Have you tried both orientations of the Freys, i.e., with the arrow pointing toward the preamp as well as toward the power amp? The shield is presumably grounded at only one end, so hum pickup could very conceivably be sensitive to the direction in which the cable is connected.
Unless you have specific information defining the meaning of the arrow that is marked on that particular cable, I would not make any assumptions as to what it signifies.
Regards,
-- Al
Unless you have specific information defining the meaning of the arrow that is marked on that particular cable, I would not make any assumptions as to what it signifies.
Regards,
-- Al