Okay this is just great.
A thread like this could raise the prices of these things.
In my testing in the Monique Rack:
To my ears the black plate RCAs were the sweetest.
The Sylvanias had a rough lower mids with otherwise clear sweetness.
The GEs were as good as the Shugaungs. Just not as musically exciting as the others.
I have some Shugaungs that were made more than a year ago that are reliable noise free (little gurgle on start up) and I won't replace until they go bad. They are musically interesting.
The JAN Phillips is very very sweet.
Definition of sweet: open, airy, full hifi frequency response. No mud. No grit except what you make with your attack. A very pleasant richly harmonic sound. Allows all the strings overtones to be expressed.
Some tubes that weren't labeled JAN are the same build. The armed forces determined that the consumer tubes met their specs.
Tube testing won't necessarily reveal microphonics. Pete Cage has this device that can detect some.
An EM pulse from a Nuke and that hard banked turn in your B-52 to avoid the cloud and shock wave won't reveal the tube's microphonic tendencies.
The tap I can deal with. The howl like "Dog Symphony #4 by Hounds Boneman" sounds like you have a looper.
In my case a very microphonic tube works great in V2 where the gain is much much lower.
