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Computer audio - what am I missing??

Barry, I never am. ;-)

But only because I endeavour to check before with multiple sources before I make any statement. If in doubt, rule it out.

I find a Mac and a Dac to be a perfectly laudable source, USB Async though, of course.
 
Again an informative thread. Thanks!

I'm considering going down the Mac + Rega/Young/Naim Dac (which Dac?) route.
Best wishes,
Peter
 
Rosewind said:
Again an informative thread. Thanks!

I'm considering going down the Mac + Rega/Young/Naim Dac (which Dac?) route.
Best wishes,
Peter
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Peter, something to bear in mind is that modern DACs are really very good and unless they are unusually badly designed will all sound quite similar. Of course there are differences but if on a totally arbitrary scale the sound difference between a £100 DAC and a £2000 DAC is 10% of the system sound then the difference between two pairs of £2000 speakers (let alone between one of those pairs and a pair of £4000 speakers) is more like 80%.

What I'm trying to say is that in the computer audio world you are often going to be better off spending more on your speakers relative to your front end than you would in the old days of vinyl or CD. So don't spend too long sweating about the DAC and ignoring the fact that your speakers are in fact the weakest link!

(not meaning to be rude here since I don't know what speakers you have).

Andrew
 
sonddek said:
P.S. don't use USB, and don't bother with all those Terminal tweaks and hi-fi hocus pocus: your hard drive does not suffer from acoustic feedback, and 44.1/16 data output will not tax any recent Mac.
Click to expand...

Good point on the terminal, just found out you can do it through sys.prefs!

Don't entirely agree on the don't use USB part though. Could you explain further? My DAC manufacturer recommends using their USB option (24/384) over any other connection. (AES/BNC/SPDIF).

With reference to acoustic feedback are you on about when the drive is being indexed some people might think this happens? The reason behind this is to keep the CPU as free as possible, and thats from the guys that write the software to piggy back iTunes.

Any further advice/tips on what i have done already are always welcome. Any improvement you can make to what you already have is always good!
 
Andrew B. said:
Peter, something to bear in mind is that modern DACs are really very good and unless they are unusually badly designed will all sound quite similar. Of course there are differences but if on a totally arbitrary scale the sound difference between a £100 DAC and a £2000 DAC is 10% of the system sound then the difference between two pairs of £2000 speakers (let alone between one of those pairs and a pair of £4000 speakers) is more like 80%.

What I'm trying to say is that in the computer audio world you are often going to be better off spending more on your speakers relative to your front end than you would in the old days of vinyl or CD. So don't spend too long sweating about the DAC and ignoring the fact that your speakers are in fact the weakest link!

(not meaning to be rude here since I don't know what speakers you have).

Andrew
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Completely agree, loudspeakers and room, make by far the biggest contribution, the differences say between the Audiolab and M2Tech Young are very small.
USB if properly implemented is as valid a method of transferring timed data as any other, indeed Async USB ,Async FireWire and Ethernet are technically the three best methods to transfer data.
Keith.
 
barrymidd said:
Can I be so bold as to try and explain what jitter is, seeing as virtually no-one on here seems to understand it?
Digital signals are just voltages. They are actually stepped, not continuous as in an analogue signal. When the data demands a voltage that falls between two voltages next to each other, the actual voltage oscillates between the two. THIS IS JITTER.
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A (binary) digital signal is actually an analogue signal, but it only represents two levels. So it has a huge signal to noise immunity because you only have to know whether it's above or below the mid-level to accurately reproduce it.

Digital audio is a special kind of digital signal - PCM. It's derived from an analogue waveform and ultimately ends up back that way so that you can hear it. With a PCM signal, there are two important parameters you need to know: the voltage level at each sample point, and the frequency of those sample points. Inaccuracies in either distort the re-constructed analogue audio waveform.

