That's another feature that makes this "better than soundcloud" because they don't provide a volume adjust on their site.
Really annoying for those times when I've been playing soundcloud in the background with some other audio source in the foreground (like a video game, or even just mail notifications going beep)
yeah agreed, i have an in with some of the devs on this - the volume slider was a secondary feature and is on the list last time i heard, stay tuned (haha) for the next release,