New, unused US GE JAN5751 / 12AX7 vacuum tube, with original box. The 5751 is similar in construction to the common 12AX7 vacuum tube, but with some differences in electrical parameters. The 5751 has lower gain compared to the 12AX7, making it a popular choice for audio enthusiasts who want to reduce the amount of amplification in their circuits. Although some adjustments are needed due to the lower gain, it can be used as a direct substitute for the 12AX7 in most applications. The 5751 is often used in instrument amplifiers and hi-fi audio systems, valued for its smooth and warm sound quality. It is used in various audio equipment such as guitar amplifiers, preamplifiers, and phono stages. This is a new, unused JAN 5751 vacuum tube. It is equivalent to the United States Military Standard (US Military MIL standard), also known as MIL-STD or Defense Standard. The JAN 5751 on offer is new, unused, and comes with its original box. Recently, the production of these JAN vacuum tubes has been discontinued, and prices have risen considerably. Please refer to the photos for your assessment.