The Chinese 12AU7 tube is low in microphonics. The US 12AU7 is a classic tube with a large plate. Our Low Noise tubes are a superior tube especially tested for today’s quality line stages. Only 30% of the tubes we test perform well enough to be considered Low Noise. 12AU7 - LN$45.00 Need assistance? Email info@tubeaudiostore.com or call 805-687-2236. Photography by VisionQuest Photography