Ill just clarify this effect before bedtime.
On the repeater you have 2 rotaries... in Trim Mode, one trims the start of the loop the other trims the end of the loop.
Unfortunately you canīt dial them together, but you should be able to. (with practice you can alternate your twists pretty fast)
So if I trim the end all the way to the beginning, (So i am hearing a loop that is just the first second of the first loop i played) I can THEN madly dial both encoders, and track thru the whole recording from start to finish, by hand. Now I would LIKE to be able to do this with ONE knob.
There is a completely far-out but low fi looping synth module that I USE now for this effect (you need a modular synthm and powersupply, and a whole fistfull of cable to get it to work) (Called the Tyme Sefari http://www.theharvestman.org/1973.php
) that has these trim knobs (in and out points if you prefer) that even allows that the trim points cross each other so that the in becomes the out... etc.
This whole thing is, in effect, the good ole loop windowing, but with the added bonus of NOT losing the loop after a hefty stomping session on the UNDO pedal.
People ALWAYS ask me after a gig why Im stamping on one swich so much... ha ha