opinions on optical out sound

I've been playing around with my vaio f sound, feeding stereo. Turning off all the vaio sound effects, it seems OK. Doesn't blow me away, but OK. Have not done a head-to-head cd comparison yet.

Question is, how good is optical out vs. the headphone jack... feeding a sound system. On the audiophile scale, I am probably an 85% - not a $20k stereo guy, but former musician with a good ear. Will I notice the difference?

Question #2: Is there an add-on sound card that would be head and shoulders better than the on-board optical?

Thanks!!!

 

With optical out, it will all depend on how decent your speakers are.

 

Rather go for a decent Coax S/PDIF since that makes life easier and the cables less expensive than TOSLINK.

 

With optical out, you basically remove the limitations of your onboard DAC. [Which is going to be cheap and budget]

So that means your weakest link is no longer the analogue line and the lousy quality conversion which your computer did.

You will now have other factors to consider.

1) The quality of your source. For example, mp3s do not sound as good as actual high quality recordings done in lossless. The difference becomes obvious when you compare audiophile level recordings in mp3 and in full quality.

2) The quality of your DAC [Digital Analogue Convertor] Once you are freed from your computer doing the sound conversion, you will need something to do its job. So if you hook it up to some lousy DAC, then you will find that you are no better off hooking it straight to your computer's output. There are people who are very hardcore and spend thousands of dollars just on their DAC. Your options will vary from pure DAC units to the typical huge hi-fi amplifiers who can accept digital inputs. [They should have a DAC built in them.]

3) And finally, as HAL 9k has said, all the best quality sound plugged into bad speakers would just downgrade everything back to abysmal levels.

So you actually have 3 things to consider.

Don't kill yourself with any one portion only to neglect the other 2. It's always the weakest link which will downgrade your audio experience.

As a more direct answer to your question though, I believe you will hear a difference if you play a high quality recording and use a good earphone/speaker unit without bothering with optical out.

If you go down the optical path, the 3 areas above do require you to spend quite a bit but the difference is astonishing. I originally gave a budget price here but that's just silly. Everyone has a different level of "satisfaction" and realistic budget. Just as long as you keep in mind that your final sound quality is usually determined by the weakest link between your audio source, DAC, and speakers, you'd be able to find something which best suits your own needs.

Hope that helps!

 

That's a very open ended question to answer since there are so many possibilities we haven't covered yet.

What kind of source are you using? [mp3? CD? Audiophile CD?]
How do you intend to listen to it? [Earphones? Desktop Speakers? Hi Fi System? Audiophile level speakers?]

Having said that...I will hazard a guess that the difference wouldn't be head and shoulders better.

If you would like to hear a head and shoulders difference, you'd have to go the high quality recording=>optical out=> high quality DAC=> high quality speakers route. That's often a whole new can of worms.

 

... and replace them with the DAC in the preamp, which, if it's a consumer-grade integrated amp likely isn't going to be much better.

For some computers (read: Those with certain Creative cards), you even lose fidelity because the card resamples everything to a fixed rate before sending it out the S/P-DIF port. Most Vaios should be fine, though, but for CDs, WAVs, FLACs and other lossless digital formats, you also want to use a player that can bypass the mixer and send the data verbatim.

(The same holds true for using HDMI for sound, by the way)

 

This requires a little bit of technical background to make the answer easy to understand but I'll try to keep it simple.

It helps to understand the concept of analogues so first things first: what is sound? Answer: its a compression wave in air and the compression/rarefaction makes your ear drum resonate in sympathy. I won't go into the inner workings of the ear but you perceive this stimulus as sound and it is one of the reasons why you can't hear sound in a vacuum (no gas/liquid/solid that can be used as a transmission medium).

Now we can make an electrical analogue of this using a microphone. About the simplest I can boil this down to is a dynamic mic which is a little membrane attached to a moving coil over a permanent magnet. So you speak into the membrane, it vibrates in sympathy with the compression/rarefaction of the air you puff out of your lungs which causes the coil to move. As the coil moves it induces a current via the principle of electromagnetic induction that varies in exactly the same manner as the air vibrating the membrane. We therefore say that the variation in air pressure and the variation in current are analogous, or that one is an analogue of the other.

In the old days we used to bung this straight onto magnetic tape and call it recording but analogue recordings are very susceptible to noise, interference, magnetic tape degrades over time and generally its all a bit of a horrible pain.

So enter digital audio. Around about this point we build up to what this is all about which is turning an analog sound source (infinitely continuous in time and space) into a digital sound source (discrete in time and space).

The principle works just like a flickbook. You make a snapshot of a moving object and if you snap enough discrete pictures per second and flick through them it looks like its moving again. So the first thing to understand is that when you buy a soundcard, this device is in its simplest form nothing more than an analogue to digital converter (ADC), a digital to analogue converter (DAC) and a pipe that streams the incoming and outgoing data to and from random memory where it can then be written to a hard drive if you want to keep it. Once its in RAM you can do whatever you want with it. Send it back out to your speakers for playback or you can manipulate/rearrange the digital audio using computer software like Audacity.

