You need the converter only to get started.
Because you will see all log messages.
Theoretically, if you are enough experienced you can manage that task ( Linux configuration, administration) without a serial console.
For example, using telnet,putty, etc. over network connection.
To get started at the 1st time I recommend to use the converter. This is the simplest way to get access to Linux console even if the system is not configured correct.