[tfarney]

Quote:

Originally Posted by bigshot /img/forum/go_quote.gif The easiest way would be to get a USB dongle that gives you line out. I think Griffin makes one called the iMic. It would completely solve your problem for $30 and it sounds great. See ya Steve

I actually have one of those that I bought to get a mic into the Mac. Hadn't even thought of it! So, you think that once I get around the Mac's op amp using the iMic, that an external DAC really wouldn't make much difference until I got pretty high end? I've been having second thoughts about the Duet lately, because I'm pretty happy with my amp setup and I really don't need all the ins and outs. I was surfing around earlier today, looking for simple, low-cost alternatives, and ran into this...

...man, it sure reads great. Incredible components/specs for the dollar:

* D/A Receiver chip CS-8416,
* D/A converter chip, CS-4398 (24-192KHZ )
* Dual LT1364C OPAMPS for analog output circuit
* Optical digital input
* Coaxial Digital Input
* USB input (CM-108 USB receiving chip)
* Standard RCA analog output plugs

But if I thought the difference between this, or even the Duet, and a line out of my Mac was going to be really subtle, I'd much rather spend the money on some alternative cans, or some nearfield monitors, or even a dedicated headphone amp.

Tim

 

[Solan]

Quote:

Originally Posted by Chri5peed /img/forum/go_quote.gif From the numerous, 'Optical is bad' threads, I get the idea it is a physical thing; like a pop or click. Also how it almost kills Optical and make it un-usable.

By "optical", do you refer to optical source (CD/DVD/SACD) or to optical cable? I can't recall having heard anything bad about optical cables, but would be very interested to hear if they were flawed, as I am considering buying an Apogee mini-DAC without USB or FireWire.

 

[tfarney]

Quote:

Originally Posted by Solan /img/forum/go_quote.gif By "optical", do you refer to optical source (CD/DVD/SACD) or to optical cable? I can't recall having heard anything bad about optical cables, but would be very interested to hear if they were flawed, as I am considering buying an Apogee mini-DAC without USB or FireWire.

Optical cable. It is reported in some circles (often circles including those selling solutions - caveat emptor) to be the single biggest source of jitter. And I don't doubt it, but if, as others report, jitter levels are below audibility in almost all decent consumer digital systems, it doesn't matter much.

Tim

 

[Solan]

If it's optical cable, that's one argument pro getting the USB or FW version, then, even though the argument may be tenuous and more convincing to the seller than to the buyer.

At the other end of the scale: What does your purple budget DAC above sell for?

 

[nick_charles]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Optical cable. It is reported in some circles (often circles including those selling solutions - caveat emptor) to be the single biggest source of jitter. And I don't doubt it, but if, as others report, jitter levels are below audibility in almost all decent consumer digital systems, it doesn't matter much. Tim

My DAC has optical and coax in and my Marantz has optical and coax in, so I did some quick testing of the two, personally I could not discern any difference whatsoever, in the end I dropped coax and went all optical. But I have not tested this rigorously, perhaps I will do that now and see what difference there is...

Okay, this is what I did. I sent the coax and optical to my DAC from my Marantz. Then I recorded the same track 4 times twice with coax and twice with optical via my Edirol soundcard as 16/44.1 wav files. The I ran FooBar's ABX on these files, no difference, I got exactly 50% , i.e pure guesswork.

Then I editted the files to trim them to the same start point, within 0.000001 of a second. The I ran a spectrum analyser on them. The differences between them are well within the random vraiation of my card, the average level difference across the entire audible spectrum was 0.007208796 db, the worst deviation was at 21963hz where the optical was 0.420143, up to 20068hz the average difference was -0.00015179 db.

To me this is as close to identical as makes no practical difference. For reference my DAC is an Entech 203.2

 

[tfarney]

Quote:

Originally Posted by Solan /img/forum/go_quote.gif If it's optical cable, that's one argument pro getting the USB or FW version, then, even though the argument may be tenuous and more convincing to the seller than to the buyer. At the other end of the scale: What does your purple budget DAC above sell for?

