I hava opl3-sax card by Yamah.
sndconfigure will automatically detect it and set everything up.
I can hear both samples (the au smaple could be a little louder!!!)
but after sndconfig exits I get an i/o conflict error from the midi
module and midi does not work. The reason is the following
incorrect /etc/conf.modules file:

alias sound opl3sa2
pre-install sound /sbin/insmod sound dmabuf=1
alias midi opl3
options opl3 io=0x388
options opl3sa2 mss_io=0x530 irq=5 dma=0 dma2=7 mpu_io=0x388 io=0x370
                                                         ^^^

If I change this according to "mpu_io=0x330", everything works fine
except for recording sound.