The G9 is a two-channel, discrete, transformer-balanced, tube preamp based on the Gyratek IX. Gyraf’s website offers free schematics, instructions and PCB layouts.
Images courtesy of Gyraf Audio
- High-pass filter with “High” and “Low” settings
- Output trim pot
- Switchable line/DI input
- Solid-state power supply
- 20€ for PCB
Deals on suitable tubes via eBay: