Jun 282011
Some days ago, an update to CPCBox, a JavaScript CPC emulator, brought sound emulation to the emulator and now the second JavaScript emulator, Roland by Antonio Villena, features sound emulation, too. When I tested it, it seems a bit smoother than the sound emulation in CPCBox, so you should try it by yourself (use Firefox) on http://roland.antoniovillena.es/.
If you want to discuss the emulator, have at look at this thread in the CPCWiki forums.