Loopers seem like inspiring practice tools. But they don't work with distortion. If the looped piece is going to the distorting amp, along with the new piece I'm playing it'll turn into one blended, distorted mess.
So how does one do this? Far as I can figure, it needs to be a looper with a built-in amp simulator, into a clean amp. So the distortion comes from the looper, not the amp it goes into. And it would need two parallel (internal) amp "channels"- one for the loop and one for the fresh input.
I'm looking for one piece of equipment that's portable, i.e. the size of a pedal. Operation on batteries an added plus.
What I have now is a Korg Pandora PX4D which I love.
http://www.musiciansfriend.com/amplifiers-effects/korg-pandora-px4d-guitar-multi-effects-processor
Small, long battery life, amp simulations are good enough for practice. I run it into iPod speakers for practice away from home. Works great.
The Pandora has a delay effect which achieves almost what I want, except (1) delay time is too short topping out at about 2 seconds and (2) delay needs to loop infinitely.
Oh yes and (3) it uses horrible low definition compression for the delay playback, something like 96bit mp3 - just terrible! (The only thing I don't like about it.)
Does such a thing exist? Maybe any garden variety Zoom multi effect can do this? I don't know.