I forgot, whats the diff between a kt88 and 6550?

[Young Angus]

My ENGL Savage 120 head is 120watts and has two 6550 and an ecc83 as the power section. But i dont think they are regular 6550's (if there is such a thing as irregular ones) because the online manual says that the power section is made up of an ecc83 and two KT88's.

Robert.S also said how his jcm800 has four 6550 tubes as the power section and its only 100watts. Same goes for the marshall zak wylde signiature jcm800 head.

So is there a difference between the 6550's marshall are using and the KT88's that ENGL are using, and is this difference the reason why ENGL can squeeze 120 watts from just two KT88's?

I am very confused

 

[Young Angus]

bump

 

[Steve_R]

Here is some info from Rivera
6550-kt88

 

[mrid]

The GEC designed KT88's are capable of pushing 50 watts per and so are the Tung Sol designed 6550's. The KT88 just has higher ratings (plate, screen, etc...).