External DAC's for iDevices.
Jun 5, 2013 at 2:00 PM Post #16 of 44
Quote:
I'm just a vulnerable to the entire expectation/cost variable, as the next guy.  But my ears tell me its better.  The richness of the listening experience has gone up.  And I invite anyone to listen, and judge for themselves.

 
How long a time was there between the sample with the external DAC and without? You would need two iPods to be able to do direct A/B switching. Otherwise there would be problems with auditory memory. And if you didn't level match, that is going to throw things off too. Everyone around here seems stuck on sighted vs double blind tests, but direct switching and level matching is MUCH more important than going blind.
 
I spent several days setting up a shootout between an iPod loaded with an AIFF file through line out and the original CD in a very good midrange CD player. I carefully balanced the line levels, because they weren't the same, and set up an A/B switch. Try as I might, I couldn't discern any difference at all between the iPod and the CD. I tried the same with headphone out, and I could hear a tiny difference.
 
Unless the DAC is coloring the sound somehow, I don't see how an iPod can sound any better than the original CD playing in a good standalone CD player.
 
Jun 5, 2013 at 2:05 PM Post #17 of 44
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Originally Posted by thegrobe /img/forum/go_quote.gif
 
By best descriptor of the modded iPod (not external DAC) is that of looking through a dirty vs. a clean window.
There is a blacker background

Greenleaf, you have a couple of new ones to add to your list.
 
Jun 5, 2013 at 2:39 PM Post #18 of 44
Quote:
^^^ other then my ears.....
 
I'm just a vulnerable to the entire expectation/cost variable, as the next guy.  But my ears tell me its better.  The richness of the listening experience has gone up.  And I invite anyone to listen, and judge for themselves.
 
I would gladly argue that this DAC upgrade will do more for someone, then switching coding formats...

 
 
A better test would be to be able to determine the objective performance of both combinations which would remove the potential for human bias. The technical capability of the iPod Touch is documented and is okay but nothing special in absolute terms. There is a way that we can compare the two but it is a proxy measurement. You could set up each to play a segment of a file and record it back using an ADC into a computer. Then one could compare the differences between the two by comparing the wave forms. It only addresses one aspect but at least it would be a more or less direct comparison.
 
The number of times that sighted comparisons have proved utterly worthless is well documented, there are many cases where a listener has compared A and A and found vast differences because they believed the component was altered when it was not. This has been done for everything from power cables to amplifiers and protesting that you can isolate yourself from the biasing effects of knowing what you are listening to through some superhuman dissociative ability really does not hold water. This is not a dig at you it is just a matter of human psychology, at least a set of blind tests would be stronger evidence. 
 
Jun 5, 2013 at 3:03 PM Post #19 of 44
Quote:
 
The internal modifications for iPods are pretty straightforward and simple to understand, and the modification process does create an improvement. Basically, The signal is picked up directly from the DAC, routed through quality capacitors, and directly out of the iPod and into an external amplifier of your choice. This bypasses all of the insides of the iPod! You are basically picking up the pure signal from the DAC and hearing it, nothing more, nothing less. 
 
Your quote of "new and improved dac" is a bit off..the DAC is not improved, replaced or anything else in this modification. Just the ANALOG signal is picked up from the DAC and sent right out of the iPod. An external amp must be used. 
 

 
I'd assume you're saying that the internal components of the iPod will somehow degrade the signals and in turn have an adverse effect on audio quality. Please explain how this happens. Are you suggesting the iMod iPod is technically superior to the standard iPod?
 
Quote:
By best descriptor of the modded iPod (not external DAC) is that of looking through a dirty vs. a clean window. Compared to a stock 5/5.5G iPod - There is a blacker background, more extended treble (not muffled and rolled off as stock) and better clarity around instruments/notes.

This could be true, or it could also be a result of expectation bias (I'd take that the comparisons you've made between the iMod iPod and standard iPod were fully sighted). A simple ABX/blind test would help clarify if there is actually an audible sonic difference between the iMod iPod and standard iPod. And what do you mean by "black background"?
 
Jun 5, 2013 at 3:15 PM Post #21 of 44
It's good to see people trying to understand why improvements occur. But, it's always surprising when individuals who've never even listened to a piece of gear try to explain, a priori, why something just "can't" sound as good, i.e., the improvement in sound must be something that's imagined for some reason or another.  
 
Suggestion:  just go listen.
 
The improvement in using a high performance dac and amp to replace those inside an idevice is not subtle:  It's profound.  Just go listen.
 
Jun 5, 2013 at 3:31 PM Post #22 of 44
Quote:
 
 
A better test would be to be able to determine the objective performance of both combinations which would remove the potential for human bias. The technical capability of the iPod Touch is documented and is okay but nothing special in absolute terms. There is a way that we can compare the two but it is a proxy measurement. You could set up each to play a segment of a file and record it back using an ADC into a computer. Then one could compare the differences between the two by comparing the wave forms. It only addresses one aspect but at least it would be a more or less direct comparison.
 
