The Ultimate 12AX7 -
- it's big, warm, and musical with High Gain, ultra-low microphonics, and superb linearity with a dynamic 3-D sound. The Tung-Sol name and trademark have been acquired by the New Sensor Corporation. This production Tung-Sol tube is manufactured at their Xpo-Pul factory (also known as Reflektor) in Saratov, Russia. New Sensor is an American corporation and since taking ownership of this factory has been steadily improving the quality of current production tubes.