All PrimaLuna products use massive, potted toroidal transformers. PrimaLuna transformers are enclosed in a metal housing and then potted in a non-microphonic resin to further reduce noise and to protect the windings from moisture and deterioration forever. Expensive and exotic preamps always use a dual-mono design to achieve a level of imaging not possible otherwise. Most manufacturers don’t employ dual-mono because of expense. It requires two power transformers, double regulation circuits, and in fact….everything is double. In effect, dual-mono means building two discrete and separate preamps into one box. It is so expensive to build, it’s a rarity even at the highest price points. All PrimaLuna preamps are dual-mono for the ultimate in stereo imaging and a sense of space that goes on forever. Specifications: Inputs 4x Stereo RCA Outputs 2x Stereo RCA, Stereo RCA Tape Out Gain 10.8 dB Freq. Response 15Hz-80kHz +/- 3dB THD < 0.2% @ 2V S/N Ratio 93dB, 100dBA Input Sensitivity 580mV Input Impedance 220kΩ Output Impedance 2800Ω Power Consumption 52 Watts Standard Tube Complement 2 - 12AX7 2 - 12AU7 2 - 5AR4 Dimensions (WxHxD) 11" x 7.5" x 15.9" Weight 30.8 lbs