Topic Tag: Universal 6or12SN7 Preamp Search for: Home › Forums › Topic Tag: Universal 6or12SN7 Preamp Viewing topic 1 (of 1 total) Topic Voices Posts Last Post How to test universal preamp Started by: Dinx in: Forum 2 8 1 year, 4 months ago Dinx Viewing topic 1 (of 1 total)