Wolfson Audio chip VS Cirrus Audio chip

A lot of people ask me why I still prefer to listen to music on my 5th generation iPod over anything else. The answer is simple, it just sounds better! But why does it sound better?Here's a great quote from an article I have been referring my customers to for some time now:

"Back in 2010 I was driving along listening to U2 on my iPhone 3GS. I wanted to change to a different song that was not on my iPhone so I plugged in my first generation nano and instantly I noticed the sound quality was much better on the iPod nano than on the more expensive iPhone. This led me to do some listening tests using the same song.  The iPod nano definitely had better quality audio. It had a better bass response and was not so harsh in the high-end. So not all iPods are same. This got me wondering why. IT turns out that there are different audio chips used in different iPods. There are also different other parts, but I think the main difference comes form the Audio chips that are used." [source]

I had a similar experience with my music. When I got my first iPhone 3GS, I was excited to have my phone and music all in one place. However, I quickly realized that things just didn't sound the same as they did on my iPod. After some research, I found that Apple had switched from the third party, higher end Wolfson chips when they released the 6th generation iPod classics. I had been using my 5th gen iPod since I first bought it back in 2006, so the iPhone 3GS was my first real experience with the new chip.

“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.” [source]

Although this may not be a deal breaker for the casual listener, but for anyone who listens to their music a lot (for me it's what I do on my bus ride to work), the Wolfson seems to produce better sounding music, that is more pleasing to the ear. Bass seems more natural, and overall the music sounds less "digital". 

Which iPods have a Wolfson audio chip?

iPod 1G & 2G (WM8721), 3G (WM8731),  4G(WM8975),  5G  (WM87588G) and 5.5G (WM87588G)

iPod nano 1G (WM8975G), 2G (WM8975), 3G (WM1870)*

iPod Touch 1G (WM8758BG)

iPod mini (Wolfson 8731?)

iPhone (WM8758BG) and the iPhone 3G (WM6180).

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 nano 4G (CS42L58), 5G (CLI1480A), 6G (CLI1544C0)

iPod Touch 2G (possibly CS42L58)

iPhone 3GS (CS41L61) and 4(338S0589), 4S (338S0987)

iPod Shuffle 4th Gen (CLI1544C0)

There are many great articles online that go more in depth, but I wanted to touch on things a bit and TLDR a little bit. In my experience, the Wolfson chips produce better sound, and because of this the 5th generation video iPods actually seem to sell for a higher price on eBay than the 6th generation classics.

What's your experience with the Wolfson VS Cirrus chips? Can you hear the difference?