Magicbus. As in any other component in your system, unfortunately, there are cost factors. In my experience, as a general rule, the lower the cost of the tube pre amp the lower the resolution, the lower separation of each instrument as played in the space recorded, accentuated inaccurate bass response, and more limited sound stage depth. Clime the ladder though and you will be amazed at the transparency the Odysseys amps are capable of. If you have planar speakers though I would heartily recommend the solid state Tempest. It has the same quality of the power amps that should be illegal at its price point.