Audio lover with keen ears – cannot tell difference between laptop and dedicated DAC/Amp. Why not?
Oct 11, 2016 at 8:15 PM Thread Starter Post #1 of 10

svk7

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Hi there. Audio lover here. I consider myself to have pretty keen ears. I can usually do very well on 128 kbps vs 320 kbps tests, and have written extensively on the crappy quality of the iPhone 6s' audio jack vs the iPhone 5's, which fairs pretty well (http://www.head-fi.org/t/820722/why-even-though-i-am-sticking-with-my-iphone-6s-for-now-i-am-not-lamenting-the-loss-of-the-headphone-jack-on-the-iphone-7-an-audio-lover-s-perspective).
 
So I don't think I'm a total newbie when it comes to these things. However, I cannot, for the life of me, tell any difference between the sound coming out of my laptop vs that coming out of my DAC/Amp.
 
MacBook Pro's Cirrus Logic CS4206A (AB 11) vs Oppo HA-2's ESS Sabre32 Reference ES9018-K2M
 
My setup is typically as follows:
MBP –> 256-320 kbps iTunes files / Tidal (Hi-Fi) –> (USB to Oppo HA-2) –> V-Moda M-100's, JH Audio 13v2's, or JH Audio Roxanne's.
 
I can definitely hear a difference between my iPhone 6s to iPhone 6s –> Oppo HA-2, but that's not impressive because I can easily tell the difference between the iPhone 5 and 6s. I just think the 6s has an extremely crappy DAC/Amp combo. My worry is that the iPhone 5 and MBP sound just about as good as the MBP –> Oppo HA-2.
 
Am I missing something? Should I be listening for something in particular (besides the usual "how do the cymbals sound), etc.?
 
Thanks for any insight.
 
Oct 11, 2016 at 10:39 PM Post #2 of 10

theveterans

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The differences between DACs are very subtle.
 
IMO, a very different sounding DAC will have the almost the same tonality as other DACs since amps and transducers pretty much define tonality, but there's a layer of "depth" and "realism" across all frequencies that varies on DACs. Even that depth is just very subtle and as such, not obvious if you haven't listened to your DAC for long hours.
 
Oct 11, 2016 at 10:52 PM Post #3 of 10

svk7

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Thank you for your thoughtful response. Maybe I'm having an especially hard time hearing any differences because I haven't really been able to get a good grip of the sound of the 13v2's and Roxanne's and as I have been constantly switching back and forth between the two?
 
I'd say I have >600 hours on the MacBook Pro, >400 hours on the Oppo HA-2, and 40 hours on the 13v2's and Roxanne's. But neither of the latter on just one of the sources but a combination of iPhone 5, iPhone 6s –> Oppo HA-2, MBP, and MBP –> Oppo HA-2.
 
Should one of the two DAC (CS4206A vs Sabre ES9018-K2M) / Amp combos blow the other one out of the water on paper? And would maybe differences between the two be more evident using full sized cans or something that requires much higher output impedances? The isolation is so good on the JH Audios that I seldom turn up the volume more than halfway – whether that's iPhone or MBP – bc I don't want hearing damage. But maybe the differences shine when you require more power (i.e., more volume) out of the source? So how each source handles ear-bleeding volumes on IEMs or very high volumes on demanding headphones if that makes sense?
 
Oct 11, 2016 at 11:38 PM Post #4 of 10

theveterans

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There's always impedance matching with amps. To truly test a DAC, both amp and IEMs should be the same and only the DAC varies. I think that if you don't hear a difference in the sound between the CS4206A on your MBP and the ES9018 on a specific IEM, that just means that both amps are properly powering your IEM and that those two DACs aren't that different at all. IMO, I would suggest for you to audition a custom DAC chip like on the Chord Mojo and see if you can finally hear the difference. I believe that the Mojo's amp is more than enough to power your IEMs, thus eliminating the amp bias.
 
The issue with the sound from smartphone's headphone output against an external DAC/amp is due to power delivery and impedance matching of your IEMs. The smartphone usually has a much lower power output and a slightly higher output impedance leading to a different sound from an external DAC/amp  with much more powerful headphone out. In the case of the MBP, there is more power output to the headphone jack more than your IEM needs; likewise with your Oppo HA-2. In that case, you're truly (99.5%) comparing DACs only while on the smartphone you're comparing both DAC and AMP with the AMP giving much more of the difference than the DACs.
 
As a final note before giving up on DAC differences, I would try the Chord Mojo as that DAC uses Chord's in-house FPGA DAC rather than using a DAC chip from another chip maker such as Cirrus Logic or ESS Sabre.
 
