MTH did not convert PS-1 sound file to PS-2. PS-2 5V sound files where made for PS-2 engines. Then when they shifted to PS-2 3V boards they created PS-2 3V sound file with it. Then they released the PS-2 3V upgrade kit. At that point it also became the repair board for PS-2 5V. So original 5V sound files were converted to 3V format. Additionally these converted or direct 3V file would be posted as upgrade files for PS-1 engines. Pretty much everything MTH made as PS-1 was made later as a PS-2 engine of one or the other format, or both. But PS-1 SF PFA sequences are unique, or the sound for a specialty engine is unique.
Now we are into PS-3 upgrades and you can use PS-3 or PS-2 3V Sf in the upgrade. So if you like a PS-2 3V or PS-3 Sf, you use it to upgrade your PS-1 engine. G
