Lewm, the space really isn't there for a second tonearm on-plinth, and if one tried, THAT would require major surgery on the plinth. If one wanted to put one on a pod behind the plinth, that might work, but it would have to be a loooong arm. According to the Pioneer tech who did the overhaul on mine, the existing arm can actually be removed and replaced quite easily without doing anything to the plinth/chassis. The replacement simply needs to be a very similar arm (282mm effective length or so, as long as the base-pivot relationship is similar). I would think the long Audiocrafts (4000, 4400), the Audio-Technica 1501, the Micro Seiki MAX-282 and MA-505L could be made to work, and I bet the long Sony arms (PUA 286, 1600L), and the long Victor and Denon arms would also work. I have not tried it (not sure if I would want to - as a straight arm, it works really well). I cannot, offhand, think of any modern arms with similar length but I am sure someone could find one or two. That said, the arm on it is pretty darned good. I would think it would compete pretty well with the best of the arms mentioned above (which if I had to choose, I would say is likely to be the Max-282, based on my experience with the Max-237).