I had an amplifier that came in with extremely microphonic EL84 tubes - they were literally feeding back if I bumped the amp.
I put these tubes into the etracer and they passed the quick/full test and one of them only failed the corner test once and passed after that. I assumed with the tubes being so bad that this would be an easy catch. I am still very very new to the tracer, but is there a test that can catch a tube with bad microphonics?