Try right-clicking on background, machines and arrows. Some not-so-obvious operations are listed here:

Creating Machines

  1. Double Click on background
  2. Select type of machine you want to create
  3. Give a name for the new machine
  4. Click OK

Connecting Machines

  1. Hold down shift and click left mouse button on a machine
  2. Keep the button down, move cursor on second machine and release the button

Changing amplification between machines

Click on an arrow between two machines and move mouse up/down

Changing stereo pan of a machine

All machines connected to master can be panned using the slider on the machine.