The number of times that sighted comparisons have proved utterly worthless is well documented, there are many cases where a listener has compared A and A and found vast differences because they believed the component was altered when it was not. This has been done for everything from power cables to amplifiers and protesting that you can isolate yourself from the biasing effects of knowing what you are listening to through some superhuman dissociative ability really does not hold water. This is not a dig at you it is just a matter of human psychology, at least a set of blind tests would be stronger evidence. 

 
I suppose your idea would be great for sound science, but what would I gain from the experience.  I'm am, after all, shopping for my gear to please myself, and my ears.  And I already consider my purchase of the CLAS db a success.
 
FYI, if I was going to do a blind test with my gear.  I would suggest 4 listens; both balanced and unbalanced, and with and without the DAC.  More data points and all....
 
Jun 5, 2013 at 3:44 PM Post #23 of 44
Quote:
 
I suppose your idea would be great for sound science, but what would I gain from the experience.  I'm am, after all, shopping for my gear to please myself, and my ears.  And I already consider my purchase of the CLAS db a success.
 
 

 
But this is the Sound Science subforum where we want to try and sort out real from imagined. Perhaps the effect you mention is real perhaps it is in your mind which at $700 a pop would be an expensive bit of self-deception - why not learn which is which , it could be very liberating....
 
Jun 5, 2013 at 3:52 PM Post #24 of 44
Quote:
Unless the DAC is coloring the sound somehow, I don't see how an iPod can sound any better than the original CD playing in a good standalone CD player.

So then the quality of your CD player is to your ears, similar to the iPod. That Does not mean there is no room for improvement by a better source of some sort. There are better portable DAP's and better CD players. 
Quote:
Greenleaf, you have a couple of new ones to add to your list.

Cute. Glad I could help. 
Quote:
 
I'd assume you're saying that the internal components of the iPod will somehow degrade the signals and in turn have an adverse effect on audio quality. Please explain how this happens. Are you suggesting the iMod iPod is technically superior to the standard iPod?
 
This could be true, or it could also be a result of expectation bias (I'd take that the comparisons you've made between the iMod iPod and standard iPod were fully sighted). A simple ABX/blind test would help clarify if there is actually an audible sonic difference between the iMod iPod and standard iPod. And what do you mean by "black background"?

I suggest you pick up a Fiio "HS2 headphone switcher" I am able to compare two iPods > using two identical line out cables fabricated by me > HS2 > Leckerton UHA 6S MKII amp (any amp will do) > headphones. 
 
My wife finds it very irritating when I ask her to switch the inputs for me so I can blindly compare. I wouldn't be posting anything here if there wasn't a noticeable improvement. 
 
Of course, the better your headphones are, the better detailed, etc. you will find more differences between stock iPods and modded units. Or stock iPods and different DAC's. If you are expecting to hear a real difference using earbuds you are going to be disappointed. 
Quote:
It's good to see people trying to understand why improvements occur. But, it's always surprising when individuals who've never even listened to a piece of gear try to explain, a priori, why something just "can't" sound as good, i.e., the improvement in sound must be something that's imagined for some reason or another.  
 
Suggestion:  just go listen.
 
The improvement in using a high performance dac and amp to replace those inside an idevice is not subtle:  It's profound.  Just go listen.

Really, this is a great answer!
 
If you want to figure out if it sounds better, get a hold of some equipment and give it a listen. You can sit here all day and type, but that's not going to be the same as listening. Buy some stuff, try it out. If you don't like it sell it in the classifieds. Keep the stuff you like. Who knows? You may discover a combination that you love.
 
FYI- on a daily basis, I enjoy my 5G iPod touch straight out to my Heir CIEM's. No mods,, no amps, etc. It's a good setup. But is there room for improvement? Sure. That's why there are external DAC's, amps, etc. iMod at home, where bulk isn't an issue. 
 
Anyone who thinks there is no difference between DAC's should give a listen to a stock iPod vs. a desktop DAC, a replacement DAC, etc. Skyyyeman is right. The differences are profound. 
 
Jun 5, 2013 at 4:12 PM Post #25 of 44
I'd be interested in results from any testing that could be objectively done to determine if there was any difference between DACs that are technically audibly transparent.  I would think that any profound discovery would have more to do with perceived volume levels over any tangible results with regards to clarity or detail.  
 
I prefer to use an external DAC over an iPod or other source so that I can get a standard 2 V signal to my amp, if only for consistency with the rest of my equipment.
 
Jun 5, 2013 at 6:48 PM Post #26 of 44
Quote:
The improvement in using a high performance dac and amp to replace those inside an idevice is not subtle:  It's profound.  Just go listen.

