The classic "1272 mod" involves:
A single-ended common-emitter stage with active load (Q4). This generates most of the open-loop gain. Neve 1272 Schematic
The Neve 1272 is not a microphone preamplifier by original design, but rather the stage borrowed from the legendary Neve 1073 mic pre/eq module. In the 1073, the signal path consists of three gain stages: Neve 1272 Schematic