[Theodores]

Some of those sound effects are AY-8192 sounding to me, explosions on the spectrum were never like that.

[Narishma]

They added an AY chip to the Spectrum starting from the 128K model I think. It was also available as an add-on to the original 48K.

[chipsy]

The Spectrum 128 contained an AY-8192, so you are right on the money. Earlier models were beeper only.