Yes Sophia are just rebranded TJ tubes and have a bad rap for reliability. I have only had a few tubes fail in my audio life and they have all been Sophia/TJ. I also have numerous friends that have had problems with Sophia 300B. Buyer beware.
2019 300B tubes that are worth the money?
OK, I'm not a super rich audiophile that has unlimited money to blow. I have a pair of Cary 300 CAD300-SE monoblocks i bought used that currently have a pair of TJ/Full music tubes in them. I am, overall, very happy with the sound. So does anyone have a strong opinion that any of the $1000 a pair current production 300b tubes are really worth the money over my $300 pair? Would my money be better spend on a needle upgrade for my turntable? :-)