The Rockwell is a single ended amplifier with zero feedback, and it employs direct heated triodes for its power tubes. Like the ampsandsound Bigger Ben, it uses a 6SL7 input tube, and it is tube rectified. The out transformers are massive and over spec'd and provide five output impedances (8, 16, 32, 100, and 300). This allows you to match this amp to pretty much any headphone. Like the Bigger Ben, it has Jupiter capacitors, and input transformers, and one single ended input. Volume control is a very high quality stepped attenuator, and it has speaker binding posts on the back of it, making it an integrated amplifier.