I am finally learning how to shift into third position and beyond. I have trouble hearing if the notes are right the higher I go. I watch Fiddlerman play in higher positions and the violins he plays seems to never loose (for lack of a better word) the power behind it. There's been times that if I wasn't watching him I would have never known he was playing that high. My violin sounds good the first note or two into third and then to me it starts loosing it's sound, thus the reason I think I'm having trouble hearing if it's right or not. I was wondering how much of this could be me not knowing what I'm doing and how much could be I need to upgrade to a better instrument.
My violin used to give up after sixth position on the lower string, but I fixed it by playing long bow strokes at those given notes. Kind of like breaking the fiddle in but it's vibrato. Like you said it is man versus violin so vibrato your heart out and force that violin to sing. However, if you hurt yourself - the violin wins , and you need a new fiddle.
I think every note on the violin amplifies, echo's, and resonates off of unique locations inside the body of the violin, and do to create the best sound you have to perform upon each of those locations so that the violin itself shapes to those sounds. The string vibrations and sound is like a drill upon the back of the violin, and to create a bigger sound you need a larger drill - thus vibrato lengthens the sound waves as it resonates on and inside the violin.
so when you have a wolf note, it may be a location on the violin where there is to much wood preventing the sound from reverberating. In extreme cases the violin would need to be disassembled and have wood removed, but in smaller cases, a lot of diligent vibrato can shape the wood to a lovely sound.
There are some possible answers....in the concept that Jacques started, you need to explore ways to make your instrument respond to whatever you need...
However, there is a chance that
a) You violin needs to open up in those high positions, that will take a few months maybe of regular playing in the third position. Scales with dynamics in the third position would help.
b) You need a different string, (maybe a different string gauge) to drive your violin properly in the upper positions (dead and old stings make this worse of course)
c) nothing of the above improves the situation and you need an upgrade. Actually I strongly believe that one should play with the best instrument he can find and afford (not the most expensive of course, just the proper one). If something in your violin discourages and discomforts you for a long time, and trips to the luthier don't pay back, its upgrade time