SPL Charisma 9733 - Tubes?

Hey, I recently bought an SPL Charisma Model 9733 (2 Channels) from Ebay.
And I would like to know, if anybody here has any experience with changing the tubes of it. Not so much "how to" but which type of tubes it accepts. I read somewhere on gearslutz, that it has to be a certain type of tubes.
So, if anybody has an Charisma and changed the tubes in it, I would really appreciate some infos.

30 second search brings this up:

Gaining access to the insides of the Charisma involves removing 12 short self-tapping screws from the steel lid. A single mother board carries the encapsulated mains transformer and power supply circuitry on the right-hand side, and in a neat row across the centre of this high-quality PCB are eight E83CC valves. Immediately in front of these are eight vertically-mounted daughter boards carrying the front panel controls and most of the electronics for each channel. The rear-panel connectors all mount directly to the mother board.

The E83CC is effectively an upgraded version of the better-known ECC83 double-triode valve, with higher gain, improved high-frequency capabilities and more effective internal screening.

RTFM, big dawg. There are only 2 in the 2 channel version, as this is describing the 8 channel unit. Dont go buying 8 E83CC's, lmfao.