Luxman SQ38FD tubes replacement.

Do i need to correct the bias of the tubes when replacing the new tubes on Luxman SQ38FD?
Very cool vintage amp! Do you have a manual? If there is bias setting then yes you should bias new power tubes. So it uses 50CA10 tubes? Is it easy finding them? Here is the amps page on hifi engine you they have a schematic of the amp posted but you need to sign up to view it.
Hi Jond, the tubes are still available on eBay but the price is a bit high. I'm thinking to swap those power tubes (50CA10) to KT88 or EL34. Can anyone recommend me how to do?