That's VERY unusual! Does the cable have a network box? Does the cable have black mesh on the outside? A photo would help. You can email me through Portal Audio's website. To answer your question, the nominal input impedance of the Stingray is around 50 k ohm. The optimum MIT i/c cable for this amp would be set to Medium. All else being equal, your LOW cable might be performing at 96% - 98% of what the same model of cable in Medium might. BUT the differences would be subtle, not night 'n day. Hope this helps.
ATB,
Joe
ATB,
Joe