Simple easy fix to a common guitar looper problem
The cost for this fix is exactly $0.00.
A problem with all loopers for guitar players be it a Ditto, DigiTech JamMan, BOSS RC-3 or otherwise is that when you record a loop, play it back and then attempt to play a lead over it, it's too loud.
There are two ways to fix this. One does not work and one does.
Easy way that does not work
If your looper has a volume control, you record your loop, then turn down the volume control. But then you end up with something that doesn't sound natural, so this solution really isn't a solution.
Easy way that DOES work
Turn down the tone control on your guitar.
Seriously, that is all you need to do.
Where this method does not work is for metal music since distorted guitar has a "flat" volume where using the tone knob makes little difference in overall volume to the ear...
...but then again, looping with metal riffs doesn't work anyway because that specific guitar sound was never suited for it. Everything else is, but metal is not.
The only way you can loop with metal (sort of?) is by stereo separating the channel. As in rhythm riff on the left, lead riff on the right. Most looper pedals don't do that. Yes, the stereo looper exists, but it's more trouble than its worth because you would probably have an easier time simply multitracking your riffs in software and panning instead.