Head-Fi.org › Forums › Equipment Forums › Computer Audio › Jitter issues with Macbook Pro optical out?
New Posts  All Forums:Forum Nav:

Jitter issues with Macbook Pro optical out?

post #1 of 13
4/24/10 at 5:15pm
Thread Starter 
An acquaintance of mine recently told me that the optical out jack on my Macbook Pro has "horrible jitter issues" after I told him that I'm considering a nice optical DAC to pair with my Macbook Pro. I was taken aback, because I've seen quite a number of people running pretty decent (less than 1K) DACs out of their Macbooks without any issues.

This is the first time I've heard about this, though I am a greenhorn in this area. He suggested that I get a USB to SPDIF converter to reduce jitter. Or a USB to BNC if something like that was out there because "BNC being 75ohm has close to 0 jitter".

I didn't get much time to ask him about his comment as we had to leave quite urgently. I tried googling and searching about this, but sometimes I can't quite understand what's being said as the articles get quite technical.

Can anyone comment on this or point me in the right direction to learn more?
Thanks a bunch guys!
Reply
post #2 of 13
4/24/10 at 5:22pm
I've heard good things about the Macbook Pro optical out. I would trust it for a lower end setup. I used to run a similar setup, laptop --> 3.5mm optical out --> Zero DAC.

If you do want to take things a little higher, you can get an M2tech Hiface with a Coaxial RCA or BNC output. (If you can find a suitable DAC with a BNC input.)
Reply
post #3 of 13
4/24/10 at 5:33pm
Sounds like your friend drank too much audiophile kool aide. Yes, optical cable has higher jitter than USB or coax, but I doubt he can hear it. I have a transporter that allows me to convert the USB output of my MacBook Pro to coax, optical or AES/EBU. That optical output, which bi-passes the optical output of my MacBook Pro completely, sounds exactly like the output of my MacBook Pro. By the way, the same transporter allows me to quickly and easily compare optical and coax. I can hear no difference there either, at least not while listening to music. I've tried those listening exercises where you repeatedly listen to certain passages, for certain artifacts, to ID the minute differences between players, file formats, cables, etc. After a few runs, I always want to listen to the music and am struck by what a remarkably futile exercise it is to "listen in" for problems that are not at all evident when listening to what the system was made for. Lack of focus, perhaps. Maybe I should try doing it with music that sucks, that I really don't want to listen to.

YMMV, of course, put I believe I'd plug into whatever is convenient and enjoy the music.

P
Reply
post #4 of 13
4/25/10 at 2:00am
Thread Starter 
Quote:
Originally Posted by Hybrys View Post
I've heard good things about the Macbook Pro optical out. I would trust it for a lower end setup. I used to run a similar setup, laptop --> 3.5mm optical out --> Zero DAC.

If you do want to take things a little higher, you can get an M2tech Hiface with a Coaxial RCA or BNC output. (If you can find a suitable DAC with a BNC input.)
Ah! I realised that there aren't that many DACs with a BNC port available. Of the DACs I've been looking at, I think the Matrix i-mini Bel Canto lookalike is the only one with a BNC port available.

Quote:
Originally Posted by Phelonious Ponk View Post
Sounds like your friend drank too much audiophile kool aide. Yes, optical cable has higher jitter than USB or coax, but I doubt he can hear it. I have a transporter that allows me to convert the USB output of my MacBook Pro to coax, optical or AES/EBU. That optical output, which bi-passes the optical output of my MacBook Pro completely, sounds exactly like the output of my MacBook Pro. By the way, the same transporter allows me to quickly and easily compare optical and coax. I can hear no difference there either, at least not while listening to music. I've tried those listening exercises where you repeatedly listen to certain passages, for certain artifacts, to ID the minute differences between players, file formats, cables, etc. After a few runs, I always want to listen to the music and am struck by what a remarkably futile exercise it is to "listen in" for problems that are not at all evident when listening to what the system was made for. Lack of focus, perhaps. Maybe I should try doing it with music that sucks, that I really don't want to listen to.

YMMV, of course, put I believe I'd plug into whatever is convenient and enjoy the music.

P
Haha, yeah the chap who told me about this tends to be a bit over the top with the audiophoolery. He does all kinds of weird things, like coating his CDs in some special goo and a whole host of other really weird sh*t.

I always thought that running audio the optical output into a DAC would yield better sound than from the USB port. If jitter is higher with optical, than I guess it isn't as superior to USB as I initially thought. Hmmm, but yeah I would have to agree with you, after a certain level the differences are really subtle.

