USB -> V-Link 192 -> Coaxial -> Audio-gd Ref 5.32
I love the V-Link. And it is $200 currently.
Took 100 hours to burn-in.
Edited by PeterCraig - 1/14/13 at 3:22pm
It's a matter of implementation. Many DACs have USB inputs inferior to the other inputs. Other DACs have great USB inputs.
Most USB inputs convert USB to S/PDIF internally anyway. An external converter might possibly do a better job.
I've been playing around for a while with this and the best I've experienced so far is my iPad streaming audio through an Audiphilleo 1 with Pure Power supply via a Vaunix Hub (otherwise the iPad says that the AP1 draws too much power). I'm not sure if it is better than just using my MacBook Air to the AP1, but it does sound different, at least on high-res files, which is very annoying!
PC/Mac >USB >Dac (MF VDacII) Here's why.
By using the USB connection to the dac you are bypassing the internal circuitry of the computer soundcard and it's noise/limitations.
SPDIF is the output of a soundcard/Motherboard and is therefore subjected to the aforementioned noise etc.
You would use a USB to spdif converter if your dac did not have a direct USB input.
Incidentally - SPDIF (Sony, Phillips Digital Interface) is the means of transporting digital audio using an RCA type connection.
It is not internal as has been mentioned in this thread but simply the name of the physical Jack you'd connect the cable to.
I always make sure any motherboard I purchase includes an optical S/PDIF (Toslink) connector. This eliminates any chance of noise from ground loops. I build my own computers and upgrade components very frequently, and even the slightest background hum drives me crazy, so I go completely optical whenever I can for all of my audio solutions.
Really? This is a fact?
The people from iFi told me they do not use SPDIF as it is high jitter (whatever that is anyway)? Have I been told porkies?
Maybe I'm being pedantic here but Toslink and spdif are not the same thing.
SPDIF is a type of Digital audio connection point using RCA jacks.
The Digital audio connector type for Optical Audio cables is called Toslink.
The two are not the same.
"There also an optical version of S/PDIF interface which is usually called Toslink, because uses Toslink optical components. The transmission media is 1 mm plastic fiber and the signals are trasmitted using visible light (red transmitting LED). The optical signals have exactly the same format as the electrical S/PDIF signals, they are just converted to light signals (light on/off). Because high light signal attenuation in the Toslink fiberoptic cable, the transmission distance available using this technique is less than 10 meters (with some equipments only few meters)."
A lot of people will discuss the capabilities of the USB or digital receiver chip from companies like Tenor or Cirrus Logic. As Currawong mentioned (and can probably explain in better detail!), these receiver chips will take a signal from an input (USB) and convert it to I2S or S/PDIF for processing by the DAC. One example I found for the Tenor TE7022L shows some common applications include USB to SPDIF or USB to I2S. Of course this can vary widely and may not be how iFi "does it" either...
Sorry mate, but this went right over my head.
I have been told USB does not have the problems with something called jitter the way SPDIF does.
I remember when I bought my Naim CDS CD-Player it had all electronics in one box and the power supply in the other. Naim said that was because "SPDIF is bad", most decent CD stuff at was 2-box with SPDIF and I did not like the way it sounded. So Naim did 2-Box but differently. I really liked and still like the way it sounds.
So I get Jitter = Bad and SPDIF = Bad. And I'm thus easy to sell on "SPDIF bad, USB good", sort of like "2 legs bad 4 legs good".
I have no idea about all that other stuff.
What I'm now worrying have I been told figs?
If I understand Currawong right he says that all the USB inputs on DAC's use SPDIF anyway, just not outside with a cable?
Is that right?
And if so all that talk about "USB good and SPDIF bad" would seem an utter load of tosh?
I don't like being told porkies. Maybe I'll e-mail iFi, see what they say...
there are 3 different ways a usb receiver may get its audio data from the pc: synchron, adaptiv and asynchron
here is a good writeup by Christiaan Puunter:
synchron (not used any more, clock-timing based on the usb timing)
adaptiv (normal mode today, clock timing more or less based on computer clock by recalculation of timing of incoming data)
asynchron (clock timing totaly based on clock chip in the usb receiver, receiver stores usb data and makes reclocking with own clock chip)
... so synchron and adaptiv mode tend to have jitter problems (working with computer clocks is not very "stable in timing"), asynchron mode should not (or the clock chip is bad)