[6BQ5]

This seems to be an interesting new device for testing tubes. It can store profiles of individual tubes in a database in a computer.
It also can test tubes at their spec'd voltage limits, which provides a better picture of real-life performance.

I'm curious whether this is what RAM labs uses?

http://www.amplitrex.com/at1000.html

[Roger A. Modjeski]

Appears to be more specific to audio needs. I did not see any mention of the repeatability of test data or component drift. Keep in mind that it takes over 100 tubes tested in a batch to make good quads and pairs. Even then there will be several "lonesome soldiers" who have no match.

Be advised that several "tube matchers" bin the tubes with ranges we know not and then print labels with identical bias and transconductance numbers. Be advised, no two tubes exactly match and a preponderance of identical labels should tip one off. It certainly got my attention.