Single-Ended Triode OTL Headphone Amplifier * Zero Feedback * High Quality Parts Don"t compare Valhalla to cheap tube amps using open-frame carbon pots and substandard parts. Compare it to tube amps using Alps Blue Velvet pots, Dale resistors, Wima capacitors, and other top-end components. Also consider that Valhalla has almost 2,000uf of filter capacitance in its oversized power supply, for superior performance. * All Tube, All The Time The only active devices in the audio signal path in Valhalla are tubes. The 6N1P triodes input provides linear, low noise voltage gain. The 6N6P triodes provide good power output capability for a wide variety of high-impedance headphones (though, if you"re looking at orthos, check Mjolnir, Lyr and Asgard instead.)