[Boatanchors] 6146 A or B ?

[Drew P.]

Carl and Glen:

Thank you for your insights on the "FADF2" and instability problems caused by its indiscriminate use.

Carl mentioned near-uniformity of most 6146 and 6146a, but large differences in 6146B.  The 6146/6146A was a product of the early 50's, while the 6146B was a dozen or so years newer, as per some other writings by Glen.  

My conjecture: Perhaps the differences in 6146B accrue to the end of the tube era rapidly approaching at that time, and the manufacturers setting their sights on the next wave, thereby giving tubes only modest attention, knowing that in a few short years it wouldn't matter anyway.

Drew