$110. And the purple is classy, don't you think?

Tim

 

[tfarney]

Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif My DAC has optical and coax in and my Marantz has optical and coax in, so I did some quick testing of the two, personally I could not discern any difference whatsoever, in the end I dropped coax and went all optical. But I have not tested this rigorously, perhaps I will do that now and see what difference there is... Okay, this is what I did. I sent the coax and optical to my DAC from my Marantz. Then I recorded the same track 4 times twice with coax and twice with optical via my Edirol soundcard as 16/44.1 wav files. The I ran FooBar's ABX on these files, no difference, I got exactly 50% , i.e pure guesswork. Then I editted the files to trim them to the same start point, within 0.000001 of a second. The I ran a spectrum analyser on them. The differences between them are well within the random vraiation of my card, the average level difference across the entire audible spectrum was 0.007208796 db, the worst deviation was at 21963hz where the optical was 0.420143, up to 20068hz the average difference was -0.00015179 db. To me this is as close to identical as makes no practical difference. For reference my DAC is an Entech 203.2

And yet, as I said in another thread last week, I recently ran into a product designed to remove the jitter from your $79 Apple Airport Express, selling for over $1300.

Yea, though I walk through the valley of the shadow of upgrades, I shall keep my hand upon my wallet.

Tim

 

[HeadphoneAddict]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif I actually have one of those that I bought to get a mic into the Mac. Hadn't even thought of it! So, you think that once I get around the Mac's op amp using the iMic, that an external DAC really wouldn't make much difference until I got pretty high end? I've been having second thoughts about the Duet lately, because I'm pretty happy with my amp setup and I really don't need all the ins and outs. I was surfing around earlier today, looking for simple, low-cost alternatives, and ran into this... ...man, it sure reads great. Incredible components/specs for the dollar: * D/A Receiver chip CS-8416, * D/A converter chip, CS-4398 (24-192KHZ ) * Dual LT1364C OPAMPS for analog output circuit * Optical digital input * Coaxial Digital Input * USB input (CM-108 USB receiving chip) * Standard RCA analog output plugs But if I thought the difference between this, or even the Duet, and a line out of my Mac was going to be really subtle, I'd much rather spend the money on some alternative cans, or some nearfield monitors, or even a dedicated headphone amp. Tim

I have one of these that I bought from Super Pro DAC707

It sounds better than my Macbook and iBook line out, and sounds similar to the iBasso D1 line-out, but at less than half the cost (although the D1 also has a nice headphone amp and can run on battery too). It has a very similar chipset to the D1 as well as similar to the 2006 HR Micro DAC that I have, but the Super pro DAC and D1 are a little less warm and thus a little less full sounding vs the HeadRoom (which is also more expensive). So, I prefer the HR Micro DAC, but the Super Pro DAC is 95% of the HR in sound quality.

Based on the audible improvements the above DAC give to the Mac, vs the built-in opamps, you could use any of the above.

But, for a Mac Powerbook with no optical, your best best for the best/max upgraded sound out is the Apogee Duet FireWire or the Headamp Pico. I use the Pico on my iBook to feed a full size amp, and it uses a receiver chip (PCM2706) to convert the USB and feed it as I2S to the AD1796 upconverter, and sends the reclocked 24/96 signal into the WM8740 (wolfson high end DAC). I picked the Pico because it can work on Mac or PC, while the Duet is Mac only.

Having chosen the Pico for my iBook DAC, I relegated the Super pro DAC to my Apple TV, since my AV receiver has no more optical/coax inputs available after plugging in my DVD and HDTV cable box. The Micro DAC is in my bedside rig, and the D1 is my portable DAC. Finally the Apogee mini-DAC with Sigma 11 PSU is in my main rig.

