I've tried Ultrasound emulation many times with different builds but I never got it working (it sounds like samples start playing but very soon some random data gets played). I just tested ykhwongs latest SVN build (20101030) and the problem was still there. I decided to do some testing with different DOSBox settings but nothing helped. Then I finally found out what the problem was.

I have always tested GUS emulation with Dual Module Player 4.00 since it is my favorite MOD player. It turned out that Use DMA for sample downloading must be set to No from DMP setup. I have always set it to Yes like I do on my retro PCs.