OK, got it working.
First, you have to match the ROM version with the MAME version. I'm not sure what you downloaded with "MAME 2018", but that's probably not matching the ROM you got.
You can find previous versions of MAME here:
https://www.mamedev.org/oldrel.html
I'm using 0.185 now (the ROMset for this is available on archive.org).
Put the avsp.zip file in your ROMs folder.
Also download the qsound.zip file from the ROMset. Place this in the ROMs folder as well (don't place it within the avsp.zip file).
It should work then.