The JJ 5751 is an excellent 5751 vacuum tube and does exactly what you want from a tube with this designation. It has a very low noise floor and no tendency toward microphonics. It is a very quiet, low noise alternative to the 12AX7 amplifier tube with slightly reduced gain. The trade off, is that to my ears it has less harmonic content and detail compared to the GE 5751 or a good 12AX7. The physical construction is similar to many 9 pin miniatures from JJ, with small plates and great build quality.