[DACLadder]

@Wynnytsky Balanced lines (differential) reduce common mode noise or employ "common mode rejection" per your diagram. The induced noise is the same phase (common) on both lines of the pair but when summed in the receive the net result of noise is near zero. The audio signal, with one side inverted, is not common and gets summed in the receiver. Audio - (- Audio) = 2 x Audio. Noise - Noise = 0. The best example of common mode noise rejection is a balanced microphone with 100 ft. of cable. The noise on the line is probably larger than the actual microphone signal but gets 'rejected' at the balanced receiver.

With single phase everything gets amplified. Other examples in the same way balanced DACs and amplifiers reject common power suppy noise and induced noises.

@Articnoise I still use the homemade I2S boards designed back in 2014. All three DACs. Kingwa was slow to adopt LVDS I2S (I2s over HDMI hardware) as he was deathly afraid of being sued by HDMI.org. No worries as all you have to state is "this interface is not HDMI protocol compatible".. HDMI.org still makes money off of cable and connector royalties.

LVDS is superior to TTL I2S as far as preserving jitter and signal quality. This was especially true when I2S Mclk was used to recover I2S audio. With asynchronous firmware Mclk is no longer used but I2S is still king on my DACs. So "garbage in, garbage out" rule still applies. But with each year and newer firmware/ technology there is less and less variation between inputs.

 

[FredA]

@Wynnytsky Not relevant. Forget the hdmi protocol and whatever they say about it. Only the cable and connector are used for i2s.

Differential pertains to inputs. When an input is differential, there can't be a ground loop involving the sender and receiver as the ground in not put in common between the two. Balanced means the signal is transmitted as itself and its inverse in two separate lines. When going to a balanced gear, the signal remains in two phases, as received. Otherwise, with some gears, the negative is subtracted from the positive and the result becomes single-ended, using a differential circuit. With other gears, only the positive phase is kept.

 

[Wynnytsky]

this is good
https://www.hairballaudio.com/blog/resources/diy-resources/balanced-and-differential

He says...
"balanced signaling" is 2 signal conductors
"differential signaling" is 2 signal conductors, with inverse polarity on the 2nd signal conductor

Then he says...
"in audio" (I guess that means analog XLR only?) the 2nd signal conductor can be 0v (which I thought was always the case before today) OR it can employ differential (ie: inverse polarity)

@DACLadder
From that, can I say differential is a specialization of balanced? (ie: differential is balanced, but not the other way around)
Thus far when CMR is used in digital transmission I'm always seeing the differential method.

 

[marcelnl]

so I think we are agreeing that I2S can be implemented in different ways, and manufacturers do not use one single method/standard.

LVDS is indeed differential, but it is just one method to transmit I2S

RJ45 and HDMi are mere conductors used to transmit the I2S signal

so IMO the conclusion that RJ45 sounds worse than HDMI is a stretch without knowing how I2S over RJ45 is implemented and hoe I2S through LVDS using HDMI is implemented. In a brief communication with the designer of Metrum he informed me that their choice for RJ45 was done for sonic reasons and that in his implementation cable impedance is critical.

 

[FredA]

so I think we are agreeing that I2S can be implemented in different ways, and manufacturers do not use one single method/standard.

LVDS is indeed differential, but it is just one method to transmit I2S

RJ45 and HDMi are mere conductors used to transmit the I2S signal

so IMO the conclusion that RJ45 sounds worse than HDMI is a stretch without knowing how I2S over RJ45 is implemented and hoe I2S through LVDS using HDMI is implemented. In a brief communication with the designer of Metrum he informed me that their choice for RJ45 was done for sonic reasons and that in his implementation cable impedance is critical.

Of course, it is implementation dependent. Inside the dac, only 4 lines are used anyway. With hdmi, there is a great choice of audiophile cables, and balanced transmission is a plus as it prevents ground loops and crosstalk to a certain extent. But there is a conversion that needs to be done at the source and another one at the destination.

So whatever sounds best in your particular context is the right choice. The hdmi is more commonly used today, so this has to be taken into account too when buying equipment.

 

[marcelnl]

Agree with you on that Fred!

 

[FredA]

I seems that fw 3.933 is the one for me. There is a trace of hardness with the others i don't have with it.

Also again, it has tremendous bass presence and extension, while sounding very organics, with very meaty timbres. Also with very good layering and depth. For me, it sounds like the original fw, i.e. analog, but a little improved. And of course stable with the ext. CLOCK

 

[Thenewguy007]

A bit confused, on the website for the Di20, it say's

CLK OUT:  Outputs 256fs main clock or LRCK/WCLK (3.3V LVDS @ 50 Ohm) . User-selectable

What does CLK OUT & LRCK/WCLK mean?
Which should be used when using the internal clock & which should be used when using a external clock?

 

[FredA]

A bit confused, on the website for the Di20, it say's

CLK OUT:  Outputs 256fs main clock or LRCK/WCLK (3.3V LVDS @ 50 Ohm) . User-selectable

What does CLK OUT & LRCK/WCLK mean?
Which should be used when using the internal clock & which should be used when using a external clock?

Does not matter. It is for the clock output.

 

[rsbrsvp]

Today is the first time I have listed to 3.933.

Bass is the best I ever heard in my system. Extremely dynamic and full with stunning resolution. This version also to my ears- sounds the most improved with my external clock as it is the combination of the external clock and the FW which is producing the incredible bass, weight and punch.

4.075 is the politeness, and soundstage king. 3.933 is the detail, punch, and bass weight king..

I agree TOTALLY- 3.933 is it for now. Could be others are better with internal but with external this FW is it...

 

[marcelnl]

I seems that fw 3.933 is the one for me. There is a trace of hardness with the others i don't have with it.

Also again, it has tremendous bass presence and extension, while sounding very organics, with very meaty timbres. Also with very good layering and depth. For me, it sounds like the original fw, i.e. analog, but a little improved. And of course stable with the ext. CLOCK

that sounds great! I'm afraid I'm going to have to audition a DI20 soon! Compare it to a souped up SU1...

 

[FredA]

that sounds great! I'm afraid I'm going to have to audition a DI20 soon! Compare it to a souped up SU1...

It’s much better than a su1 from those who had both. it is great transport AFAIAC.

 

[soundlogic]

+1 for FW 3.933, for ALL the reasons noted above. Very “analog sounding” but with all the detail, weight, soundstage etc. that we associate with the best digital. No harshness or stridency to my ears.

 

[zoophaugus]

My friend Bech had the xspdif 2 with an uptone iso regen and seperate lps which indeed sounded very good. In my opinion, the di-20 (even non HE) that he bought was a lot better: more natural sound, better instrumental sound, more detailed, more impact in the bass - simply better on all accounts.

I my system, I borrowed his xpdif2 to compare to my gustard u12, and I actually preferred the u12 - the xpdif2 had a kind of veil effect in my system which was strange because when trying the u12 in my friend‘s system, the xpdif was the clear winner.

When I borrowed the di-20, i bought one the same night!!

Thanks for the reply.. I guess what I am really asking is whether or not the DI-20 has the same strength wen it comes to Spdif input to Spdif output as it does with the Usb input to Spdif output. Is some one using it in that fashion say with a streamer for source feeding it Spdif and what do you think?

 

[Wynnytsky]

Thanks for the reply.. I guess what I am really asking is whether or not the DI-20 has the same strength wen it comes to Spdif input to Spdif output as it does with the Usb input to Spdif output. Is some one using it in that fashion say with a streamer for source feeding it Spdif and what do you think?

I'll ask my friend to bring the matrix with his MSB dac next week - i'm curious as well