Usually Krell gear has three red switches inside. They are easy to access. Just remove top cover and you will see them close to power section (sometimes the switches are "hidden" with glued black plastic covers on top of the swithes. .Just take those away). In all my Krell gear (about 25 units) the settings of those switches shall be 2-2-2 for 240 Volt. I do not have the KAV 280cdp but the KPS30i cd player and it has those three red switches inside. The setting 2-2-1 is usually for US standard, 120 Volts.
I live in Sweden where we have 230 Volt, 50 Hz as standard. I have bought several poweramps from the US and never had any problems changing the voltage from 120 to 240 Volts. The only problem I have faced was with a couple of Krell FPB 300cx poweramps. They are locked to 60 Hz and needs a new IC to accept 50 Hz. Those wonderful Krellamps are the only ones of all Krell gear I have that needed the IC change. Take you player with you to Europe!!! There are plenty of Krellservice places in Europe. Some certified by Krell, some not. Look for the certified ones (of course). Good Luck! Mikael Sweden
Edit: You can easily change the switches yourself but then you must be 100% sure that 2-2-2 is the correct setting for 240 volts for your KAV 280cdp If you have Facebook you can join the group "Krell owners and enthusiasts group". It is a serious group where members and some Krell employees and retired Krell employees answers questions. Highly recommended.