#1
I have a Vox AD30VT Valvetronix and i use a Fender MIM standard Strat. Anyway, i started to notice that when i have gain on all the frets from like 7th fret and lower (7,6,5..) sound louder than the frets that are higher...Something like i was playing Mr. Crowley and i could do the begining and all but when i get to the solos it sounds quieter and thinner which makes it sound like crap.

I recently changed from D'addario 10s to Ernie Ball super slinky 9s and i noticed a huge difference in tone (not for the better) but it was much easier to play. I changed to see because everyone was saying how good Ernie Ball is, and well they just dont suit my style, but i like how it is easier to play, which i could probably get from 9s on D'addarios. Could this have something to do with it?

Could it have something to do with my pickups? I have stock pickups and it happens on the bridge pickup. The middle pickup has a bit less and the neck pickup is the same as the middle. Could it also be my bridge? cause i noticed a while ago that my bridge seems to be a bit broken, as the hole where i put my whammy bar is all dent inside, so it wont fit well unless i smash it in...

Oh and the tube on my Vox is slanted and i also wonder if this has an affect on my sound.

Sorry for all the text, just really wanted to find out whats wrong. If i missed anything sorry.
My Gear:
Fender MIM Standard Stratocaster
Squire Stratocaster
Vox AD30VT
Boss DS-1
Boss Super Chorus
Ibanez Weeping Demon Wah Pedal
#2
I'd probably take it to your local music shop and have them check it out.

2004 MIM Strat w/ Fender Hot Noiseless pickups
Sovtek MiG 60
Avatar 2x12 w/ Celestion Greenbacks
Snark Tuner
MXR Custom Comp
Fulltone Full-Drive 2
Dunlop JHM3 Univibe
TC electronic Nova Delay
TC electronic Arena Reverb
#3
(out of topic) I'm Peruvian too, so your not the only one, lol.

(on topic) I guess i would have to do that, but i want ot know if i can do anything myself before i make a trip to the music store.
My Gear:
Fender MIM Standard Stratocaster
Squire Stratocaster
Vox AD30VT
Boss DS-1
Boss Super Chorus
Ibanez Weeping Demon Wah Pedal