After several tries using DelayFB, mono and stereo... I realized that they have a bug.
When a sound enters in the abstract, it cames out at the same volume (direct). Then, it starts the delay-feedback... it should start with feedback applied... but it doesn't do that. The first delay is at the same volume as the direct.
The fix is by changing only a connection inside [pd working]:
This:
[inlet~ signal]
|\
| \ [*~] .... (receives from vd~ and $0-feedback)
| \ /
| [delwrite~ $0-fbbb 1000]
|
...
To this:
[inlet~ signal]
|\
| \
| [*~] .... (receives from vd~ and $0-feedback)
| |
| [delwrite~ $0-fbbb 1000]
|
...
So, the first feedback has the volume decrease.
Attached mono and stereo version.
If I'm mistaken, PLEASE, LET ME KNOW!