I’m working with this setup that records a loop, plays it back, adds stuff on top, re-records that, plays it back, etc. to build up material. It is really tricky to get the gain just right in a setup like this… if it’s a little too low, everything fades away. A little too high… everything blows up. Even on a digital device like the Octatrack, keeping a steady level is total trial and error with the gain settings. If/when I play a live set with this setup, I think the sound person at the venue is going to hate me.
@chorist Compression may be what you want for this. Even if it's not the same exact thing, you may want to look at the old reggae guys and how they set up their dub loops for inspiration.