X2 units with x1 240v power supply that can power up to 3 units including cables. These pre amps sound amazing loads of great reviews on the web, Only ever had light studio use "smoke free" sad to see them go but i'm just not recording any more since moving. I would consider selling separately if you don't need the power supply for that one pre.The AEA TRP is a one of a kind preamp was designed specifically for use with ribbon mics, moving coil, and tube mics and has 83db of clean gain and no dangerous phantom power. The Ribbon Pre is one of the only mic pres out there designed exclusively for ribbon mics. The TRP is an ultra fast, two channel, minimal-path JFET preamp designed collaboratively with Fred Forssell. This unit is designed to have one of the lowest noise floors available. Eliminating phantom power allows for advantages in minimal signal path circuitry and the elimination of electronics that induce noise.The AEA TRP is the only mic preamp designed specifically for ribbon mics. Unleash your ribbon microphones' full potential with a TRP, and hear music more completely than ever before. Your ribbon mics will sound loud, clean and open, with fuller bass response.AEA's TRP has the quick, quiet gain you need for digital recording of ribbon, moving coil and tube mics. The Ribbon Pre has the speed needed for high resolution 192 kHz recording. With 300 kHz of bandwidth and DC coupled, Low-Energy-Storage (LES) circuit topology this preamp delivers outstanding dynamic response and bandwidth, and recovers instantly from overloads. TRPs have enough gain to let you hear how noisy the universe really is, but within the limits of physics, provide quiet gain. The DC coupled mic inputs let you hear all the dynamics, subwoofer bass and fast transients that your ribbon and tube mics can deliver. This discrete front end and integrated circuit JFET design combines the quiet gain of solid state with an openness reminiscent of tubes.