Amperex 6922 USA vs Amperex 6922 Holland

I have compaired them both. The USA and Dutch versions are similar except the US 6922 version has a bit more resolution and HF extension where the Dutch 6922 has more body and fullness with slightly less resolution than the USA version. Both are excellent so it comes down to personal perefence as to which ones you perfer. I like both alot. The Amperex 6922 are more lively than the Amperex 7308 PQ although the 7308's have greater extension on the bottom end. Johnny

Roc:

Were the tubes supplied by AR?

If your USA BB's are Richardson Electronics tubes (Richardson purchased the Amperex namesake quite some time ago and therefore can rebrand any tube "Amperex") they could be most anything.

I have yet to see a vintage Amperex "USA" 6dj8/6922 with the BB logo (all have been of Euro manufacture).

Maybe ask AR (if applicable) who manufactured the tubes in question as they should know what it is they are buying/supplying.

Obtaining a positive ID on your current tubes should allow for knowledgable comparisons as Richardson does not always rebrand the same tubes (same manufacture) from what I have seen.

If "USA" does designate that the tubes were manufactured in the US, then they are most likely Philips ECG's or Sylvanias.

Neither have an overall great reputation for sound quality, but having tried some specialy tested/selected Sylvania Green labels I do know that they can sound quite good in this case (meaning pretty damned good when compared to some of the Holy Grail 6922 types).

It would be useful to note that 6922 is not exactly similar to 6DJ8 or 7308 though they sprouted from the same family tree over a period in history. Unless a tube is specifically labelled such, even suggested European interchangeability I guess are based on industrial instruments or radio applications.

Be aware which tube designation number is originally specified for the particular audio circuit before we start rolling within the same tube id. Hopping across numbers even within the same tube family is often a "dicey", expensive and endlesly frustrating activity. I have several 6DJ8's I cannot use to testify that it is so. My MF tube buffer calls for 6922, nothing else.

So making good judgement which tube sounds better for this thread should rightly refer to 6922 brands & versions.
A useful data site http://tdsl.duncanamps.com/show.php?des=6922