Oct 11, 2016 at 11:42 PM Post #5 of 10

theveterans

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You don't need ear-splitting volumes to test the difference. Volume matching at your typical listening levels is enough. The difference presents itself as being more "real-life sounding" e.g. the DAC makes you think that you're listing at the front row of a jazz band with the instruments sounding true to life rather than synthetic. However, I emphasize that those differences are subtle, and for that reason some say that all DACs sound the same or you're just hearing a placebo effect.
 
Oct 11, 2016 at 11:46 PM Post #6 of 10
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What music are you listening to? A lot of music is either compressed or less than ideally mastered.
 
Oct 11, 2016 at 11:55 PM Post #7 of 10

Kerry56

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Tom's Hardware did an interesting double blind DAC test a couple of years ago.  Their conclusion was that they couldn't reliably tell a $2 Realtek DAC in a motherboard from a $2000 external DAC.  http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html
 
I personally can't tell the difference between the DAC in my Fiio E10 from the DAC in my motherboard.  The amp in the Fiio does make a difference with certain headphones.
 
Oct 12, 2016 at 7:22 AM Post #8 of 10

ProtegeManiac

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Quote:
Originally Posted by svk7 /img/forum/go_quote.gif
Hi there. Audio lover here. I consider myself to have pretty keen ears. I can usually do very well on 128 kbps vs 320 kbps tests, and have written extensively on the crappy quality of the iPhone 6s' audio jack vs the iPhone 5's, which fairs pretty well (http://www.head-fi.org/t/820722/why-even-though-i-am-sticking-with-my-iphone-6s-for-now-i-am-not-lamenting-the-loss-of-the-headphone-jack-on-the-iphone-7-an-audio-lover-s-perspective).
 
So I don't think I'm a total newbie when it comes to these things. However, I cannot, for the life of me, tell any difference between the sound coming out of my laptop vs that coming out of my DAC/Amp.
 
MacBook Pro's Cirrus Logic CS4206A (AB 11) vs Oppo HA-2's ESS Sabre32 Reference ES9018-K2M
 
My setup is typically as follows:
MBP –> 256-320 kbps iTunes files / Tidal (Hi-Fi) –> (USB to Oppo HA-2) –> V-Moda M-100's, JH Audio 13v2's, or JH Audio Roxanne's.
 
I can definitely hear a difference between my iPhone 6s to iPhone 6s –> Oppo HA-2, but that's not impressive because I can easily tell the difference between the iPhone 5 and 6s. I just think the 6s has an extremely crappy DAC/Amp combo. My worry is that the iPhone 5 and MBP sound just about as good as the MBP –> Oppo HA-2.
 
Am I missing something? Should I be listening for something in particular (besides the usual "how do the cymbals sound), etc.?
 
Thanks for any insight.

 
DACs have a lot lower effect on the signal, and when they do have an easily audible difference in performance, it usually has a lot more to do with how the analogue signal coming from the DAC chip is handled by the rest of the circuit. The amplifier is a lot more of a factor. Distortion increases as you make the amp put out more power to drive whatever is hooked up to it. Amps and mainstream devices basically vary on how much power they can spit out before hitting audible distortion levels or how sharply distortion piles on, so one amp can spit out 1watt at 1% distortion, another amp can spit out 250mW at 1% distortion, and then something like a tablet or laptop can spit out maybe 25mW at 1% distortion, all at 32ohms. All of these would spit out a lot less at 300ohms (the only exception would be OTL tube amps which have their max output at 300ohms).
 
Now, as output power on the amp rises, it isn't just distortion (and noise) that rises with it, but also the output in decibels from whatever is hooked up to it. Two things come in as to whether you'll get to audible distortion or not. First, you might not be listening that loud anyway for even a mainstream device to run out of steam. Second, headphones also vary in sensitivity and efficiency, in other words some can get much louder than others given the same amount of power input. In your case you have IEMs which are very high efficiency transducers for their intended use, and also the M100, which is of a fairly high efficiency for a fullsize headphone. It can also be a combination of both factors. Whichever it is, you can get well past safe listening levels on your headphones and IEMs before you get the Macbook to easily audible distortion levels.
 
If for example you were using a low efficiency or high impedance headphone, like the HE400i and the HD600, then those are more likely to get the Macbook to run out of steam.
 
Oct 12, 2016 at 12:24 PM Post #9 of 10

svk7

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  There's always impedance matching with amps. To truly test a DAC, both amp and IEMs should be the same and only the DAC varies. I think that if you don't hear a difference in the sound between the CS4206A on your MBP and the ES9018 on a specific IEM, that just means that both amps are properly powering your IEM and that those two DACs aren't that different at all. IMO, I would suggest for you to audition a custom DAC chip like on the Chord Mojo and see if you can finally hear the difference. I believe that the Mojo's amp is more than enough to power your IEMs, thus eliminating the amp bias.
 
