I think you're mainly hearing tonal balance differences between components. The Krell/ARC tonal balance may have complemented the ProAc better than the Rowland/Wadia for your taste. In my experience nobody makes a truly neutral component. In order to achieve an overall neutral sound you need to have some components or cables that are slightly bright and some that are slightly warm, though the closer to neutral your components are, the easier it is to match them.
I would guess that your system sounds a little on the warm side now and you actually prefer something on the detailed/analytical side. The Siltech cables I've heard are among the brightest available so I'm not sure if you'll achieve much by switching cables. Do you still have access to the Krell? If so, try the Wadia with it. Also try the preamp outputs of the Krell run to the Rowland. This will help narrow it down to an amp preference or a CD player preference. I think it's fair to say the CD3 is regarded as a better player than the 830 and the soundstaging you heard with it was due to its higher resolution. Also, the volume control of the Wadia is known to cause a loss of resolution at its lower settings. A preamp might help things. The tonality difference you heard is likely to be the difference between the amplifiers. Try lots of combinations. Eventually you'll develop a knack for matching systems to get the sound you want.
I would guess that your system sounds a little on the warm side now and you actually prefer something on the detailed/analytical side. The Siltech cables I've heard are among the brightest available so I'm not sure if you'll achieve much by switching cables. Do you still have access to the Krell? If so, try the Wadia with it. Also try the preamp outputs of the Krell run to the Rowland. This will help narrow it down to an amp preference or a CD player preference. I think it's fair to say the CD3 is regarded as a better player than the 830 and the soundstaging you heard with it was due to its higher resolution. Also, the volume control of the Wadia is known to cause a loss of resolution at its lower settings. A preamp might help things. The tonality difference you heard is likely to be the difference between the amplifiers. Try lots of combinations. Eventually you'll develop a knack for matching systems to get the sound you want.