Cheap Chinees, such as TJ's or other's have problems to keep bias at the level, they just don't, so, if I were you, I would buy from trusty source and the high quality only. I have read a lot about 300B's and many of them just dont have the quality level, however they may sound pretty good, but like many already said, if they will be dead in a short time, why bother?
Go for EML's or KR's, but tubular, earlier production type. I own a pair and they are very good.
Go for EML's or KR's, but tubular, earlier production type. I own a pair and they are very good.

