6DJ8 / 6922 / 7308 / ECC88
- 6DJ8 / ECC88 is the "standard grade" of this family. They normally have steel pins.
- 6922 / E88CC is a "premium grade" version of the 6DJ8. Most have gold plated pins, but many Sylvania manufactured 6922's have steel pins (a few Sylvania's are gold pin).
- 7308 / E188CC is generally the highest quality tube in the 6DJ8/ECC88 family. Most have gold pins. Sylvania's are steel pin. They are designed with low microphonics and low noise. Sections are usually pretty closely matched.
