Pretty sure in Gate of Thunder, the "voices" for power ups and some explosions are ADPCM. You can use sound check. Also, Pomping/Buster Bros all the sound effects are too...
I had a Duo with the ADPCM go out, too me a while to figure it out since I was playing a lot of HuCards at the time. Ended up mailing it off after feebly attempting to repair.