Linear Power Supply for a MacBookPro

[gmgraves]

On 12/2/2013 at 12:16 PM, Gilles said:

Good day to all,

 

I read lots of posts on linear power supplies and, if I am not mistaken and my memory does not fail me, I find that the vast majority deals with Mac Minis.

 

I would like to know if it is feasible to connect a linear PS to a MacBookPro and, if yes, is it as simple as plugging the DC cable into the MBP's MagSafe port, or does this require internal mods to the MBP?

 

Comments and links to existing threads on PSs and MBPs will be greatly appreciated.

 

Thank you very much in advance.

 

Gilles

Well, the power supply requirements between a Mac Mini and a MacBookPro are quite different. The PS in a Mini powers the computer directly, but the PS in a laptop merely charges the computer’s battery. It’s the DC battery that powers the MBP. I doubt seriously if there would be any difference between a linear power supply and the MBP’s battery charger. 
HOWEVER, The PowerBook has feedback to the battery charger to keep the charger from overcharging the battery. Notice that the magnetic connector on the MBP has an orange led that’s lit when charging, but at some point, when the battery is fully charged, the light turns green. If you bypass this charging monitor function, you will ruin your battery very quickly.

[gmgraves]

1 hour ago, Ralf11 said:

why not do the cheapest and/or easiest option first?

 

use an external DAC that is isolated for noise, or use an isolation device to feed the DAC

The easiest is, of course, to connect to the outboard DAC is with optical. Depending on the year this MacBookPro was made, the headphone jack doubles as a Toslink port. The newest MacBooks have dropped that feature, but the series before the latest one still has it. You need an adapter that goes from a 3.5 mm headphone plug-like shape to a regular Toslink female, or a cable that has the 3.5mm connector on one end and a normal Toslink connector on the other. 
The optical interface isolates the computer from the DAC both galvanically and electrically. It is limited to 96 KHz but that’s what most Hi-Res is anyway.