Optical Toslink.

In the hifi world, as far as I can make out, SPDIF optical toslink is considered inferior to SPDIF coaxial. Is this fair, and, if so, is Toslink still inferior for transferring a 2-channel digital audio signal to a computer for recording?

 

spdif requires 2 extra conversion stages (electrical to optical and back) which is done as cheaply as possible most of the time. also most optical cables are inferior plastic and not glass. both of these reasons see optical considered as the poor relation to co-ax spdif.
there is another optical connection (at&t st glass) which is supposed to be the bollocks but it's a bit esoteric and usually only found on stuff like wadia's spinners.
if optical spdif is the only option then fair enough but if youhave electrical spdif on both bits of kit then i'd use that.

 

Thanks

Are there any 'superior' quality optical cables for out there?

One good thing I heard about optical when recording to a computer is that it separates the unit (e.g. AD converter) electrically from the computer. This is considered an advantage in the computer audio world. Firewire or USB is not electrically isolated and doesnt transmit a clock signal. Not sure about Coaxial, though.

 

Yes .....but don't ask me which, but go for glass rather than plastic optical fibre.

I only use optical for my dab ..as it hums something rotten if connected via coax to my dac.

Differences are there but its acceptable with dab as that compromised in many other ways for me. But 5live still sounds better than the am reception.

 

Computers are complete RFI nightmares. Whilst each component within a computer will pass CISPR13 and FCC part 15 class 2 requirements in isolation, when you put them all together in a box with large holes in it (in RF terms) it would not pass the required standards.

If you put an electrical connection from a computer to your hifi, you've just given a conduit for that EMI straight into the hifi. With optical, that is not the case.

In the case of two well-behaved pieces of equipment (eg a CD player and a DAC) then typically the much lower jitter of the coax interface is preferable.

Try it, listen to it, choose what works best for you.

 

Cheers.

From what you are saying, I was right in thinking that optical or adat was the way to go, as I have a high quality standalone AD/DA converter next to the hifi with the computer about 2.5 metres away. For the same reason, an SPDIF coaxial, USB or firewire connection would not be ideal, especially when all cables (between hifi/converter and converter/computer) are left permanently connected.

 

Baudrillard, I love your signature...

 

Thanks Garmt :MILD:

Crackin system you've got there!

 

TWO cracking systems, by the looks of it

You have ML Clarity on surround duties?! Some would call that overkill

Don't forget that you need to put some money aside to eat once in a while.....

DT

 

Does using the TOSlink cause data errors or is it possibly just a jitter issue? If it's the latter does this matter at the recording stage? (It will for the initial ADC stage but once in digital form, and assuming it's being recorded digitally, naively I have thought it might not matter at all?)

 

That's a good point martin... Where the ADC must have its own sample clock and jitter is critical at that point, for transfer from there to the computer where it can only remain in the digital domain, jitter is irrelevant as long as it is not large enough to cause bit errors (ie what you said).

Going the other way it may not be true, depending on whether the data is reclocked to the internal clock of the DAC/ADC or derived from the input data.

 

Thanks!

 

Yep. Separate rooms.

Ah, well...

That money is normally taken by my girlfriend...

 

Staying with my example of using an ADC next to the hifi with the computer several feet away- connected preferably by optical cable to a PCI card at the computer end. The high quality ADC will do its own stable clocking, remove jitter and take permanent care of optimal conversion quality.

But is it important to have a high-quality PCI device at the computer end? To the best of my knowledge, all but the very cheapest of PCI cards (or other SPDIF/firewire interfaces) will not resample the digital signal on its way to the hard drive (I think!). However, might the circuitry in a still cheapish PCI card degrade the signal in some other way, thereby compromising the good work done by the original AD converter? Would it be wiser to get a PCI card of similar quality to the AD converter?

In my case, do I need to mate the standalone RME AD converter to an RME PCI Card (even though I will be wasting money on the redundant converters of the latter.

Sorry to ramble on but I want to get it right- and opinions in the pro-audio world seem to vary on this point .