Which is the best upgrade for the money for steaming from lap to through amp?


I am looking to upgrade my system with either a line conditioner or USB/Digital cable.  Am budgeted to spend about $500.

I am current running a mac pro to a McIntosh MHA-100 Amplifier and headphones out from amp.  

So where will I get the greatest benefit in transferring the sound quality to my Headphone?  Form the Line conditioner to the lap top and amp or from the upgraded cable from laptop to Amp?
stephentp
Friend

MacBook Pro’s already have outstanding power supplies that include great power conditioning - which contributes to their stellar performance.

Your best bang for the Money would be a good Digital USB cable.   If your budget is limited visit Best Buy and get the  Audioquest Carbon; if not - look at the Wireworld Platinum Starlight 7USB 2.0 or the newer Starlight 8 USB 3.1.

McIntosh equipment is also stellar; so you are almost there as far as Sonics go.
Have you considered a USB to S/PDIF converter?

I use an old Macbook Pro, with Halide Bridge (USB to S/PDIF converter) to DAC.
All in one cabling is an advantage for me.
Also have an iFi USB Silencer.
At work have a M2Tech Hiface2, which was recommended to me.

I'm considering upgrading the Halide Bridge. It's limited to 24/96.
Although I have no 24/192 at present.
Also have

Have heard people talk very highly of Black Cat Silverstar Coax cable.