For me the number one criteria for buying an iPod is audio quality. Some people will go for looks, size, or battery life, but for me it’s simply a matter of which iPod sounds the best – not just through the headphones but also into my stereo.
This article discusses the reasons for the difference in quality of the sound output of the various models of iPods and iPhones, which iPod sounds the best, and why.
Firstly, the Best iPods:
1st place: 5.5th Gen Classic
First place goes to the 5.5th Gen Enhanced iPod – the last iPod released in the 5th Generation iPod family. Be careful not to confuse this with the 6th generation ipod called Apple iPod ‘Classic’ which looks almost identical. The 6th Generation has the aluminium front. The 5th Gen family has a plastic front case.
2nd place: 5th Gen Classic
A very close second place to the rest of the 5th Gen classic family. Looks identical to the 5.5th Gen. Read this article for how to tell the 5 and the 5.5 apart.
3rd place: 4th Gen Classic
Third place goes to the 4th Generation iPod family including iPod photo, iPod colour and U2 edition iPod.
4th place: 1st Gen Nano
Now keep in mind that the 1st Generation Nano also has flash memory instead of a hard drive, which makes it a great contender for the best overall second hand iPod. In fact the price of these iPods has been rising over the years and you will do well if you can find one for under $150 second hand!
Why is there a difference?
1. The Audio Chip that is used – Cirrus iPod vs Wolfson
There are two main things that contribute to the sound quality of an ipod. One is the audio chip that is used, the other are the components along the audio path from the audio chip to the headphone jack – a mixture of op-amps, capacitors, resistors and inductors.
The iPods I like the best seem to be those that use the Audio chips from the Scottish company Wolfson. When I detected this difference I didn’t not know what a Wolfson chip was, but I could hear a difference and so I did some research. It turns out that my two favourite iPods – my Nano and my 4th Gen iPod both have a Wolfson chip in them. The iPhone 3Gs does not.
2. Other components.
The sound quality of course depends on more than just the chip that is used, so it’s not just about which chip is in the iPod. My Shuffle model A1204 (non-wolfson) sounds great, as does the iPhone 4S. I have an iPhone 4S and even though it doesn’t have a Wolfson chip it sounds incredible.
Red Wine Audio offer mods of the 4th gen and 5th gen iPods where they will replace the output section of the iPod with high quality Black Gate NX-Hi-Q capacitors. According to onheadphones.com the output audio quality rivals that of $1500 CD-players, with improved bass response and clear high end. (There is an excellent forum here on how to do the mod yourself!)
If you want the best possible audio quality, try and get hold of one of the fifth generation iPods – model number A1136. This includes the iPod 5G, iPod U2 5G, iPod 5th Gen enhanced and iPod 5th Gen with video.
The 5.5th Gen ‘Enhanced’ is hart to spot as it has exactly the same model number as the 5th Gen iPod. (A1136). The way to tell the ‘Enhanced’ apart is that it has a ‘Search’ option in the software. I have one – it sounds great.
The only thing better than that is to get a 4G or 5G modded with the Red Wine Mod!
iPod Classic vs iPod 5th Gen
Here is a great article by Marc Heijligers examining the iPod Classic against the iPod 5th Generation. [Thanks to Clive who has found this archived copy of this article.] The article was also quoted here. Marc’s homepage is here. I have made a pdf copy of it here in case it goes missing again. Here is a quote from the article:
“I noticed that the 6G sounds precise, crisp, but lacks 3D image and has an electronic haze to the sound. At first, this might sound like an improvement (crisp, detailed), but when listening more carefully and for longer times, it becomes fatiguing after a while. The 5G sounds less precise, but its timbre contains more harmonic information and sounds less electronic. For me, the 5G is closer to how I experience acoustic music in real life, and for me is the better sounding device overall.”
He then goes on to do some measurements to back up his findings.
This was his conclusion:
“From these measurements it is obvious that the new audio circuit of the iPod Classic is badly engineered compared to the iPod Video:
– Treble has a slight uplift.
– The group delay is not linear over the frequency range.
– There is significant intermodulation distortion with a 22.1kHz component.
The measurements show a correlation with the things I hear, but from a pure scientific perspective the cause-consequence is not determined by these measurements. The measurements show some flawed behavior of the audio circuitry, which so-far is the only thing that can be concluded without any doubt.
Overall, the 6G overall sound performance is disappointing to me, especially considering the well-sounding 5G. Does it mean you shouldn’t buy an iPod 6G? The way the change of sound quality is perceived will vary per individual. Therefore I recommend you to judge the 6G individually, and don’t let ourself be guided by my opinion, or some measurement graphs.”
This test shows iPhone 4S has better specs the iPod Classic 6G and better than iPad 2, but I can’t’ find any direct comparison with the 5.5G iPod.
Which iPods have a Wolfson audio chip?
iPod Touch 1G (WM8758BG)
iPod mini (Wolfson 8731?)
In summary, all the early iPods up to 5G Classic used Wolfson chips.
Which iPods have a Cirrus Audio Chip?
ipod ‘Classic’ 1G , 2G & 3G (CS42L55) (These are also known as 6th 7th and 8th gen iPod)
iPod Touch 2G (possibly CS42L58)
iPod Shuffle 4th Gen (CLI1544C0)
Other notes on DAC chips:
Headphiles is compiling a list of the various DAC’s used in various devices here.
Cambridge Audio and Harman Kardon use Wolfson DAC chips in their CD players. Pioneer, NAD and Onkyo use wolfson in some of their CD players. Marantz use Cirrus Range. It’s not just about the chip – the other audio components will make a difference too.
Why I wrote this article.
Back in 2010 I was driving along listening to U2 on my iPhone 3GS. I wanted to change to a different song that was on my nano and instantly I noticed the sound quality was much better on the iPod nano than on the more expensive iPhone. I have since done some side-by-side tests using the same song on the iPhone 3GS and the iPod nano and the iPod Nano definitely has better quality audio. It clearly has a better bass response and is not so harsh in the high-end. So not all iPods are same, this got me wondering why. I have done some investigation, and some side by side tests, and there is a lot of difference between the various iPods.
Keep in mind that listening tests are personal – some people like huge bass, some like a warmth. So some people will prefer to listen to something that technically is less quality audio, but has huge bass.
I like clarity. I like to feel like I am there. I am also sensitive to any slight increase in the midrange or treble that will make the music sound harsh – especially over long periods, and I like to hear the very low bass, I’m not a bass head who wants it loud, but I want it to be there. So I am talking about purity of sound in this article.
This article was first written in 2010, and Apple keeps improving the audio quality with every iPod released, but I think these results still stand. Check out this thread for some other raves about the 5.5G iPod compared to the later models. There will always be new models coming out – keep an eye on head-fi forums and so on for reviews.
2011:Recently the 7th Generation Classic has been released and some people prefer the 7 to the 5.5. There’s a great debate about the 5.5G vs 7G here and here. It seems the 7G is more accurate and precise, however the 5.5 feels warmer.
2011: It’s rumoured that with the iPhone 5 Apple will be returning to the Wolfson chips, but we’ll see! (Note: The iPhone 5 was been released and they didn’t, same for iPhone 6).
2015: Apple have released iPhone 6, no wolfson but you can still use the lightning to 30 pin dock adapter.
If you are after good audio in an iPod the older ones are the best. (especially the 4th and 5.5th Gen classic era)
The Best iPods:
iPod 5.5G Enhanced (wolfson WM8758)
iPod 5G (wolfson WM8758)
iPod 4G (wolfson WM8975)
iPod nano 1G and 2G (wolfson 8975).
(iPod Classic 7G might fit in here, see discussion here.)