The voltage at each sample point is represented by the 1s and 0s, and that's pretty difficult to mess-up, but the timing of the samples is implied by knowledge of the format of the PCM signal, and can easily be distorted. Jitter is the deviation of these sampling points from the ideal and it's only relevant at the actual point that the PCM signal is converted to and from the analogue 'original' - ie at the ADC and the DAC.

HTH.
 
Just cracked it!!!

Swapped the G5 iMac I was using and not getting anything like decent sound out of it for my old mac mini G4 and it sounds bloody brilliant!

I originally bought the iMac because the mac mini only has usb1 wich is just so slow when transferring files. They are both using different versions of iTunes and osx - so the problem could be there somewhere. So thanks everyone for your input.
 
Great news that you have now got it sounding good

What this shows is that computer Audio is really not as straightforward as plugging in a DAC on a USB port - the computer and how it is set up is as important as any other audio component

Your specific situation, on a platform as popular as the G5, makes me wonder about how many people have dismissed the potential of computer audio for similar reasons...?
 
Interesting thread and outcome. I would just like to add something to the mix here, I have my imac connected to the Arcam rDAC via a Sonos ZP80, I control the Sonos via the free iphone app. This eliminates itunes and the need to change / check any settings the Sonos just picks up the lossless file and sends it to the dac in the native 16/44.1 format.

For anyone starting out you can use the Sonos without an external dac if you wish but it's onboard dac isn't great.

Obviously the other huge advantage is the mac doesn't need to be near the hifi, my Sonos connects to the router via ethernet over a powerline adaptor.
 
not sure if this is the right thread - my apologize if i'm doing something wrong.

i'm a relative newbie to the mac world. what is the best known software for CD ripping? shall i take a EAC version for mac or there's something more suitable and closer to mac world?

many thanks in advance
 
frankly speaking "listening" test is not always enough. you know that very often tracks with higher jitter sounds subjectively "better" or more "pleasant" than low jitter ones. that's why we should have also a bit more technical support on accuracy of ripping. i generally don't trust itunes much but i'm open to be proven wrong.
 
The sound of pennies dropping . . . everywhere experimenters are discovering that one bit-perfect computer can sound very different to another bit-perfect computer. Fortunately that dinosaur of an IT adage - 'bits are bit' - is en-route to extinction!

It's not voodoo: it's about bitstream timing errors and resultant jitter, and the problems created by cheap, noisy - highly compacted - components on the PC motherboard and its cheap noisy power supply.

Here's a handy guide to what jitter is, and sounds like:
http://www.antelopeaudio.com/en/digital_clocking.html

Macs call for a two-pronged approach: do everything possible to suppress hardware gremlins (remove or turn off bluetooth/wireless, swap HD for SSD, change the power supply, isolate / clean the 5V USB rail, etc). Then, as doug2507 sagely points out, look hard at the software: shutting down redundant processes and streaming file to RAM using Pure Music, Decibel or Audirvana all bring rewards.

As Keith is always keen to point out, async USB and Firewire are easier for computers to handle than SPDIF or balanced digital. But a USB cable is inevitably the data cable filling in a power cable sandwich, so you have to deal somewhere with the electrical problems created by powering chipsets in the DAC with your noisy computer.

On the other hand, giving a DAC SPDIF or AES/EBU involves taking charge of the clocking, which is a tough process to get right. Almost invariably, when a DAC has a balanced input, it sounds better this way - so tackling USB > AES/EBU conversion is often well worth the trouble. Wyred 4 Sound, for instance, recommends USB above the DAC2's SPDIF, optical or balanced digital inputs, and yet without a specialised audio computer, I think it's conspicuously better via AES/EBU. YMMV.

D-A stages have come a long way since the heyday of the high-end CD player, but as SPDIF transports, a computer is ironically far less sophisticated, for all its processing power (none of it 'designed for audio'). Directly comparing digital output from a good CD player with a computer is often enlightening - and dispiriting for fans of computer audio. Then again, we can do 24/192 . . . try that on your Naim CD5.
 
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