflections) at the receiving end, and then returns in the opposite direction via the other wire. From Ohm's law, the voltage difference across the resistor is therefore about 350 mV. The receiver senses the polarity of this voltage to determine the logic level.

 

[DACLadder]

LVDS is indeed balanced line. There is equal but opposite polarity current on the 2nd wire of the pair. LVDS receivers have CMRR.
Give us an example of unbalanced differential signaling - analog or digital?

 

[FredA]

Wikipedia is not the Bible on any subject. Especially for those who wish to learn what happened on a specific day of 2001.

This said, there is no issue calling it balanced from this other wikipedia article, which goes along with what Scott (@DACLadder ) said:

https://en.wikipedia.org/wiki/Balanced_line

 

[Wynnytsky]

Especially for those who wish to learn what happened on a specific day of 2001.

we're safe so long as the revisionist historians are incapable of contributing to those STEM articles.

when seeking the truth the onus is on us to determine which sources that have it vs those who think they have it, or worst of all, those who consciously swap the truth for something they like better (MSM!)

 

[DACLadder]

The last paragraph of the Wiki article is a little misleading and strikes a conclusion that differential is not necessarily balanced (true). But all the digital differential we use in audio are balanced. They have to be to work properly.
XLR can have many interpretations as mentioned by @Wynnytsky. Mostly to cheap out and save money. Kingwa does employ proper balancing on AGDs equipment.

 

[Articnoise]

When we talk about balanced transmission, we are actually referring to differential signalling using balanced lines. Academically, there can be a difference between a transmission using balanced lines and differential signalling, but the term balanced is commonly used to describe both.

https://www.naimaudio.com/sites/def...ownloads/files/ND 555 White Paper Final_0.pdf

 

[Wynnytsky]

@DACLadder

I understood differential to always put pin1's antiphase on pin2
(I'm calling it antiphase, but I'm seeing the terms "inverted polarity" and "symmetric" used as well)

I understood balanced audio can be implemented with 0v on pin2 or pin1's antiphase on pin2

With 0v on pin2, the cleaned signal == pin1 - pin2
With antiphase on pin2, the cleaned signal == pin1 - (pin1+pin2)/2

Assuming the former is easier to implement, I was wondering why you'd go with the 2nd, and that last paragraph gave me my answer

Symmetric differential signals exist to prevent interference to other circuits - the electromagnetic fields are canceled out by the equal and opposite currents

 

[jase01]

Just received from Larry. Not ideal. Beware all who like me own an HDPlex power supply. Rather concerning. I have a friend who recently lost his JCat XE and Net cards through his older 400w HDPlex catching fire (literally smoke and flames):


Please do NOT use Adjustable Rail A and 12V fixed XLR output together


Hi,
Thanks for purchasing 300W Linear PSU.

Please do NOT use the Adjustable Rail A and 12V Fixed Rail output together and this combination might damage your 300W LPSU.

Larry

On Thu, Oct 8, 2020 at 9:15 PM HDPLEX Support <order@hdplex.com> wrote:

 

[DACLadder]

@Wynnytsky Another way of looking at the complimentary signal on pin 3 (-) is that it cancels the magnetic field of the primary signal (+) on pin 2. Lower radiated emissions. Pin1 is the XLR shield so we have no argument.

But connecting a signal to the (+) pin only and grounding (-) is common. The line is no longer balanced but usually works fine if treat like any other single ended connection. Short cables, shielding...

Since you mentioned previously the MSB Analog DAC is single ended. Their XLR output just uses an opamp to generate the complimentary signal to drive the XLR. As a result the single ended output sounded better. At least was so on the unit I had 5 yrs ago. Something to check out if you audition this DAC.

 

[Wynnytsky]

@DACLadder yup it's the same MSB from 2014 -- but with their latest usb/coax/fw. The shootout with my 2017 agd will be on pay-per-view

@jase01 Larry said the issue doesn't apply to the 200w. Is the P8 within your budget?

 

[FredA]

@DACLadder yup it's the same MSB from 2014 -- but with their latest usb/coax/fw. The shootout with my 2017 agd will be on pay-per-view

How much? A nice host lady would be welcome, with the fake pandemic, i miss my lady friends at the office.... My buddies too now that i think about it.

Just received from Larry. Not ideal. Beware all who like me own an HDPlex power supply. Rather concerning. I have a friend who recently lost his JCat XE and Net cards through his older 400w HDPlex catching fire (literally smoke and flames):

Not the sort of fire you roast marshmallows over unfortunately...

 

[zoophaugus]

Yes and no.

The process is not the exact same, the output signal only needs to be clocked with the usb in, because with asynch usb, it is possible to avoid reclocking. So this means lower jitter at the output of the di20 for usb. For this to be possible, the amanero usb board takes its timing from the fpga, therefore the same clock drives the usb module and the output signals. This is the best possible approach IMO for a usb to spdif/i2s converter.

With the spdif input, the signal absolutely needs reclocking. So in theory, usb will sound better. But sound quality still depends on the incoming signal quality, and i can testify that my usbridge sound better then a rpi4b+.

I did an a/b between the output of my oppo dvd drive directly to my r7he, and through the di20he. The sound quality improvement is major through the di20he. It makes home cinema (2ch only) much more enjoyable.

Excellent,
That's the kind of info I was looking for.

 

[Mix80]

Please do NOT use the Adjustable Rail A and 12V Fixed Rail output together and this combination might damage your 300W LPSU.

@jase01 Larry said the issue doesn't apply to the 200w.

I was suddenly lucky... Thank you for the info.

 

[sajunky]

The last paragraph of the Wiki article is a little misleading and strikes a conclusion that differential is not necessarily balanced (true). But all the digital differential we use in audio are balanced. They have to be to work properly.

Wikipedia is not misleading. I made a wrong statement saying that balanced is always diferential, it was wrong. It is true in audio where "Balanced" is also "Differential" and my mistake didn't change a merit what I was calling for.

On the other side a digital "differential" line cannot be called "balanced". A reason is because impedance matching is not maintained during transition time. Depends on a signaling clock rate it can be even 30% of time when impedance is completely uncontrolled. So please do not call digital connection like I2S "Balanced", as it is wrong. A quote from the Wikipedia link you are refering to:

Lines carrying symmetric signals (those with equal but opposite voltages to ground on each leg) are often incorrectly referred to as "balanced", but this is actually differential signaling. Balanced lines and differential signaling are often used together, but they are not the same thing. Differential signalling does not make a line balanced, nor does noise rejection in balanced cables require differential signalling.