Connect an audio interface to your computer.

1. Install kxstudio sources

# Update software sources
sudo apt-get update

# Install required dependencies if needed
sudo apt-get install apt-transport-https gpgv wget

# Download package file
wget https://launchpad.net/~kxstudio-debian/+archive/kxstudio/+files/kxstudio-repos_11.1.0_all.deb

# Install it
sudo dpkg -i kxstudio-repos_11.1.0_all.deb

2. Install Cadence

sudo apt-get update
sudo apt install cadence

3. Start Cadence and open Catia

Press WIN and search for Cadence. Press Start Button. Open the Tools-Tab and start Catia.

4. Install Reaper

Download from https://www.reaper.fm/download.php

Extract tar.

cd reaper_linux_x86_64
sudo bash install-reaper.sh

5. Start Reaper

Press WIN and search for Reaper.

6. Find Reaper in Catia and look at the wiring. Reaper should be connected to your audio interface.

7. Add a new track to your reaper project.

8. Press the red record item on the track to activate the track for recording

9. Select the proper channel, right below the record button. Connect an audio source, e.g. guitar, microphone, synth to your audio interface. If the correct channel is selected you should see the audio signal on the tracks input meter.

10. Press the record button at the bottom of reaper to record.