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The capcom play system arcade board has very muffled audio. I got tired of everything sounding that way. I followed the audio traces and disconnected all the low pass filters. Here's the mod:



Here's the before and after result:

https://www.youtube.com/watch?v=yw_vWAMbwUQ

With the help of tiido I learned how to transplant sound effects between cps1 games. I swapped the bass kick sound in street fighter 2 with the bass kick from megaman the power battle, it doesn't have as much of that high pitch ringing that the original sample has so it sounds better. Here's a playthrough:

http://www.youtube.com/watch?v=uObo8b4z ... e=youtu.be

Some instruments surely sound clearer, but it's clear why they did it when the audio samples play back. I recommend seeing how it is if you leave the low pass filter on just the µPD7759 6295.

mikejmoffitt wrote:Some instruments surely sound clearer, but it's clear why they did it when the audio samples play back. I recommend seeing how it is if you leave the low pass filter on just the µPD7759 6295.

Yeah the lpfs are just for the 6295. Without major low pass filtering the 6295 samples generate an annoying high pitch sound and the voice samples some like a machine. The yamaha chip sounds great without low pass filtering but the 6295 generates all drum and sfx samples so adding a low pass filter to the 6295 makes everything still sound muffled. I disconnected the 6295 from the circuit and wired the output straight into a rca jack it still had these issues I'm experiencing with it wired into the ciruit with low pass filters removed. This demonstrates that the issues have nothing to do with the pcb audio circuit. I prefer the sound without the low pass filtering. One of the drum instruments that was causing the high pitch noise was the bass kick. With the great help of tiido figuring out the 6295 rom format by reading the datasheet I managed to transplant the bass kick sample from megaman the power battle, reburn the rom, and the megaman bass kick doesn't generate nearly as much of a high pitch noise. Here's the result:

https://www.youtube.com/watch?v=-MjNcgyIXzE

The blanka stage music bongos still generate a high pitch sound. I removed the bongos from the sfx rom with one eprom but then it sounds kind of funny although there's no longer that high pitch sound. The blanka stage has a total of four bongo drum samples, the highest pitch bongo is also used in the dhalsim stage music. Later I may try the game again with the bongos removed and see which I prefer more.