SPDIF transformer and signal quality.

[counter culture]

I'll make a mental note to ask for clarification next time I encounter you using the same confusing word in future 🙂

Can't see the 'wood' for the trees, eh?

 

[Eldam]

Thanks Storm & Abrax,

Ok the Murata will stay in the museum parts on the shelves !



And this one for 16/96 Khz DACs : Mouser Electronics, Inc. : this one is good for multibit DAC and spidf (AD1862, TDA1541 )

Many advised me the famous Newava around 6 dollars but only Digikey have it not Mouser ! I have to try for my next buy this supplier. Here this thetwo less expensive ! Farnell or others are not cheap !

As I have two SB Duet & two Subbu (still no scope tool & the knowledge to use it), I would like my ears decide andf check again this thread after to understand subjectivly the qualities & defaults in this particular try (SB + Subbu). Well the ES9023 is not a multibitDAC... so the Newava maybe !

Add 2 or 3 years ago a AD1865 DAC from Raindrop Hui with "bad" parts : and as said Lampizator : tha gain of SQ & transparence without the spidf chocke was huge... (I understand since the man is not really a specialist of RF & digital, more a old school tubes one...).

Well I just realise than USB to I2S lines don't use transformers but isolator chips to break the ground loop & noise !

 

[AR2]

Why would a trafo built into a PCB have lower interwinding capacitance than one wound on a core? ISTM that a planar trafo would be likely to have more capacitance, not less as it'll have more common surface area between windings when the windings are flat. Also aren't you pretty much stuck with FR4 as the insulator? Wikipedia says FR4's epsilon is 4.8, seems rather high when you want to reduce interwinding capacitance. As a reference there are trafos by Scientific Conversions that achieve capacitances of the order of 1pF - see here:

Scientific Conversion, Inc. - Transformers and Inductors

Not that I use these as they're a bit on the dear side.

+1
I use these, and Jon who owns SC is real and rare expert on digital signals transmission. He had some really good papers on digital transmissions and digital transformers. Check for his papers published for AES conferences. They are a great reading material. To also make things clear, we think a lot in the terms of home use and DIY environment. In broadcast environment with miles and miles of installed cabling these transformers shine and are a must. Compared to that, one S/PDIF line of 1 m is much less demanding or problematic. Certainly, proper transmission, matching and termination should be norm we always follow.

 

[Julf]

In broadcast environment with miles and miles of installed cabling these transformers shine and are a must. Compared to that, one S/PDIF line of 1 m is much less demanding or problematic.

Indeed, the typical operating requirements of most pro systems and installations would give the typical OCD audiophile some rather sleepless nights 🙂

 

[Eldam]

My line is full 75 ohms (but the pcbs lines ?) and 15 cm.... very short !

 

[marce]

Indeed, the typical operating requirements of most pro systems and installations would give the typical OCD audiophile some rather sleepless nights 🙂

As would many non audio based set ups and installations...and why differential signalling is the preferred choice these days.

 

[Julf]

differential signalling is the preferred choice these days.

+1

 

[Eldam]

You mean symetric pro audio 3 pins conections ? Does they not use also traffos everywhere : mic line, analog line, digital line ?

 

[Julf]

You mean symetric pro audio 3 pins conections ?

Connectors are not the essential part (but yes, usually symmetric *audio* cables use 3-pin XLR connectors). The essential part is differential, balanced signalling and differential input stages - giving immunity to common mode noise and interference. Most noise and interference is common mode.

Does they not use also traffos everywhere : mic line, analog line, digital line ?

Not necessarily. Transformers are one way of doing it, but a differential (op-amp-style) inputs and a differential/balanced output stages don't require transformers.

 

[marce]

You can use a balanced line (or balanced routing) with a single ended signal and gain many benefits, but a differential signal with balanced routing (PCB, cable) gives the best common mode noise rejection.

 

[elektryk]

Sorry for the long break but I have received PE-65612NL from ebay and connected it to my DAC, for me it didn't worsen the audible quality of 44.1kHz/16bit signal and obviously brought ground loop (its easy to hear it when the volume is at a maximum).

My DAC is currently based on CS8416+AD1852+second order active filter, some noise is audible at maximum volume and paused music but its irrelevant during normal hearing.