Hey, I’d like to reactivate this thread. I’ve been working on migrating an earlier 3.x setup to a Raspberry Pi 3 with the latest Jessie bits, and I pretty much have everything working, except I am hitting exactly this same 5-second delay thing in Advmame. This occurs even on the Pi 2 using the same SD card, so it’s not a Pi 3 specific problem.
I notice that the delay occurs in both Advmame 1.2 and 1.4, and not so much in 0.9, as was described above. However, I got exactly nowhere in terms of curing it via any of the steps above. I can even blacklist snd-bcm2835 so that the built-in sound driver never loads and the _only_ ALSA sound adapter is the USB one, but I still get the big delay. However, I also noticed that it seems to somehow be related to emulator startup – sounds that occur right after boot (for example in the btime ROM) play at a lower pitch than they should. This gave me an idea, and I started playing around with the various latency and sound sync options in the .rc file, but I still didn’t get anywhere, until…
If I use “debug_rawsound yes” option in the advmame .rc files, then yes, the problem seems to go away. However, as this disables the sound sync code altogether, I suspect that the sound will start to drift over time, so I wasn’t thrilled with this being the actual solution. Finally, I just changed the sound option to use SDL instead of ALSA, and that seemed to fix it as well.