If you are looking at a 1272 schematic for a DIY build, pay close attention to these sections:
According to official BAE Audio documentation , a standard 1272 module follows these specs: +/- 0.5dB 20Hz-20kHz. Mic Input Impedance: Switchable between 300 or 1200 ohms. Power Requirements: 80mA @ +24VDC.
If you examine an actual schematic, look for:
If you have a Neve 1073 schematic, you already have 90% of a 1272. The 1272 simply omits the mic pre input transformer and the first two gain stages.
The 1272's performance and "fat" sonic character are built around a few critical components: The BA283 (or BA183) Gain Card : This is the heart of the module, containing only six transistors . It provides the Class A gain and output drive. 10468 Input Transformer
Because original modules have become nearly impossible to find, a massive DIY and boutique market has emerged. Brent Averill 1272 and 1073 preamp the same - Gearspace
