If you are using or contemplating purchasing the Monarchy Audio SE-100 Delux or basic SE-100 amps, I would recommend using them with the Monarchy Audio AC-1 upgrade power cords. These upgrade power cords only add $150 ($75 each) to the retail price of the mono block amps, but significantly increase the level of performance of these already fine sounding single ended solid state amplifierss. You will hear a more open top end, an airier midrange and tighter, more detailed bass. For the level of performance gained, the AC-1s have to be considered a very inexpensive upgrade.