I use MonkeyC Audio Rewind on the computer, and from my phone either Koala, Life field recorder, or just the Voice default recorder app, which I also have as a complication on my Apple Watch to quickly catch sounds while out and about that would get missed in the time it takes to get the phone out.
Roland P-6 is fast but sample time is tight if you’re looking for any kind of fidelity. Rechargeable battery, small enough for your pocket (almost) and samples are instantly saved when you turn off the machine.
Otherwise Koala if you’ve a phone or iPad always handy.
Also check out Ocenaudio, it’s free and great to just keep running in the background recording all tracks of your audio interface, including all loopback tracks. You can pause and resume at will, cut and drag directly on disk or into another software. You can also process with plugins inside of it. Pretty cool for free software.
I have Rolling Sampler but I find it’s a fiddle to grab and edit the sample out from the stream. I prefer something that can record when I tell it to, and independently of the DAW’s transport if needed.
Given your use case: Another vote for Roland P6 here. I like the way the samples sound through the onboard mic, and you can loop them.
Like @neilbaldwin said, there are some short limits on sample time: 5.9 seconds mono per sample at 44K, 11.8 at 22K, etc. But I don’t find vocal “aah” loops or pot lid klangs need much sample time; the memory is fine for intentional sound capture. Obviously it wouldn’t work for long, high fidelity “leave it on RECORD and see what happens” recording.
With the paid upgrades you can bash out half decent tunes in an incredibly short time. It’s really well designed. You’ll learn 90% of it in an arvo too.
Hardware: SP404sx.
Much more fast to learn & use than the 404mk2. It’s better for speed because there’s no bloat: just pads, FX, a built in mic & that basic AF sequencer. Like Koala, you’ll have it mastered in an arvo.
Pick either of those then learn the art of resampling & microwave beats on it & you’ll get whole albums done in a weekend.
it’s sampler is a sampler and a full fledged beyond all grain synthesizer…
every audiofile can be sliced in various ways and can end up in a new sampler device or the drummachine rack, which is nothing but a container with pad slots, where each single one of those, can provide an individual sampler or synth or vst device…
and with it’s latest addition of a master recorder (totally indepandant from the transport), u’ll can always hop on and off in resampling and resourcing grandezza, from anything ur about to do at any given moment…