Sophia Electric did have supplied the best vintage NOS driver tubes for Baby Amplifier. So save your money for a pair of good speakers or a good cd player/DAC.
Yes, there is WE 396A available at $100+ a pair, but the amplifier was design and voiced with GE and 6P1T for best sound, why mess up the factory carefully voiced great sound by looking for wild tubes?!
The Baby Amplifiers are something special! Not those mass produced amps could compare. Those who have compared would know.
WA