The RCA input impedance of the XA30.5 is 20k. Pass originally listed it at 15k but it was tested at 20k and Pass has changed that spec on some of its literature.
On preamp output impedance: remember the spec is the "average". Just like an 8 ohm speaker is hardly ever 8 ohms across the spectrum (it could vary from 2 to 30 ohms). Some pres will be many times more than its rated spec especially at the low or high end. Try and find those specs when you go hunting.
On preamp output impedance: remember the spec is the "average". Just like an 8 ohm speaker is hardly ever 8 ohms across the spectrum (it could vary from 2 to 30 ohms). Some pres will be many times more than its rated spec especially at the low or high end. Try and find those specs when you go hunting.