Dub looper to manual grains questions

Hey there!

after watching Neil’s video 20 to 24 or 25
I missed the “How to” stream sound from (any source, inputs, outputs…) let’s say from a dub looper to a manual grain?
It has some related to buffer sharing but I’m lost here, I don’t get the idea of buffer to start with… If some kind soul could link or explain slowly those things, that would be awesome!

That kind soul was Joe’s, in an other thread: Unofficial Getting Started Videos
"A buffer is just an area that’s set aside in memory to hold some data. In the case of the ER-301 when we talk about a buffer, the memory is RAM memory, and the data is an audio or CV recording.
Units that use buffers - the sample player and recorders - can each use their own unique buffer. Or they can share a buffer with another unit, in which case they share the same audio or CV data."

NOW
On track 2, I got a source, the radio music thing, and some fx. Output 2 in my rme.
On track 3/4, I got a dub looper with a 2 bar reset, engage on,
punch on, internally listening output 2.
Next to it,
a manual grain share the same buffer (select pool => select the current buffer => enter)
and then Neil’s video are super clear… And it sound terrific!!! ha ha!..

BUT
Physical output has more gain than internal routing, why is that, what’s under the hood here? What am I doing wrong? Both rme’s preamp are set equally of course…

Thanks for your educational inputs!!

hmmm if i’m understanding you correctly it could be the gain level in your manual grains? i would check there first…

Ho dam’… I made a mistake in my patch… There’s no pb of gain at all…
Stupid me, I was driving the grain out thru a mixer and totally forgot about it.
thanks claasp for the heads up, somehow it helped me refocus!
Cheers!