“Changed my stock tubes with Telefunken 12AU7. WOW… it smooths up upper freq. and vocal.” Read
“… generally speaking all the Telefunken 12A family tubes I’ve heard (‘X7s, ‘T7s, ‘U7s) are a bit bright, thin and airy sounding. ” Read
Tube Maze
Guides and reviews of vacuum tubes and audio equipment
The Telefunken 12AU7 Smooth Plate is a polarizing icon in the audiophile world, often sparking a “love it or hate it” debate among enthusiasts. On one hand, critics dismiss it for a sound signature they find thin and overly airy. On the other, devotees praise it for that exact same quality, describing the output as gentle, ethereal, and undeniably musical.
While it may not be a universal “workhorse” tube for every genre, when paired with the right material, it creates a unique “Telefunken magic” that is hard to replicate. This magic is rooted in its incredible sense of airiness, which mimics a subtle, natural reverberation following each note. While technical purists might argue that this lack of clinical precision is a flaw, most listeners find that it significantly expands the soundstage, prioritizing pure enjoyment over raw accuracy.
Historically, Telefunken eventually transitioned from the smooth plate design to ribbed plates for purely practical reasons. The smooth plates were more susceptible to microphonics—physical vibrations that can introduce unwanted noise into the signal. By adding ribs to the plates, Telefunken increased the structural integrity and stiffness of the internal elements, making the tubes more durable and less prone to ringing in high-gain or high-vibration environments.
Final Verdict: If you value a massive, atmospheric soundstage and a touch of vintage “soul” over sterile precision, this tube is Highly Recommended.