(12 votes, average: 3.83 out of 5)
Loading...” linear, clean but just a bit clinical and hard sounding. Good transparency and detail.” Read
“Silky sweet high, extremly detailed mid but a litle bass shy. See trough, great soundstage wide and deep without any sign of agression. ” Read
” It was polite, smooth and accurate.” Read
“They’re on the tonally “neutral” side, with excellent clarity and good extension top to bottom.” Read
While there are plenty of glowing reports online for the RFT 12AU7 Angled Getter, my personal experience was a bit more grounded. In a preamp stage, the tube offers a notably airy presentation, but it lacks the surgical precision and distinct instrument separation found in its more expensive counterparts. The midrange, while clear, doesn’t quite capture the “sweetness” that defines the high-end European standard.
The most significant caveat comes when pairing this tube with headphone amplifiers, such as the Bottlehead Crack. In these setups, the RFT can become fatiguingly bright, making it difficult to enjoy for long listening sessions. It is an excellent choice for taming “dark” vintage systems that need a lift in clarity, but in modern, neutral systems, it risks pushing the high end into the territory of clinical sharpness.
The story of the RFT (Rundfunk- und Fernmelde-Technik) is rooted in the post-WWII division of Germany. RFT was not a single company but a trade association of various nationalized electronics firms in East Germany (GDR), primarily centered around the Neuhaus and Erfurt plants.
During the Cold War, there was a surprising amount of cooperation across the Iron Curtain. Because RFT labor and production costs were lower, Western giants like Telefunken and Siemens frequently contracted RFT to manufacture tubes for them. These tubes were often “rebranded”—manufactured in East Germany but stamped with the prestigious Telefunken or Siemens logos for sale in Western markets. While they share a lineage and sometimes similar internal structures, the RFT-branded versions are generally considered the “blue-collar” cousins: reliable and clear, but often lacking the premium materials and rigorous quality control that gave Telefunken its legendary “diamond-bottom” smoothness and Siemens its ultra-low noise floor.
Final Verdict: At approximately $10 per tube, the RFT 12AU7 is a low-risk experiment. It is a fantastic “corrective” tube for muffled speakers, but those seeking the refined liquid mids of a true Telefunken may find it a bit too unrefined.