The OP asked about Line Magnetic... I have an older LM 502ca that I've swapped its LM branded Electo Harmonix tubes out of for La Radiotechnique, Brimar and RCA clear top 12au7s; all are amazing tubes and ups the DACs performance exponentially. I use an Acrolink AES/EBU to my Lumin and an Audience AU24 Coax to an Enlightened Audio transport and it, on many days, outperforms my other tube DAC costing twice as much. If you can get your hands on one, grab it.