Large sound stage with excellent detail. Factory selected for low noise and microphonics. The Mullard name and trademark have been acquired by the New Sensor Corporation. This new production Mullard 12AX7 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.