MIDI files created at the TYROS; the PSR 3000 and the PSR S-series keyboards may use Mega Voices.
This voice type is not found at other keyboard models (or sound cards) which mean that these voices do not sound right.
This program substitutes Mega Voices with the best suited standard XG voice.
Mega Voice notes higher than note B5 are omitted, as these cannot be substituted properly.
This means that the conversion in some cases is rather problematic; and hence an individual revoicing might be required.
Conversion can be a one-to-one conversion, such as conversion of miles to kilometers, or Fahrenheit to centigrade. Such conversion can be carried out without loss of accuracy.
But conversion may require pre-processing or post processing to get the best results, most often performed manually. Think of converting images to other formats. To get the best result colour balance, contrast etc. should often be adjusted manually afterwards. Just like translation with e.g. Google. Results are usually somewhat understandable, but not perfect. Here you will also need manual finishing.
The same goes for converting with this 1-click program. The result of the conversion is useful - and in many cases fully enough - for the average user. But if the end result has to be 100% correct, there must be manual finishing in more advanced programs.