You mean to say that the results of your vocal tracks recorded with a U47 modified to accept a EF14 are close in sound to a U47 with a VF14?
If so, how did you determine that in an objective way that could be shared?
I am not able to determine that from your sound files. They do not indicate which mic and which tube is used on what track, nor do they detail the processing of the vocals (EQ, compressions, etc), nor the resolution of the sound file. It would take a high res file produced in a controlled, supervised environment, with a mic where the only thing changed was the tube, and a signal chain void of any processing, and two performances that are identical, with a singer exactly at the same distance and angle for both recordings, and with the exact same volume on each passage.... I hope you get my drift.
If you are happy with the results, that is really all that counts. Even the more so if others share your sentiment that teh voice translates well. But if your post was meant to make universal statements about substitute tubes, let's stop the discussion right here, because the methodology you chose is highly unlikely to prove or disprove that.
