The Lineal is a neutral Volume-Booster based on the EH Linear Power Booster. It boosts signal about 25dB, without changing the sound too much. It needs very few parts, so it is perfect for beginners.
Installationguide: Install guide
Schematic and pcb: Lineal schematic and pcb
Wiring using a battery clip: Alternative Wiring
Partslist (BOM): Lineal parts