Different cables affect volume? (NOT sound quality}

Hi All,

Will try to make this as clear as possible.

When i play a regular CD through an Audiolab 6000 transport, into a Bifrost 2/64 using COAX cable, the pleasingly loud volume setting (HD 600 cans) on either Valhalla2 or Asgard2 is about 12pm, Fine.

However, when I listen to the same CD(S) from my MacBook Pro (Apple lossless files) using the same Shiit pieces, but through TosLink cable to the DAC, I need to increase volume by about 3 full steps/hours. [Gain settings high in all 4 cases]

The compound question is: would switching to a USB connection from the computer change the signal strength (?), or is the issue further back in the "food chain."?

Just curious before spending /wasting money on more cables.

TIA

Richard