A 6BQ7A tube is equivalent to types6BZ7 &6BS8, and is slightly different, but normally replaceable with a6BQ7 tube.
2 VINTAGE NEW OLD STOCK PHILIPS MINIWATT TUBES. BOTH TUBES HAVE MATCHING CODE DATES. MADE IN AUSTRALIA. GREAT PRE AMP TUBES AMONGST THEIR USES. BOTH TESTED AND READY TO USE. ANY ISSUES YOU MAY RETURN THEM FOR A FULL REFUND.