I'm looking for the way to re-use my used tubes. Everybody who uses a vacuum tube pre-amplifier should try this project.
1. Those 2 tubes and parts that beside the transformer are using for the regluator, and the LM317 is mount on a 2" x 1" heatsink.
2. The 6FQ7 and ECC83 that use in this regluator are used tubes from the Mini 7 Preamplifier and the Hybrid Power Amplifier.
3. Those twin triodes are parallel in work.