#1
I own a Boss DD-6 delay and I'm having some issues with it.

When I use it with a clean/lightly overdriven sound, the delay acts like I want it to - the initial repeat is about 3/4 softer in volume, and it decays nicely. When I crank the distortion up, though, the delay gets really harsh - the repeats are pretty much at the same volume as the initial note, and it doesn't decay well.

I used to think this was an issue with my amp, since I had a SS amp for a while - I just upgraded to a Crate V16, though, and I'm having the same problem. My chorus pedal seems to suffer from the same thing.

Do I need to get an external FX loop to make it sound right?
#2
From what I've heard, time based effects like delay and reverb should be applied after distortion, so unless you use a pedal, I think you should probably have an FX loop. I don't have any first-hand experience with pedals, though.