mr dave

are you using an actual electric violin or an acoustic with a pickup?

right off the bat you're going to blow the tweeter in that guitar amp if you haven't already (which is EXACTLY the sound you describe with the nasty scratching sound - the center of your speaker is probably shredded).

i don't know of any specific violin amplifiers out there either. most acoustic amps are still made for guitars (and the range of frequencies they produce) a violin wouldn't do much besides destroy the high end.

what most people seem to do is run the violin through an acoustic preamp (like Fishman or LR Baggs) then into a PA system. by having that middleman device in the chain you can then start tweaking your frequencies before they get to the actual device that amplifies them, you'd also want to run your effect between the pre-amp and the PA.

what kind of distortion are you planning on running it through? a typical electric guitar distortion pedal will fuzz out your sound but it won't sound that good as they're still only made to handle certain frequencies. a proper rack mount effect unit rather than a stomp box should be able to handle the wider range of frequencies, it'll cost more but sound better.

__________________
i am the universe