Quietest 6922 type tube?

E88CC and 6922 are the same thing. ECC88 is the 6dj8 and E188CC is the 7308.

Of those you mention, all can be very quiet. Differing testing parameters and the vintage of particular tubes render your question almost impossible to answer. If early-60's Siemens and given good microphonics, they will be very quiet. I think the best all-rounder of those you mention in terms of a nice house sound with good extension on both ends is the PQ USA White Labels. Of course, tubes are component dependent. It is always a crap shoot, which is why tube rolling is both popular and expensive.

Stick with a reputable tube dealer, when possible. If buying from a private seller and they are listed as "matched" or "tested", ask for the results and get it in writing that you can return them for a full refund if they prove less than what is advertised. Good, honest tube sellers should not have a problem in this regard.

Oh, and check with the manufacturer of your component whether the 6N1P can be used in place the tubes you mention (not ALWAYS the case). Some find they sound MUCH better in some components for a lot less money. So much less that if you can use them you won't be out much for the trying.

Perhaps others will have differing opinions, but I do not think most Golden Dragons available can hold a candle to ANY of the tubes Dogpile mentions. Actually, and unless I am greatly mistaken, Golden Dragon does not make tubes but rather, sorts, tests, matches, and re-labels tubes made by other manufacturers and exacts a hefty fee for doing such. I would admit to being humbled if proven wrong, but this has always been my understanding.

FWIW, I contacted a person that I know who used to work for VAC (they used these tubes almost exclusively as stock in their products). This was his answer to my inquiry,

"The Chinese tubes that were labelled Golden Dragon were indeed the "pick of the litter" from the bulk tubes made by Beijing Radio. However, the factory converted to producing light bulbs exclusively about 4-5 years ago, so no more Chinese 9 pin miniature tubes. Assuming that Golden Dragon 6DJ8s continue to be sold, they may be leftover stock or they may be labelled Eastern European or Russian tubes."