JAH wrote:You clearly implied the circuitry doesn't add any coloration to the sound. Can you prove this?
Like the OP said, this "circuitry" is just an anti-aliasing filter
outside of the audio region. Just learn about what anti-aliasing filters are and how they work:

Airyck wrote:EQing and filtering at any frequency effects all of the frequencies except in the case of linear phase which is not possible in hardware alone.
So in the case of an anti aliasing filter copied from the 3000 to the Ren it would impart the sample phase smearing that was caused in the original 3000 which does change the sound, however slight.
You can think of EQing or filtering on a stretched out rubber band.
When you press down at any point of the rubber band it stretches the entire rubber band but more so at the cutoff frequency.
So even seemingly insignificant lowpass anti-aliasing filters can cause changes in the sound.
While that sounds nice in theory and would certainly help to reduce buyer's remorse for Ren owners if it was really the case, the reality is that listening tests will not show any audible difference from what kind of anti-aliasing filter is used.
For example, this test shows that the impulse response "smearing" has no audible effect: "If energy smear is a real and significant effect, then these seven very different filters should have made obviously different imprints on the sound quality of the test tracks. But the listening results, described in the sidebar, indicate that the sonic disparities between the filtered tracks and the 24/96 originals were very difficult to pin down."
http://www.stereophile.com/reference/10 ... index.html