AUDIO GEEK ALERT!!! 6267 Preamp Tube Shootout for Neumann U67

Thanks to Michael Keating for playing the acoustic guitar for these preamp tube tests. The mic originally had a Mullard (who knew?). I always had a General Electric version in deference to my father’s 45 years with them, I recently purchased a Hammond (by Mullard) and an Amperex.

Guild D55 with the Neumann U67 roughy a foot out, positioned just to the neck side of the sound hole.
B&K tube tester worked flawlessly. All tubes tested good, no shorts. Mullard 76, DE 78, Hammond 81, Amperex 78 FWIW
Individual RTA’s confirmed what our ears told us.
Excel spreadsheet with comments over RTA’s

Nothing is easy, but the Amperex is staying in the microphone … for now, with the GE a close second.