HI Crystalref,
beautiful system! i have owned Velodynes for almost 20 years. their line-in has historically been a superior connection imho. instead of a loaner pair of speaker cables, you may prefer to use an RCA connector into your Preamp that has two RCA outs. that way you can use one set of RCA cables into your CJ Amp and one set into the line-level input of your Velodyne. Given the size of your speaker, i think you could well find you prefer not to use the crossover inside the Velodyne but rather run the Velodyne in parallel. I own Sonus Faber Strads and have done this for years.
Hope that helps...certainly an easy thing to try and a decent pair of connectors is a few quid. Good luck and if you try it, let us know how it goes!!!