Thanks - I might give that a go. I did manage to get MAME to run my spectrum games though - problem was that my laptop didn't have a Scroll Lock key. I plugged in an external keyboard, then once Load"" had run (see above), I pressed scroll lock, and then F2. This started the tape player, and the nostalgia kicked in with that noise.
A few other useful bits: Shift+F2 stops the tape. F11 shows how fast the spectrum is running (100% is normal - more is faster) and F10 toggles normal/faster.