Jitter seems to be such a thorny subject. I'll go dig into this deeper but in the meantime thanks guys!
Reply
post #5 of 13
4/25/10 at 2:48am
Quote:
Originally Posted by milesandcoltrane View Post
Ah! I realised that there aren't that many DACs with a BNC port available. Of the DACs I've been looking at, I think the Matrix i-mini Bel Canto lookalike is the only one with a BNC port available
The Little Dot DAC-I actually has a BNC input. My eventual setup goes like this:

Computer --> M2Tech Hiface (BNC) --> Little Dot DAC-I --> Little Dot MKVI+ --> Denon D2000 recabled balanced + MarkL.
Reply
post #6 of 13
4/25/10 at 4:19am
Quote:
If jitter is higher with optical, than I guess it isn't as superior to USB as I initially thought. Hmmm, but yeah I would have to agree with you, after a certain level the differences are really subtle.
"Subtle" may be overstating it. Jitter is a bit of a paper tiger, and optical may be better, as it provides complete electrical isolation from the noisy environment of the computer, which unlike jitter, can be a clearly audible problem. Even then, I think the isolation of optical is a solution to a largely theoretical problem. The real problem, the high noise floor, is addressed by simply getting all analog audio outside of the computer. All this takes is a good DAC. The interface used to connect it is pretty irrelevant if the implementation is competent, and competent is cheap and easy. The technology is mature. The great wringing of hands over jitter is mostly driven by companies selling its further reduction below what is already inaudible in 99.99% of the playback systems. Enjoy the music. You want better sound? Buy better headphones. When you've got the ultimate headphones (and speakers) of your dreams, driven by an excess of squeaky clean power, and you still have money you don't know what to do with, then it will be time to worry about things like what kind of digital interface delivers your zeros and ones. Maybe. If you have too much time on your hands.

P
Reply
post #7 of 13
4/25/10 at 8:45am
Thread Starter 
Quote:
Originally Posted by Hybrys View Post
The Little Dot DAC-I actually has a BNC input. My eventual setup goes like this:

Computer --> M2Tech Hiface (BNC) --> Little Dot DAC-I --> Little Dot MKVI+ --> Denon D2000 recabled balanced + MarkL.
Hmm that's quite nice! I'll definitely take a look at the Little Dot DAC-I.

Quote:
Originally Posted by Phelonious Ponk View Post
"Subtle" may be overstating it. Jitter is a bit of a paper tiger, and optical may be better, as it provides complete electrical isolation from the noisy environment of the computer, which unlike jitter, can be a clearly audible problem. Even then, I think the isolation of optical is a solution to a largely theoretical problem. The real problem, the high noise floor, is addressed by simply getting all analog audio outside of the computer. All this takes is a good DAC. The interface used to connect it is pretty irrelevant if the implementation is competent, and competent is cheap and easy. The technology is mature. The great wringing of hands over jitter is mostly driven by companies selling its further reduction below what is already inaudible in 99.99% of the playback systems. Enjoy the music. You want better sound? Buy better headphones. When you've got the ultimate headphones (and speakers) of your dreams, driven by an excess of squeaky clean power, and you still have money you don't know what to do with, then it will be time to worry about things like what kind of digital interface delivers your zeros and ones. Maybe. If you have too much time on your hands.

P
I like how you put it =) Sometimes we throw ourselves into a big frenzy discussing the relative merits and demerits of the slightest and smallest issues.

I still believe the headphone/speaker part of the equation makes the most difference, ranking right alongside the mastering quality of the recording in question. Then comes the source, then amplifier, then cables. I'm not too sure where to place power. This is in my limited experience though.

Alrighty then, I'll just go with a flow and get a decent DAC to start with.

Thanks again guys!
Reply
post #8 of 13
4/25/10 at 7:09pm
Quote:
Originally Posted by Phelonious Ponk View Post
I'd plug into whatever is convenient and enjoy the music.

Best advice I've read in a long time!
Reply
post #9 of 13
4/25/10 at 9:00pm
Ask your friend to back up his claims with some actual data and test results.

Macs - since 1984 - have had fine audio output.

The "problem" is that a MacBook is widely known by the public and is easily obtained. It doesn't require ye olde magickal audiophile knowledge to use one.

When status and esoteric "knowledge" are in play, the common becomes "garbage" because it's common. Whether there are any actual faults doesn't matter so much. Anything well-known and easily found is assumed to be crap because, otherwise, it threatens said mystical knowledge.
Reply
post #10 of 13
4/25/10 at 9:05pm
Ask your friend to back up his claims with some actual data and test results.

Macs - since 1984 - have had fine audio output.

The "problem" is that a MacBook is widely known by the public and is easily obtained. It doesn't require ye olde magickal audiophile knowledge to use one.

When status and esoteric "knowledge" are in play, the common becomes "garbage" because it's common. Whether there are any actual faults doesn't matter so much. Anything well-known and easily is assumed to be crap because, otherwise, it threatens said mystical knowledge.
Reply
post #11 of 13
4/25/10 at 11:50pm
Please skip the koolaid and move on to a bourbon on ice....
***meaning pour yourself a drink, relax and enjoy the music, if your hear something funny, stop drinking and go to bed...
Cheers!!!
Reply
post #12 of 13
4/26/10 at 12:44am
Some people have had good results using the Hiface and other USB to coax devices instead of direct USB or optical with their DACs. It probably depends more on the DAC itself than anything as to how much improvement they will make.
Reply
post #13 of 13
3/14/11 at 12:46am

I think i know where the problem is:

listening to 44.1/16 or 48/16 songs is no problem.

I cannot hear a difference between the digital line out and the usb out put.

However, the jitter becomes a major problem when you try something of a higher sampling and bitrate.

When i listen to tracks that are 96/24, jitter becomes a major problem, and it is just frustrating listening to those tracks with the toslink out put.

Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Computer Audio
Head-Fi.org › Forums › Equipment Forums › Computer Audio › Jitter issues with Macbook Pro optical out?