AV Famicom sound confirmation

[dylbob42]

I have two AV Famicoms, one stock and one nesrgb modded and just recently noticed some odd behaviour where it comes to sound.

Because im now running the sound through my stereo (instead of just using the built in speakers in my 12" pvm, i never turned up to high because of audio hissing) im now noticing that some sound effects interferer with the music, either cutting out or causing the tone to drop lower.

Is this normal and i just didn't notice it before? It's hard to believe they both have the same fault, i even tried restoring the modded fami to stock to be sure and even got the sound directly from the cpu but its the same on both. For example going to the first stage in SMB3 and getting the leaf and spamming the tail, seems to trigger the music to do odd things.

 

[HVC-Man]

It could be some sort of impedance issue with your stereo.