Fade out on key off

Petar posted Nov 20 '16, 19:24:


On key off events (with samplerbox_20160831.img installed) there is a short fade out, about half of a second.

Is this normal behaviour ? Is it possible to turn off that feature or to modify the duration of the fade out ?


(By the way, are samples loaded into RAM or is samplerbox reading them directly from disk ?)

Petar posted Nov 30 '16, 20:03:

I've made some tests but could not find what is wrong.

I've mapped a sample consisting of an upward D scale recorded twice.

The sample starts normally when key is on but when i release the key it continues to play, you can hear 3 or 4 notes fading out.

I've tested this with the built-in sound card and the Lexicon alpha.

Here are the audio files of the results, recorded from the speakers :


Anyone has a clue on why is this happening ?



HansEhv posted Nov 30 '16, 22:38:

Hi Petar,
Samplerbox has a builtin fadeout length of 0.3 seconds.
Look for the statement "FADEOUTLENGTH = 30000" and adapt to your need. This may turn out to be too static however..
I made an alternative/extended SB implementation with several extra features, amongst which a configurable release time per sample set.
You can adapt the technique yourself or use my build if you like it.
It can found here: http://homspace.xs4all.nl/homspace/samplerbox

Petar posted Dec 1 '16, 09:16:

Thank you Hans !

I would like to set the length to 50 milliseconds.

I'm new to samplerbox and don't know where to find the statement you mentionned and how to change it.

Is there any documentation available for that purpose ?

Petar posted Dec 2 '16, 22:44:

Hi Hans,
Sorry to insist. I'm preparing a live performance for February and I'm planning to use SamplerBox.
Do you have any hints on my previous post ?

HansEhv posted Dec 2 '16, 23:49:

Hi Petar,
No documentation on this as far as I know...
The statement is in /root/samplerBox/samplerbox.py.
When you connect you are already in /root, so it is one directory down: cd SamplerBox
Edit the script (for instance with nano as this is more friendly than vi): nano samplerbox.py
In nano, the find instruction is ^W (control-W), saving is with ^O (control-O).
Just change the 30000 to 500 and save.
Mind that you will have to do a real poweroff or reboot later (just unplugging the power might corrupt your filesystem).
But for now you can test with:
systemctl stop samplerbox
This will start the script in your terminal.
If you made an error, it will show up there.
Stopping the script is with ^C (control-C)
It also speeds up the process of adapting the value, should 50 milliseconds not work out right.
When all is fine, you can either reboot or issue: systemctl start samplerbox
Hope this helps (and that I didn't make any typos - this without having acces to the pi now.)

Petar posted Dec 3 '16, 09:54:

Many thanks Hans !
So all this is done by command line ?
What is the command for rebooting ?

HansEhv posted Dec 3 '16, 15:08:

Commanding is all you have (plus texteditor nano).
Reboot is reboot, power off is poweroff.
Seems obvious but I know it isn't in Linux world :-)
However if you're that unfamiliar to Linux, make sure you have the SD image backed up in case things get out of hand.
Anyway good luck!

HansEhv posted Dec 3 '16, 15:10:

Sorry, meant commandline of course, my phone corrected me the wrong way :-(

Petar posted Dec 3 '16, 18:57:

Followed you're instructions.
It works !
Thank you Hans.


  (not published)
  I want to post as guest