For what it counts, we have slighty different labeled tubes referring to printed numbers (mine has 322 EAD + 7002).
Don`t remember exactly from what year my tube is but maybe thats where difference comes? Different year & batch?
O_o That`s really weird that you can`t notice any improvement and find it even worse! ;S Green label JAN Sylvania 6922 should definitely be improvement over 6922EH ! First difference you should notice is better & more "foward" mids section + tighter bass. Soundstage is more or less same. Is this your first NOS tube? If you haven`t done analytical comparing before then maybe your ears aren`t used to finding differences. Also, what headphones are you using?
Btw, there are different label Sylvania`s, are you sure you got Green label JAN Sylvania 6922? Maybe yours is later production (worse sounding?) or it has reached to it`s "end of life"?
My tube is labeled like this: http://www.ebay.co.uk/itm/6922-Sylvania-Electronic-Tubes-/251024184077?pt=LH_DefaultDomain_0&hash=item3a7235130d
Except my tube has different number: 322 and next to it is EAD and there is also vertical number 7002 near the right side of labeling.
I'm using hd650s and this is my first time comparing tubes. I definitely am not used to comparing differences, but thought I would at least notice a few differences and definitely thought I would prefer the new tube, but I find myself wanting to put the old tube back in. I will use it for a week and see if the sound improves.
Well, then I don`t know what to say. With my setup the difference is definitely noticeable from the first moment I plug in my JAN - certainly better than 6922EH in every aspect imho. Well, maybe only thing that is better on 6922EH with only atmospheric electronic music is the bass which has more flow & sustain but in other genres JAN is certain winner.
Maybe HD-650 is too warm headphone for this tube?
LACKS DETAIL: The HD600 has a very smooth sound that can sometimes feel slow and slightly blurred. The HD600 is not the last word in terms of detail retrieval.
TOO SMOOTH: The HD650 can sometimes sound suffocated in its own warmth. It can sometimes sound as though it is attempting to lull you to sleep.
6922EH sounds more brighter and gives "more air & life" and thus feels better for you? Anyway, sorry that my recommendation didn`t work out for you ;(
Edited by CoiL - 12/24/13 at 12:43am