You could try building your own cables, but with this style of amp both conductors NEED to be exactly the same and the +ve and -ve conductors would need about a 1" gap between them to avoid induced noise - the only real issue is maintaining the gap for the length of the cable.
But to accomplish the spacing I would fist start with a "Dollar Store" design, just to see how well this approach works
- Buy some "alphabet blocks" that children play with - like these
- Joqutoys 1.65” ABC Wooden Building Blocks, 26PCS Stacking Alphabet Letter and Counting Block Set with Storage Bag for Toddlers, Stacking Blocks - Amazon Canada
- Buy some small screw-in eyelets - like these
- CEEYSEE 300 Pcs Small Screw Eye Mini Screw Eye Pin Peg Self Tapping Screws Hooks Ring for Arts Crafts Projects (YJY1), Screw-in Hooks - Amazon Canada
- insert an eyelet on opposite sides of the block
- thread each wire through the eyelets on the blocks to maintain spacing
- Connect the wires and space the block evenly
- This approach will also hold the wires off the floor - bonus :-)
Once you hear the results you can fabricate a more "attractive" method of maintaining the spacing
PLEASE NOTE - I have never made this type of cable before, so I am just brainstorming here, but based on my experience with the Helix cables I believe it would work very well
BUT if you want a commercially available cable, other than the Fidelium, one of the best cables for this style of amp would be Nordost, from the HEIMDALL 2 model and above, because they are low inductance AND low capacitance and should achieve a very good signal transmission with this type of amp.
Regards - Steve