Hi Rob,
The ATU-100 does work without modifications.
The power rating is somewhat optimistic since the component types/ratings are not necessarily as specified by the original designer.
It¡¯s possible to change various parameters that are stored in EEPROM memory, but a specific programming tool is required. The programmer is also required for any firmware updates.
There are several different versions of the ATU-100, some with all buttons fitted (Tune, Auto, Bypass) some with batteries and in pre-built or kit form.
It¡¯s probably a good idea to have a read of the user manual and look at some of the on-line reviews to see if the ATU-100 meets your requirements.
The manual is available from the GitHub link below.
73, Dave
