JJ Electronic ECC83S (12AX7) Vacuum Tube Purchased as a spare for a guitar amplifier and used only once to confirm its operation. I am selling it because I no longer need it as I have gotten rid of the amplifier. This is a tested product purchased from a reliable shop. I will carefully package and ship it. If you have a compatible model, please consider it. Type... Guitar Amplifier Vacuum Tube JJ Electronic ECC83 12AX7