A or fully complementary pair of transistors.
For the DIY audio enthusiast, the vintage gear restorer, or the modern 500-series builder, the is not just a circuit diagram—it is a treasure map. It leads to the holy grail of "warm," "punchy," and "musical" analog tone. Neve 1272 Schematic
If you are reading a 1272 schematic to build a clone, pay attention to these critical points: A or fully complementary pair of transistors