This 6922 tube type was rated the "best buy" by Vacuum Tube Valley magazine in their 6DJ8 / 6922 tube shootout. They cited a better bottom end and "less offensive" high frequencies as two of the reasons for their choice. This is also the same tube which is sold by Richardson's under the Bugle Boy brand name.
New Old Stock * No longer available for Export MFR: Sylvania SKU: 6922-SYL
7308 is a high quality tube in the 6DJ8/ECC88 family. These Amperex have steel pins. They are designed with low microphonics and low noise. Similar to 1E88CC
New Old Stock * New In Box Limited 90 Day Warranty MFR: Amperex (Holland) SKU: 7308-HQ-AMP
7308 is generally the highest quality tube in the 6DJ8/ECC88 family. These Amperex tubes have Gold pins. They are designed with low microphonics and low noise. Similar to E188CC.
New Old Stock * New In Box Limited 90 Day Warranty MFR: Amperex (Holland) SKU: 7308-GP-AMP
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).
New Old Stock * No longer available for export MFR: Made in Russia