Hi, RetroRalph.
Can you implement DPCM Pop reducer to Retrocopy?

from Fceu doc:
Why do some games make a popping sound (Batman, Ninja Gaiden 3, Rad Racer 2, Final Fantasy 3)?
These games do a very crude drum imitation by causing a large jump in the output level for a short period of time via the register at $4011. The analog filters on a real Famicom make it sound decent(better).
I have not completely emulated these filters
(Xodnizel)

info:
http://nesdev.parodius.com/bbs/viewtopic.php?t=3443&start=0

NSFPlay/NSFplug, NotSoFatso have checkbutton "Enable $4011" register.
When it disabled, DPCM Pop reduced

Just listen:
http://www.megaupload.com/?d=FB8UG68F

http://imageshack.us/photo/my-images/191/4011.png/