I'm using the Lepai LP-2020TI for my MAME cabinet, sounds amazing. But, for my JAMMA cabinet, some of my non-JAMMA boards require an amplifier so I've been throwing these on the adapters I make TDA7297 15W*2 AC/DC 12V Digital Audio Amplifier. They are about $5 each, sold in packs of two for $10. Sound is great and they are very compact.