Ok I think I'm understanding this

>So, look for new production 7027s (NOS cost a mint<

Most of the so called new 7027's I've read about are described as 6l6's with extra pins.




>or look at 6550/KT88s<

It's my understanding at this point that the 6550's are like an industrial version of the KT88's. A bit more durable but lacking dependability. THe KT's have been also described as having a better bass quailty...but that might just be subjective pontifcation from snobs.

So I need a quad of something...one or the other. I'll just make sure they are good ones.