In practice:
The upfader being graduated from 1 to 10 will allow us to lower the volume little by little. Note that we are looking at the fader and not the vinyl.
For the scratch echo proceed with these steps:
We start with the fader closed (so at 0), then we open it to the maximum (10).
At the same time we launch the vinyl.
For the moment it's the forward scratch except that we don't use the crossfader.
Then after the desired sample length, we close the fader.
Then as for the forward, back to the starting point of the vinyl.
To get the echo effect, set the fader to 8 while sending the vinyl.
In this way, we get the same sound at a lower volume.
Let's continue the operation until the sound goes out, and we get an echo with the sound.
On the right you can see the graph that illustrates the operation in time.
Note that the fader position will vary depending on the mixer used.
However, the tables with the fader stroke adjustment will help to create the effect.
Finally, you can use the 2 audio files to practice, or follow the Q&A at the end of the video.