The inexpensive SMSL SAP-9 is a great option for those looking to recable their headphones and discover the benefits of a balanced setup. Offering clean, clear sound, it features a fully independent balanced circuit with a separate TPA6120A2 amplifier chip for the left and right channels. When used in balanced mode, the amp delivers significantly more power; just note that the balanced and unbalanced output ports can’t be used at the same time. Plus, the SAP-9 is fairly compact for a balanced amplifier, measuring 4.75 inches on each side and weighing less than a pound. It comes with a 5-volt power adapter and a USB-to-DC cable.