is it simply me, or does the iPhone3GS sound better than my iPhone 4?

I have no direct idea (I own the 3GS but have not heard the 4) but I am concerned based on what I have read. The iPhone 4 is using the Cirrus Logic audio codec. This was identified by a web site that broke it down. If this is the same CL codec used in the Classic, it is worse than the 3GS.

On the other hand, I have heard conflicting stories regarding which DAC is used in the iPhone 3GS. Anyway the issue is not just branding but which DAC and how is it implemented. I hope that others will offer opinions on how the iPhone 3GS and 4 compare.

Do you happen to find big a big difference between the 2009 Classic and the 3GS line outs (DAC's) ?
 

I am going to eat some crow here. As it turns out, I am not pleased with the SQ of the Classic. It is not a good source for the Stepdance IMHO.  Don't get me wrong: all iPods sound better than anything that we deserve to be able to slip into our pockets and that includes the Classic. However, in comparative terms, the Classic is a material and meaningful step down from the iPhone 3GS, both headphone out as well as line out. It's too bad because I love the ability to carry all of my music with me.  I am taking the Classic back and returning to using my iPhone 3GS as the Stepdance source.

I was rejecting all the Classic naysayers but it turned out that everything that they were writing some two years ago (with measurements etc.) was and remains pretty much true. The Classic is a bit brittle and fatiguing in the treble and somehow the sound just doesn't fill out. It sounded empty compared to the iPhone - lacking in 3D imaging. And all of this was obvious with just my Triple-fi's. My ES5s aren't back yet. I spent two days going back and forth between the Classic and the iPhone, both with and without the Stepdance. I really realy wanted the Classic just to sound as good as the iPhone but it doesn't.

iPhone 3GS + Stepdance > iPhone 3GS > Classic 7G + Stepdance > Classic 7G.

One caveat: my Stepdance is still not close to being fully burned in. But as they say: the trend is your friend.

Just curious, how far is the 3GS from the iMod in your opinion? Are you actually using the 3GS more?

I found my imod to be quite a bit more detailed and more neutral than my iphone 3GS. Of course the iMod is quite dependant on the amp you pair with it but using both as line out only, I found these differences quite noticable. Ipod with more bass and less refinement. Imod with ALOT more soundstage and in short, sounding more hi-end. Better separation, decay, detail and transparency. A very clean, quality source to be colored (or not) by your amp of choice. The iphone 3GS adds a bit too much color of its own (ipod house sound) but when using headphone out thats ok IMO. Its actually pretty impressive as a stand alone unit IMO.

Just IMO, the iphone 4 doesn't sound better or worse than the 3GS but certainly different. Out of my IEM's, I noticed a reduction in treble(little less sparkly), but with a slightly better soundstage. Also seems to have a stronger amp in place as well.