I've got a 5-8k "curiousity" in my vocal. It's not picked up so quickly if listening to me in open air ... but those with sensitive ears get how it gets picked up electronically. It's there -- and gets accented by most mics that accentuate said upper freq range ... because normally, that range represents "presence" in a vocal, and accordingly, mics are designed accordingly. The problem is that's a problem for me because my timbre naturally accentuates that range. I need taming in that region.
Tube mics have a natural smoothing of upper frequency harmonics ... so Jim over at RP advised me to get a Karma 58 tube mic and swap it out w/ the GE 5 Star tube.
I got it in, and was unimpressed ... because I'm a cheap fucking Yankee and can't follow directions exactly against my cheap. At that time, I was also running tube into Peavy VMP-2 (also Jim's suggestion), a tube pre -- and it really didn't sound right. It sounded nasty.
I knew I needed to find a different pre -- tube into tube = suck ... and I fell into a Trident Celebration at Git Ctr in Manchester (you know where that is

). It was a 1200 or so piece I got at clearance for a couple hundred bucks. Right place at right time.
But as good as the combination has been, I've also discovered other tools that help ... and even if I told the tell all story, it wouldn't work for most ... because it's my story, not theirs. It's not like shoes. Size 8 doesn't fit all size 8s.