 
I did a very careful comparison of a stock iPod classic against a highly regarded $900 standalone SACD/CD player and there was absolutely no difference. How much better could adding a DAC to the iPod be than the original CD played on a very nice home CD player?
 
Also, the specs of the DAC built into the iPod far exceeds the limits of human hearing. Perhaps better specs could be obtained, but they're going to be beyond the range of hearing. How could that be a "profound" difference?
 
Jun 5, 2013 at 6:53 PM Post #27 of 44
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So then the quality of your CD player is to your ears, similar to the iPod. That Does not mean there is no room for improvement by a better source of some sort. There are better portable DAP's and better CD players. 

No, maybe I wasn't clear enough... the sound of the iPod and the CD player weren't similar... they were *identical*, which is what I would expect for two players with signal to noise, frequency response and distortion ratings that exceed the limits of human hearing. Quite frankly, if they *didn't* sound identical, I would have gotten worried. Then I would have done a second test to see which one of them wasn't performing up to spec.
 
Even cheap DACs perform better than our ears. One might be better than another, but only in ways we can't hear. If I can't hear a difference, I don't care.
 
Jun 5, 2013 at 7:51 PM Post #28 of 44
As there has been no data to support any claims, I'll ask my original question again:
 
Quote:
What are the advantages of using an external DAC with an iPod?
 
I can't seem to detect any faults in the sound of my iPod (7th gen, running Rockbox). Am I not hearing correctly?

 
All I've really been getting back is "It's just better, you should try it".
 
If there is a substantial difference, please post the results of your tests. 
 
Jun 7, 2013 at 4:02 PM Post #29 of 44
Quote:
As there has been no data to support any claims, I'll ask my original question again:
 
 
All I've really been getting back is "It's just better, you should try it".
 
If there is a substantial difference, please post the results of your tests. 

 
Well, I do music listening as a hobby. Much as I imagine you do. I don't have any test equipment, analyzers, or a group of people running around in lab coats. So I'm afraid I can't be the one to provide you with any test results. 
 
I'm sorry that I can't help, but I tried to provide my insights the best I could. Just what I hear with my ears. 
 
Do you believe that all equipment sounds the same? Amps, headphones, cables, speakers? Or are you only skeptical of DAC's?
 
For the record, I am not anti-iPod. I use them all the time, direct out the headphone jack as I stated before. In fact, if your iPod sounds perfect for you with no room for improvement then that's great. Just be satisfied and go onto other things in life. But if this is the case, why insist that others prove to you otherwise?
 
I find it really hard to believe that anyone could think that different equipment does NOT sound different. To me, the differences are more than subtle. Anyone who does not believe that a DAC makes any difference is welcome to come by and do a blind compare of my desktop DAC's (Audio-GD SA-1.32 and CEntrance DACmini) to a stock iPod, all the rest of the chain identical. The differences are vast. If you don't hear a difference I would be very surprised. Then I would suggest that you are in the wrong hobby. 
 
On another note, if we did such a blind comparison and you did indeed claim to hear absolutely no difference, how do we prove that you are being honest in your answers? The "proof" you insist on others providing (that there is a difference) can't be reciprocated or countered fairly if you are biased and insistent that there is NO difference. So, just as you are demanding proof that there is a difference between DAC's, I hereby request test results and data that proves there is no difference. Please post the results of your tests.
 
I will bow out of this thread, since I'm out of my element. But I will leave you with this: different equipment sounds different. That is a fact. I don't know any other way to prove it other than to listen. (yes, blind comparisons) I have several different DAP's, amps, cables, desktop DAC's, headphones. Different combinations sound different. I'm not saying it's always "better" or "worse" most of the time it's just preference. Some combos sound better with certain genres, etc. 
 
I mean no ill will, but I just don't know how to help you hear what the differences are between equipment if you refuse to listen to the equipment. I don't see any other way.
 
Peace. Happy listening
 
Jun 7, 2013 at 5:48 PM Post #30 of 44
I find it really hard to believe that anyone could think that different equipment does NOT sound different.


Well, I'm not a scientist in a lab coat, but I'm very picky about my equipment. Whenever I get a new player or amp, I rack it up next to all my other players or amps and compare. I've had about ten CD players and about as many iPods, iPads and iPhones. I've had four amps. Every single one of them sounded exactly the same when I took the trouble to balance the volume level and do direct A/B switching between them.

I've spent months precisely equalizing my speaker system. If I get a new amp or CD player, I don't want to have to go back to square one and balance all over again because of coloration. If I ever end up buying something that is colored and sounds different from all my other players and amps, it's going straight back to the store.

Good equipment shouldn't have a sound. It should just present the music exactly as it is recorded. I wish speakers and headphones were consistent like electronics are.
 

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