The issue with the sound from smartphone's headphone output against an external DAC/amp is due to power delivery and impedance matching of your IEMs. The smartphone usually has a much lower power output and a slightly higher output impedance leading to a different sound from an external DAC/amp  with much more powerful headphone out. In the case of the MBP, there is more power output to the headphone jack more than your IEM needs; likewise with your Oppo HA-2. In that case, you're truly (99.5%) comparing DACs only while on the smartphone you're comparing both DAC and AMP with the AMP giving much more of the difference than the DACs.
 
As a final note before giving up on DAC differences, I would try the Chord Mojo as that DAC uses Chord's in-house FPGA DAC rather than using a DAC chip from another chip maker such as Cirrus Logic or ESS Sabre.

 
I guess I could do that by running a line out from my MBP to the line in on the Oppo HA-2 and see if I can tell the difference. Although I'm fairly certain that most gains are first found in the Amp than in the DAC. So I guess the MBP and HA-2 amp are comparable.
 
Will do, just bought a Chord Mojo new for $406.
 
  You don't need ear-splitting volumes to test the difference. Volume matching at your typical listening levels is enough. The difference presents itself as being more "real-life sounding" e.g. the DAC makes you think that you're listing at the front row of a jazz band with the instruments sounding true to life rather than synthetic. However, I emphasize that those differences are subtle, and for that reason some say that all DACs sound the same or you're just hearing a placebo effect.

 
Hmm interesting. Maybe what I was going for more is that you can tell differences between the quality of amps at higher volumes (and therefore it's better to do it with extremely power hungry headphones, as you need more of the amp's oomph to get you to a not-ear-bleeding volume, you need not destroy your ears in the process; also, it might attest more to the quality of the headphones than anything else to see if your music distorts at high volumes). What you say about DACs make sense though. The volume you listen to your music has really nothing to do with the DAC but is all in the Amp component. Maybe all along I was really trying to compare the two Amps.
 
  What music are you listening to? A lot of music is either compressed or less than ideally mastered.

 
Mostly either 256 AAC Mastered for iTunes, 320 mp3, or TIDAL Hi-Fi (I couldn't really tell the difference between either of the three). I listen to all genre: Rock, Pop, EDM, Classical, Country, etc.
 
  Tom's Hardware did an interesting double blind DAC test a couple of years ago.  Their conclusion was that they couldn't reliably tell a $2 Realtek DAC in a motherboard from a $2000 external DAC.  http://www.tomshardware.com/reviews/high-end-pc-audio,3733.html
 
I personally can't tell the difference between the DAC in my Fiio E10 from the DAC in my motherboard.  The amp in the Fiio does make a difference with certain headphones.

 
Thans for the link! Very interesting read. Confirms it's really the quality of the Amp that I'm after.
 
 
DACs have a lot lower effect on the signal, and when they do have an easily audible difference in performance, it usually has a lot more to do with how the analogue signal coming from the DAC chip is handled by the rest of the circuit. The amplifier is a lot more of a factor. Distortion increases as you make the amp put out more power to drive whatever is hooked up to it. Amps and mainstream devices basically vary on how much power they can spit out before hitting audible distortion levels or how sharply distortion piles on, so one amp can spit out 1watt at 1% distortion, another amp can spit out 250mW at 1% distortion, and then something like a tablet or laptop can spit out maybe 25mW at 1% distortion, all at 32ohms. All of these would spit out a lot less at 300ohms (the only exception would be OTL tube amps which have their max output at 300ohms).
 
Now, as output power on the amp rises, it isn't just distortion (and noise) that rises with it, but also the output in decibels from whatever is hooked up to it. Two things come in as to whether you'll get to audible distortion or not. First, you might not be listening that loud anyway for even a mainstream device to run out of steam. Second, headphones also vary in sensitivity and efficiency, in other words some can get much louder than others given the same amount of power input. In your case you have IEMs which are very high efficiency transducers for their intended use, and also the M100, which is of a fairly high efficiency for a fullsize headphone. It can also be a combination of both factors. Whichever it is, you can get well past safe listening levels on your headphones and IEMs before you get the Macbook to easily audible distortion levels.
 
If for example you were using a low efficiency or high impedance headphone, like the HE400i and the HD600, then those are more likely to get the Macbook to run out of steam.

 
Extremely well explained. Thank you, kind sir. I hope everyone who reads this will give you some reputation points for it because you deserve every last one of them.
 
Oct 12, 2016 at 12:27 PM Post #10 of 10

svk7

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I think what I've decided to do is to sell the Oppo HA-2 and go for the Chord Mojo, which I hope will give me a completely transparent, black background for my IEMs as I detect a very, very slight hiss with my JH Audios when no music is playing (although not nearly as much as I had with my SE846's before I sold those). Got the Mojo from Amazon UK brand new for $405. I think it's a bug. Will make a post about it soon.
 

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