Mullard CV4004 / 12AX7 / Russia
The new Mullard CV4004 / 12AX7 vacuum tube has a short plate construction making it more stable and better able to handle the vibration inside guitar combo amps.
The CV4004/12AX7 is a high gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in high gain Marshall pre-amplifier circuits where noise and microphonics can be a problem. Best for guitar amps."
The Mullard name and trademark have been acquired by the New Sensor Corporation. This new production Mullard CV4004 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.