Open Ableton Live.
Locate the audio file on the computer's hard drive. Click-and-drag the audio file to the track labeled "Audio 1."
Double-click the audio file in "Audio 1" to display the waveform in the editing window.
Press "Play" on the transport bar and watch the waveform. When the play head reaches the portion of the audio file to sample, press "Pause."
Right-click on the first peak of the sample and select "Set 1.1.1 here." Right-click again and select "Warp from here" to lock the sample to the tempo grid.
Drag the loop bar to select the entire portion of audio to sample and click the "Loop" button. The audio will now loop in tempo at any BPM.
Connect the audio source to the Boss SP-303 via the line-in jack.
Press the "REC" button on the SP-303.
Select Bank "B" and press pad 3.
Press the "Stereo" button to enable stereo sampling.
Begin playing the audio from the connected source. Press the "Rec" button when the audio reaches the portion to be sampled. Press the "Rec" button again when the audio reaches the end of the portion.
Press pad 3 to play back the sampled audio. Select "Loop" to loop the sampled audio.
Connect the audio source to the line-in jack on the SP-404
Press the "REC" button to initiate sampling mode.
Press bank "B" and press trigger pad 10 to select it as the audio destination.
Press the "Lo-fi" button to select the audio fidelity of the sampled audio.
Press the "Stereo" button to enable stereo sampling.
Begin playing the audio from the connected source. Press the "Rec" button when the audio reaches the portion to be sampled. Press the "Rec" button again when the audio reaches the end of the portion.
Press pad 10 to play back the sampled audio. Select "Loop" to loop the sampled audio.