Flagship preamplifiers with separate power supplies are becoming relatively common at the ultra high-end level, and Jeff Rowland's new Criterion is the latest two-box model to join this elite group. The Criterion's power supply features an internal self charging Ni-MH battery pack, replacing the lead-zinc batteries used in Rowland's previous flagship preamp, along with several additional improvements. The Criterion has four balanced and two single ended inputs, and both balanced and single ended outputs. Both signal to noise ratio and channel separation are rated greater than 100dB.