Super Famicom Low Audio

When testing a Super Famicom, I noticed its way softer than my US mini. Is this normal? I recapped it and there was no change in volume at all.

It could be the sound chip going bad, or your cables are getting interference from somewhere. My super fami and SNES volumes are the same, with no Mods done to them.

US and Japanese SNES PCB's were exactly the same aside from the power plug and case. It's probably a revision difference as there are some models that are pretty poor in the visual department such as the revision before the 1-Chip was released that came with the Killer Instinct bundle, it has the worst video output with interference and jailbars due to poor trace and IC placement. Wouldn't be surprised if there are any with inferior audio circuitry also.