Do all 6550 based tube amps sound the same?

I'll second Elevick's statement, they don't sound the same. Even 6550 tubes themselves from different manufacturers have different sonics. Plus, any amp utilizing 6550's in the output stage probably has tubes in the input and driver stages as well - further factors in sonic signature. There are SO many variables in the sonics of tube amps...

The CJ premier twelves have a naturally warmer, more easy going sound than ARC amps and more than most amps actually. My choice would depend on other gear in the system.

The fellow asked a good question, the truth of the matter is, yes most 6550 tube based amps share a common sonic signature. Do they sound the same, no, as stated in other posts different input and driver tubes as well as brands will affect the sound. Viridian, your answer is sarcastic and adds nothing to the tread. By the way, I have built tube amps since the 1960s and have some experience in this matter

robert8409,
Just curious, what is the formal defenition of "sonic signature", as I might not be using is properly. Thanks :-)

ps - notice how Viridian pulled his post?