Why is SPDIF better than USB?

[joe_cool]

Quote:

If the I2S converter output were in the design of the DAC chip, you wouldn't have to worry about as much interference?

The DAC chip has I2S input. Maybe you mean the SPDIF-to-I2S converter being in the DAC. Someone inferred this would eliminate "all this circuitry" but I don't see how.

 

[middachten]

Quote:

If the I2S converter output were in the design of the DAC chip, you wouldn't have to worry about as much interference?

Not sure what you mean here?
 

 

[Happy Camper]

Design a DAC chip with the USB/I2S interface incorporated.

 

[middachten]

Quote:

Design a DAC chip with the USB/I2S interface incorporated.

 
This could help, but still one would need a stable clock/re-clock mechanism to feed the DAC part with the right (and low-jitter) timing. There is no such thing as Bit Clock or Word Clock within the USB part of the signal flow.
 
In other words, you need a buffer+re-clocking mechanism to deal with the asynchronous nature of the USB standard (not to be mixed with the discussion of sync/async audio streaming over USB, thats the software implementation part of it). All the chips I mentioned in my earlier post do this one way or the other.
 
BTW there are various USB-DAC chips that do exactly what you suggest. But devices(such as the Burr Brown/Ti PCM 290x series do not exactly prove that this can result in better quality results

 

 

[SkyKidFalken]

Is toslink better than usb and spdif if connect amp/dac to  a desktop computer
 
thank you

 

[grokit]

Toslink (optical fiber) is arguably the worst of the three forms of s/pdif, the other two being coaxial and BNC. "Adaptive" USB is generally known to be of inferior audio quality to s/pdif but other implementations of USB reportedly have better potential. All computers have USB, and some also have toslink digital audio output which is more of a consumer audio standard.

 

[middachten]

Toslink is indeed one of the worst solutions from a jitter perspective. Considering the sloppy mechanics its a wonder that it actually works.... There are much better optical solutions, but these where to expensive to implement when this standard was set in the eighties of last century (sounds like a looong time ago).
 
There is a benefit to optical connections: galvanic isolation. Which means as much as: keep all the dirty noise of one piece of equipment (computer) isolated from another piece (DAC).
 
IF you have a good optical cable, clean connector ends and IF you have a good jitter reduction strategy in place, then it could work quite well. But those are very big IFs that are harder to fulfill than making a good coax connection (with BNC or RCA plugs)

 
Quote:

Is toslink better than usb and spdif if connect amp/dac to  a desktop computer
 
thank you

 

[haloxt]

Although I think coax sounds technically superior, I keep going back to optical of my h120 mp3 player because the background seems darker and less fatiguing than the coax spdif of similarly cheap transports. I still like to switch between different digital outputs for different sounds though, even when going through a $500 reclocker.

 

[SkyKidFalken]

should i use spdif instead of usb and toslink?
 
my sound card has both Toslink and SPDIF
 
 
 

 

[MacedonianHero]

Quote:

should i use spdif instead of usb and toslink?
 
my sound card has both Toslink and SPDIF
 
 
 

Order of preference: SPDIF > TOSLINK > USB

 

[zenpunk]

There shouldn't be any difference between Coax and Optical those days. Both Coax and toslink are identical (SPDIF). The only difference is one resistor and one diode in series (voltage ON/ light ON- Voltage OFF/ Light OFF).

 

[K3cT]

Well, I'm currently borrowing a Musiland 01 USD from a friend along with a Stax rig (404LE and SRM-1/MK-2) and I'm having a really difficult time telling apart the sounds from USB, optical and coaxial from my Gamma2 DAC with that rig. Perhaps I can surmise that the link Jude posted a few pages back, where engineers conclude that 'implementation is key', ring truer than ever. 
 
So my conclusion? S/PDIF is not necessarily better than USB.

 

[upstateguy]

Quote:

There shouldn't be any difference between Coax and Optical those days. Both Coax and toslink are identical (SPDIF). The only difference is one resistor and one diode in series (voltage ON/ light ON- Voltage OFF/ Light OFF).

I didn't know that.  Are you sure?
 
I thought there was a lot of jitter on Toslink?
 
USG

 

[grokit]

 
Quote:

should i use spdif instead of usb and toslink?
 
my sound card has both Toslink and SPDIF

 
Quote:

Toslink (optical fiber) is arguably the worst of the three forms of s/pdif, the other two being coaxial and BNC. "Adaptive" USB is generally known to be of inferior audio quality to s/pdif but other implementations of USB reportedly have better potential. All computers have USB, and some also have toslink digital audio output which is more of a consumer audio standard.

 
In case that wasn't clear, toslink is a form of spdif  

 

[Epoch]

Quote:

Well, I'm currently borrowing a Musiland 01 USD from a friend along with a Stax rig (404LE and SRM-1/MK-2) and I'm having a really difficult time telling apart the sounds from USB, optical and coaxial from my Gamma2 DAC with that rig. Perhaps I can surmise that the link Jude posted a few pages back, where engineers conclude that 'implementation is key', ring truer than ever. 
 
So my conclusion? S/PDIF is not necessarily better than USB.

 
I believe that your inability to clearly distinguish between the input methods is due to the use of an ASRC chip on the Gamma2, which according to whitepapers on that type of device is supposed to minimize/eliminate jitter.
 
Here is a short and easy to read article by Benchmark about using an ASRC
http://www.benchmarkmedia.com/discuss/feedback/newsletter/2010/05/1/jitter-reduction-using-pll-and-asrc-devices