USB or Toslink for my Audiolab M-DAC? That is the ultimate question!
Bits are bits - go with what's practical and cheap.Your bits will get there, in order and intact, before being reclocked locally.
Different transmission standards exist for different reasons.AES/EBU is the same as SPDIF digitally but the cables are designed for professional/studio situations involving potentially long runs.The AES/EBU connections are either 110ohm STP with XLR connectors for runs up to 100m (who's gonna do that at home?) or 75ohm co-ax with BNC up to 1000m (again, pointless at home).Not to mention not much domestic equipment includes digital XLR or BNC connectors.SPDIF co-ax on RCA connectors works at a slightly lower voltage (non-issue) and slightly different frame header protocols, but that's it.They both carry the same data reliably from A to B.The differences are engineering differences, and exist for practical reasons.
Toslink is an optical standard using a fibreoptic cable with standardised EIAJ JIS F05 connectors.They have a maximum useful distance of 5 to 10ms due to attenuation.Introduced by Toshiba, hence the name, for its consumer CDPs and receivers; now a widely supported industry standard.Carries data encoded in the SPDIF format.Prevents ground loops and RF interference.As such, for domestic use, the most logical option as well as probably the cheapest.
"quality" is a non-issue invented by audiophools who believe every 'difference' must be audible and distinguishable (what real audiophile would dare admit they couldn't "tell the difference" - there's ALWAYS a difference...!) and jitter is a function of the transmitting and receiving circuits in the components, and not an issue of the cable itself.Cables do NOT cause jitter!
Really, why on earth in the 21st century are people still worrying about *cables*???Don't. They work, they're cheap, they work.Choose the right cable for your application, plug the damn thing in, enjoy the music.That's all there is to it data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
USB is an almost universal PC connector standard, probably far more common than any optical or RCA digital output on PCs.External devices support USB for the simple reason it's the broadest market base to sell to.USB devices can be plugged into any PC out there, and only require a fairly standardised software driver to work. Non-PC USB devices will have their own internal, custom software and it may not necessarily sync with the DAC if they're not intended to transmit audio data.USB is a packetised serial bus, however its bandwidth greatly (USB1.1), massively (USB2.0) or mindboggingly (USB3.0) exceeds the modest requirements of Red Book audio or even 24/192 "hi res" audio.As such, unless your USB DAC is sharing USB packet space with HDDs, digital cameras, printers, etc all blasting out data via some ghastly passive hub, you simply will not ever have issues with audio data flow.Synchronous vs Asynchronous only matters if your cheapass DAC clocks off the USB...Any DAC worthy of the name has an internal clock and will FIFO buffer the data from the USB bus.USB also carries power of course, and some external USB DACs will use this power.It is likely to be noisy if the PC motherboard's power grid isn't well regulated.Independently powered USB DACs needn't connect the power pins in the USB plugs, providing isolation from the PC's potential power noise.
In short, the USB interface will work fine and exists to enable the broadest possible range of connectable computers and thus the greatest market to sell to.EVERY PC on earth these days has a USB port.Any reasonably well designed and modestly priced USB DAC will avoid the obvious pitfalls of relying on the USB clock and power rails, assuming you worry about these things.Some of course are just meant as products of convenience for casual 'desktop' users on microbudgets and DO rely on these, and that's a perfectly ok design solution, that USB offers on purpose.
After some experimenting I've found the Optical cable the best option for connecting my Audiolab M-Dac to my Mac mini. Using the usb my Mac often got confused with what it was connected to and the midi settings kept changing. Using optical it's been flawless, and gapless playback works whereas with usb it didn't.
I'd also running been running BitPerfect with both methods.
My expensive award winning usb cable made no difference!
Has anyone had any success with 192Khz using optical and the M-Dac? I've read that it's not specified but will work.
As long as the transmitter and receiver both support it, optical will carry the extra bandwidth; however you might find the limit will be the length of cable - maybe 2m or 3m rather than the 5-10m for 24/48.It is, after all, merely a transmission medium.
Anyway, if you can, give it a try data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
My girlfriends buying me a cambridge audio dac magic plus tommorow for my birthday to use with my pc and sennheiser hd595's. Do people recommend using usb or should i use the optical output from my xfi soundcard for best results?
Its hard to say . . . USB usually has less jitter than SPDIF but, depending on the implementation, may sound worse for other reasons.The best thing to do is listen for yourself.Don't expect a major difference, it will be subtle if anything at all.
Snap! I bought the irDAC this week to take the audio from my new BT Youview UHD box, the bonus being that it also has inputs for my SkyHD box, Panasonic plasma TV,computer and old DMR-BS750 BD recorder. Analogue outputs from the irDAC and my old tuner connect into my 20 year old Arcam av amp.
As you said, it has taken the sound into a new league, I wish I'd gone digital years ago!
Edit:didn't realise this was a sticky
Lots to process here and my brain hurts. I'm going from my Oppo BDP-83 to my DAC (Schiit Modi 2 Uber) via Optical then out to my receiver.
The Oppo optical signal can be set to LPCM or BITSTREAM, both work (e.g. I can hear something through the DAC!) but what's the difference?
Is one preferable?
Thanks and sorry if this has been answered 300 times above.