I don't often make claims about synergy as it is so subjective and individual specific, but the one claim I will make in this area is that the HD595 and the Bithead really sound great together for whatever reason. IMO, the HD595 sounds OK out of most anything but has a signature that is specific and unique to it, and coupled with the wrong amp (like a high impedance receiver jack) it really sucks. With the higher end amps IMO the 580/600/650 series seem to scale well, and the 595 benefits but not to the same degree. But for some reason I cannot understand, the 595 and the Bithead just "get it on" together. For a high value budget system I highly recommend the combination.