So if you can visualise the whole chain of speaking into a mic, recording it and then listening to it on your speakers it goes like this:

1) You set up a compression wave by speaking.
2) You speak close to a microphone which converts the compression wave to a tiny analogue AC signal.
3) This tiny analogue AC signal is sent down a wire to a soundcard input where an AD converter samples its amplitude lots and lots of times per second (dependent on the samplerate of the converter. i.e. a 44.1khz ADC samples 44,100 times per second).
4) The binary data is written to RAM via a process called DMA (Direct Memory Access) and may or may not be saved to a hard drive.
5) By the same process as above the binary data goes from RAM to the DAC.
6) The DAC generates a sequence of electrical pulses corresponding to the binary data which are filtered and interpolated and via this process reconstructs a tiny electrical signal from the data.
7) This tiny electrical signal goes from your soundcard output, along a wire to an amplifier where the amplifier uses a mains outlet to make the tiny electrical signal into a BIG electrical signal.
8) This big electrical signal then goes out of the amplifier and into a speaker transducer which works exactly like the microphone but in reverse. i.e. its a big magnet with a moving coil around it attached to a membrane (cone).
9) This big electrical signal makes the coil move in and out of the field of the magnet which causes the cone to vibrate and set up a compression wave which you can perceive as sound.

Phew! With that explanation out of the way...

Question: What is the advantage of using an optical out?

Answer: First, you skip a conversion stage and second, you can transfer a perfect copy of the digital audio to any other device without conversion and without interference along the way. Its the same bits and samples no matter what.

For instance, lets say you want to use your hifi because it has a nice graphic equalizer and its hooked up to really nice speakers. Use an optical out on your soundcard and plug the optical cable into the auxiliary input on your hifi. You can run the cable all the way around your house and have radio/EM interference everywhere and it won't matter because digital signals are hugely tolerant of interference so you won't pick up hum or hiss or static or any of the kind of interference noise that can manifest in analog signal lines.

Question: What makes an expensive soundcard better than a cheap one if digital audio transfer is by nature exact and highly resistent to interference?

Answer: Theres alot of snake oil around but expensive soundcards are usually expensive because:

1) Research and Development and cost of production. Lavry converter technology may be reverse engineered and then used in cheapy soundcards but Lavry still needs to recoup his expenses. So part of it is brand name, exclusivity, supporting the pioneers of our industry and consumers wanting to be on the cutting edge (although this may be misleading because the science of audio reproduction does not move rapidly like advancements in computer chip design for instance).

2) Connectivity. Most people who don't record music will only ever need a headphone output (or two), an optical out and up to 6 analogue line outs (2 needed for stereo, 6 for 5.1 surround but optical can carry this too). On the input side most people will need maybe 1 mic level input.

If you do home recording you might need MIDI, loads more inputs, some kind of sync generator (i.e. word clock), lots of preamplifiers, metering and lots of outputs for routing tricks. For everyone else its just alot of features you pay for but won't ever use. You will pay alot of money for nice preamps built into your soundcard but unless this is something you need, its alot of money you can spend better elsewhere.

Converter quality is something of a myth in my opinion although on the high priced end, more expense is lavished into optimal circuit design and error reduction but these days the difference in sound quality between soundcards that cost £100 versus £1000 is not big. I don't notice the difference side by side between any of my soundcards that I can't write off as being my imagination playing tricks on me. My ears adjust very quickly anyway so it never concerns me and I never worry about it. Yes I still use my Realtek AC97 alot when I'm not making music and I want to move out of range of my TC Konnekt (which is rackmounted and can't be moved).

Its also worth putting things into perspective in the sense that even the worst integrated soundboard converters these days are vastly superior to anything that even the super pros were using 20 years ago.

 

Hi Hayte, great detailed post.

Just checking on this part...

I used to think that way too, telling myself that if I spend just enough to ensure I have a digital stream all the way until my DAC, I'd hit audio nirvana without blowing the bank.

And then some audiophile dude started asking me, "Are your clocks synced?"

*laugh*

We can't have exact audio replication if the timing of the first device and the second device isn't in sync right?

And those silly balanced/synced stuff starts to really toast me both in terms of understanding and cost.

So I sorta avoid using "perfect" copy but I stuck with "darned good I can't really tell the difference" copy nowadays.

 

I want to say a big thanks to everyone. Before I asked the question, I did quite a bit of searching. You guys have given me more than all my previous searches combined.

In terms of your questions...

Most music is lossless WMA/MP3 I made from CD.

Speakers now are Bose Accoustimass (got tired of the 901's taking up space)

Amp/receiver is currently the weak link - 1990s midrange Sony. This is my next project.

Again, thanks!

BIJ

 

Heyas Baron,

Since you have decided to take the RED pill... *rubs hands evilly*

A few questions:
1) Are the CDs audiophile level? They may not actually sound better if they were mastered to sound good on lower quality speakers. In fact, when I use a high fidelity system, my usual music which were acceptable to me started to sound worse.
2) Did you rip the CDs accurately?

I'm just homing in on the source level first. Cos if your source ain't good, nothing else down the stream matters.

You'd have a lot of fun with deciding your DAC and Amp down the road.

Welcome to the dark side...