I’ve been down that route, had the KP3 twice. Transitioning is not that easy… fading up the loop while turning down the gain knob (or changing the input to mic, as a way to mute the RCA inputs) is less than ideal, imho.
You could always have a dj mixer in between, but then again if you want to process the loop with the KP3 effects, you would have to remember to change the input to mic or turn down the gain to avoid a doubling effect, since touching the XY pad let’s the input sound come in (assuming you would use it in send mode, which makes the most sense). Although its sampling is as straight-forward as possible, that caveat made me sell it for the second time (plus: it degrades the sound quite a bit, effects are more quantity than quality, and I still needed a mixer in between, which brings me this other comment of yours:
That beeing said, I already had the OT, but was looking for a way to minimize / simplify my setup (ie. easier, no-brainer looping)… I eventually came back to the OT, precisely for the reason you’re mentioning: there’s no other hardware looper - NONE - which has some kind of crossfading between both sources… which is a reason I’ve cried to multiple developers - of both hardware and software - hoping they would create something similar. (ie. a standalone iOS app that mimics some of the features of the Xone DB4 - looping, good quality fx, matrix routing - without the need of buying a 2k, gigantic mixer).
So far, no luck… and ALSO, I’ve gone the iPad route as well… made multiple setups, specially since my setup is mostly Digitakt and it’s now class-compliant… so very tempting.
There’s issues there as well: first of all, and the most obvious -stability. I can’t shake the feeling that it might crash mid set (it has indeed happened at least once live - I think due to an electrical problem - and I’ve had many apps crashing on me over the years). You could get a pretty nice setup with a few apps, but the main problem (for me) is that is not as easy to get a crossfader curve where you get 100% signal of both channels in the middle, which is kind of the idea if you want to mix tracks, imho. but if you want to mix with individual channel volumes… it’s much easier. I managed to do this crossfading thing btw, but it involved creating custom MIDI mappings with specific curves to be able to make it behave that way…
OK so… back to the Octatrack.
My current setup is simply OT and DT. I had a Faderfox UC4 to have quick access to some parameters, but I think I might leave it out, and face those limitations as a way to simplify my music even further - a never ending quest I’m on.
I’ve come to get accustomed to transitioning with the OT, BUT… it did take many, many moments of frustration until I got it right. And even now, that I’ve been using it for years… the unexpected might happen. So there’s still things to consider, but I have to agree that I’m going deeper and deeper into this method, trying to make it more sophisticated, and my transitions are getting more interesting - sometimes almost turning into tracks themselves, which is something I quite enjoy.
I can explain my setup further, but this post is long enough already! shit, this always happens when I discuss this stuff… hehe
Anyway, hope this helps. As an alternative, There’s now finally (relatively) cheap, small pedals with MIDI DIN in, which is something that took a LONG time. EHX has it’s 1440, now Boss joined with it’s RC-5 (IIRC that’s the model) so if you want something more straight forward and less prone to failure or accident (bad kind of accident) then you could consider a DJ mixer and one of those (I think I like EHX’s more, looks more hands on… yes, it’s not a single device, but it’s what we have, unless until Elektron comes up with a mixer/looper kind of thing (which I don’t think will happen soon since the OT sort of is that + much more)… or maybe someone else takes advantage of that hardware gap.