Sakahara,
Why not replace that 'jittery' TI chip [PCM270X] then, or is that what the ASI mod does?
Ach, can't do that! the whole 170i is built around the PCM270X IC. You remove this IC & you basically have nothing!
I believe that the better thing to do is to re-clock the digital signal. You can use more modest re-clockers such as Monarchy DIP, GW Labs, Genesis Digital Lens. Some of these are available used.
No, the ASi mods are quite extensive but it does not replace the PCM270X IC. The ASi mods offer upgrading caps & voltage regulators, replacing the clock with a Superclock, chassis damping, better quality connectors, etc, etc. You can read more on their website. I don't have the address handy but Google it.
Why did Wadia use this chip (savings) if it's known to be 'jittery'?
yes, I'm sure that the end cost must have played a part in selecting this commodity IC. The 170i is a $380 docking station for a $250 iPod. The prices of both items match - people buying the iPod would consider the 170i as a mate. What if the 170i cost $1250 (like the Pace Car 2) - would an iPod buyer consider it as favourably as he would a $380 170i? Some would but most will not!
That Weiss Minerva FW DAC looks cool
yup! have a couple friends that own it. this DAC can go all the way to 192KHz so it can playback standard redbook & upsampled redbook. Seems to have all the flexibility that one would need today. It's the FireWire connection that allows it to support 192KHz.