Is that enough DAC's for you

 

[tfarney]

Quote:

s that enough DAC's for you

We're getting there

. One commet confused me a bit, though:

Quote:

I have one of these that I bought from Super Pro DAC707 It sounds better than my Macbook and iBook line out

And...

Quote:

Quote: Based on the audible improvements the above DAC give to the Mac, vs the built-in opamps, you could use any of the above. Does the use of my iMic USB not go around the Mac's op amps, providing me with a line out?

Are those audible improvement vs the built-in op amps or audible improvements vs. the built-in DAC that I'm likely to hear when comparing to my Mac with the line out? Or am I just confused...this is a likelihood. And last but not least, what are these audible improvements? And how do they scale up as you go up the DAC food chain? I don't really need the built-in amps of the Duet or the Pico, but if a Super DAC and/or a HR micro dac will only give me a small advangate I'll have to strain to hear and the leap to the Pico or Duet will get me much more, I'm willing to spend the extra money. As soon as i acquire some

.

Tim

 

[bigshot]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif if I thought the difference between this, or even the Duet, and a line out of my Mac was going to be really subtle, I'd much rather spend the money on some alternative cans, or some nearfield monitors, or even a dedicated headphone amp.

That's a bingo.

See ya
Steve

 

[bigshot]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Optical cable. It is reported in some circles (often circles including those selling solutions - caveat emptor) to be the single biggest source of jitter. And I don't doubt it, but if, as others report, jitter levels are below audibility in almost all decent consumer digital systems, it doesn't matter much.

I use optical from my Macbook to resolve DTS 5:1 sound. There is absolutely nothing wrong with optical. Jitter is a hoodoo.

See ya
Steve

 

[Know Talent]

Quote:

Originally Posted by bigshot /img/forum/go_quote.gif I use optical from my Macbook to resolve DTS 5:1 sound. There is absolutely nothing wrong with optical. Jitter is a hoodoo. See ya Steve

But I can hear the difference between .75 and .90 Speed of Light electron velocity in IC's!

...and the .90 is worth the extra $2000 per meter

A bat could not detect the differences some of these a**clowns claim provide "stunning" improvements

 

[nick_charles]

Quote:

Originally Posted by bigshot /img/forum/go_quote.gif I use optical from my Macbook to resolve DTS 5:1 sound. There is absolutely nothing wrong with optical. Jitter is a hoodoo. See ya Steve

I use optical exclusively and I even have a 3:1 optical switch box, I have never detected any problems with optical nor any (audible) differences between optical and coax. That said, I have consistently found minor differences in the waveforms when digitizing the analog outputs from a DAC fed with either optical or coax. We are talking differences so small that they make the legendary power cable waveform differences look like Barn doors by comparison and you are zooming down to sample level to even see them, measured in a sound program they show up as tiny differences in min , max and average sample levels but on an energy level measured in DBs there is no difference whatsoever.

Mind you I strongly suspect that if I compared multiple attempts to digitize the same signal using the same cable type I would find the exact same sample level variations. I will check the files I did over the weekend...

EDIT:

Yep the variations between two attempts to digitize the same section both from coax cable had similar variations, even with very very careful alignment and trimming the average variation was 0.26db acress the audible spectrum. Far more variable than I would like. Comfortably swamping any possible optical vs coax differeence.

 

[bigshot]

In any case, differences that small are inaudible. And if you aren't converting back and forth from analogue to digital, it won't be cumulative. I admire your tenacity to chase things down to the smallest level. I usually just test to figure out how to apply it in practice and leave it at that. I'm a lazy sort of guy when it comes to stuff like that.

See ya
Steve

 

[ricmat]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Optical cable. It is reported in some circles (often circles including those selling solutions - caveat emptor) to be the single biggest source of jitter. And I don't doubt it, but if, as others report, jitter levels are below audibility in almost all decent consumer digital systems, it doesn't matter much. Tim

why do you say so?

it is weird to hear this. maybe there's something I'm not catching, but optical is meant to be as fast as it can be and perfect delivering each bit!

that's why telecoms are moving into them!