The radio shack mini amp is one of the most overrated underperforming ever... If you need plug and play there are better choices in battery powered amps on eBay and amazon.... If you can solder a couple wires then Carls electronics has Velleman and Canuk kit AMPs that will fill your needs.... The introduction of lower priced programable E callers has killed any cost savings, but I understand the itch to brew your own...