Hi all. Someone recently suggested that I lose all the fine tuners on my fiddle except for the E string. He claimed this would improve the overall timbre of the instrument. Any truth in this claim? The fiddle is pretty ‘bright’ as it is. I don’t really wan’t to add to the overall brightness of the sound. But, if it worked in the other direction, darkening the sound well… that would be just grand!
Arbo
I did that on my fiddle, Arbo, for the same reason - to tone down a bright instrument.
In theory, I’d think that losing the tuners would improve the tone by 1) substituting string-to-wood (tailpiece) contact for string-to-metal, and 2) lengthening the strings behind the bridge, lowering the resonances.
But I’d say in my case that it made little difference, other than making it more difficult to tune. 
As a compromise, one of these days I plan to try replacing the tailpiece with one with integrated fine tuners. Ultimately, I suspect that other setup parameters will make more difference - soundpost, bridge, and “darker” strings.
I changed my ebony tailpiece with fine tuners to a Witner integrated one - very light weight. Didn’t seem to change the tone, but I think it did increase volume a little.
My fiddle is now a little brighter than I like. I took it in for a set-up last year. It plays very comfortably indeed now, but somehow the process took some of the warmth out of the tone. 
I took it back and the shop guy tweaked and tweaked, but still couldn’t restore the original tone. It’s ok, and it’s only a cheap fiddle, but I used to really like the tone and now it’s just kind of… ok.
Bummer.