Bad sound in Virtual Box in recent builds
Its been pointed out to me that if you use Virtual Box and Solaris guests with recent builds (say newer than 124), that you might get a bad sound in the Solaris guest. Turns out that the problem is that the Boomer stack has increased its timing accuracy to a higher limit, beyond what Virtual Box can provide. We're going to fix this properly soon... but in the meantime, you can just edit /kernel/drv/audio810.conf and change the play-interrupts to 30 in the guest. This is CR 6901849 in case anyone is tracking it closely.