Loading... Please wait...Radiotechnique 12AU7 - Made in France. This is the earliest version of this tube, period. There was a middle version that we had available, but did not dig as much. In fact there are four versions that I have in stock. Only this version, and the 1965 version are cool in my book. This one is made from 1956 to 1960, early getter, small plate. Sound wonderful, and seem to last.
Radiotechnique was the French arm of Philips Holland, and this tube shares many sonic characteristics with its Dutch cousins, most notably it's holographic soundstaging and open, airy top end. For more info on the Philips factories, click here. This tube blooms more and has a decided 3d effect. The top end is extended but not bright. Bass is fabulous.
Platinum grade - The best of the best. Lowest noise and microphony with the tightest triode balance we have available. This is typically 10% or tighter, but may be higher depending on available stock.
Gold grade - Low noise and microphonics with a triode balance typically between 15% and 20%, but may be higher depending on available stock.
Driver grade - Not available at this time. Don't be a cheapskate. Get the best stuff.
Click here for a more in depth discussion on how we grade tubes.
Posted by Jerry
Greetings Kevin, One of your staff recommended this tube (1956 Radiotechnicque 12AU7) for my 303-300 after discussing my system with me...and it''s an unbelievable home run. The upper register clarity and "liveness" of this tube coupled with great bass and very low microphony make it an amazing listen. Huge improvement over the stock EH''s in the Cary. Huge!!! Highly recommended. Thanks!
Posted by PeterG Australia
Ive tried 6 other tubes for my PrimaLuna Dialogue 3 preamp and when I put these in I knew id hit paydirt !
It combines detail, clarity, top end extension, solid base, 3D midrange and a balanced overall tonal quality .. its all there ... nothings missing .. IMHO and in my setup of course.
Its not a warm tube like the Mullard .. id describe it as accurate.
I have solid state monoblock power amps and this tube preserves the slam and transient response that I love .. but adds the soul that solid state cant capture.
Jaw dropping stuff .. Enjoy
Most of you already know that Upscale Audio is the premier destination for expertise and availability of vacuum tubes for high-end audio equipment. So when we offer servies and options, you can be guaranteed that it represents a significant investment of research and capital, and that the end result will greatly enhance your listening experience.
Upscale has contracted with the foremost company involved in this technology, 300 Below, to treat our most popular tubes. Other tubes will be added as time allows, but it is a time consuming proccess. Our intention is to have most stocks Cryogenically treated before we even test them.

Of course, your first question is – and should be – why? In a nutshell, reducing an object’s temperature to -300ºF re-arranges its molecular structure, creating greater uniformity that results in longer life and better performance than when the product was initially designed.With vacuum tubes, this process has a profound impact on a tube’s ability to endure thermal shock. Therefore, tubes can last longer and their sound can been enhanced in ways that are simply exquisite.
After thoughtful and thorough research, Upscale Audio chose 300 Below because of their extensive experience in working with musical instruments as well as auto racing, metal tooling, and high-end sporting goods from rifle barrels to golf clubs. Expect nothing but the best from Upscale Audio.
Our charge for Cryogenically treating tubes is a fraction of what others charge, though we use the premier company. Count on Upscale to do the best job and not price gouge . Also available is cryogenic treatment for cables, along with our well-known Nordost Vidar cable treatment system. Call for details. Pricing is listed on each tube and cable page.
Vacuum tubes are warranted for 90 days against defects, except in cases of abuse, and replaced with like-item only.
Exceptions to our warranty policy are as follows:
Upscale Audio is not liable for any damage or injury caused by the improper use of its tubes or the use of an incorrect/incompatible tube type. If you are unsure of what tube or tubes your equipment uses, consult the manufacturer before making a purchase. Using an incompatible tube type may cause severe damage to your equipment and will void your tube's warranty.
Vacuum tubes are electronic parts and are not refundable under any circumstances.