Best audio quality - Apple iTouch vs iPod Classic

Hello all,
Any first hand thoughts / comments on which current Apple iPOD family product has the better DAC / overall music quality? (iPod classic / iTouch / iPhone)

I do not have an external DAC so the Wadia 170 iTransport is not an option at this point.

I've ripped a couple of red book CDs to AIFF and copied them to my iPhone, and I'm impressed with the audio quality when compared to my Oppo. BTW Each song on Diana Krall's "Live in Paris" is about 60 megabytes.

Although using an iPOD family device will not replace my CDP or TT, will be yet another source, when convenience is priority.

Regards,