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Richard Thomas

Mac mini 2012 DC input specs

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I've bought myself a 2012 mac mini- I've seen the Gotham Sound DC conversion instructions, but am wondering what kind of tolerance it'll take voltage-wise...Will it be ok with a LiFePO4 battery hooked up directly or will it need a 12V regulator?  I've had a look at max current draw and it looks like it's 85W (8A at 12V should be enough)

Any experiences after having it done?

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You will have to contact Gotham directly for the real answer to your question. I have a Mac Mini that I was considering doing the conversion but not totally confident in my own ability to do this. I did ask at Gotham the exact question you asked: voltage range that is acceptable and whether DC regulation was necessary. The answer was no, DC regulation not necessary and acceptable voltage range was 11 to 16 volts. I'm not totally convinced since I do not know exactly where within the Mac Mini the voltage regulation occurs.

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davidm   

The Unibody Mac Mini's will run on a wide range of DC input voltages. The mod removes the internal AC supply and then makes a direct connection from an external DC supply to the Mac Mini's main board which no doubt has it's own DC-DC conversion. My 2010 and 2012 models would work just fine off the over 17 volts of a freshly charged V-Lock battery. However....

Depending on what is installed in the Mac Mini such as hard drives, SSD's and RAM, basic current draw can be in the range of .8 to 1.5 amps at 12 volts or 10 to 20 watts. If using a regulated supply, the crunch occurs during boot as current draw can peak at over 4 amps. If you are using a bus powered audio interface then you need to build that into the equation. The mains power supply is rated at over 80 watts to cope with the boot requirements and whatever the user has added in the way of external firewire and USB devices.

I ran a Metacorder setup for 10 years and found that I had to use DC-DC converters to fully float the Mac Mini power supply or there would be some level of bus noise introduced into the audio system. I used Traco converters and settled on 60 to 100 watt versions at 12 or 15 volts to get through the boot phase. My audio interface for most of the 10 years was a Metric Halo 2882 that was powered separately. A  ground lift firewire cable was required between the Mac Mini and the 2882 to be relatively noise free. USB bus noise can also be problematic. 

There are a couple of so called audiophile companies that have made filter and regulated DC supply boards that fit in the place of the AC supply but I haven't tried any of those. 

David

(2 Metacorder Licenses / Dongles for sale! PM if interested)

 

 

 

 

 

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14 hours ago, davidm said:

The Unibody Mac Mini's will run on a wide range of DC input voltages. The mod removes the internal AC supply and then makes a direct connection from an external DC supply to the Mac Mini's main board which no doubt has it's own DC-DC conversion. My 2010 and 2012 models would work just fine off the over 17 volts of a freshly charged V-Lock battery. However....

Depending on what is installed in the Mac Mini such as hard drives, SSD's and RAM, basic current draw can be in the range of .8 to 1.5 amps at 12 volts or 10 to 20 watts. If using a regulated supply, the crunch occurs during boot as current draw can peak at over 4 amps. If you are using a bus powered audio interface then you need to build that into the equation. The mains power supply is rated at over 80 watts to cope with the boot requirements and whatever the user has added in the way of external firewire and USB devices.

I ran a Metacorder setup for 10 years and found that I had to use DC-DC converters to fully float the Mac Mini power supply or there would be some level of bus noise introduced into the audio system. I used Traco converters and settled on 60 to 100 watt versions at 12 or 15 volts to get through the boot phase. My audio interface for most of the 10 years was a Metric Halo 2882 that was powered separately. A  ground lift firewire cable was required between the Mac Mini and the 2882 to be relatively noise free. USB bus noise can also be problematic. 

There are a couple of so called audiophile companies that have made filter and regulated DC supply boards that fit in the place of the AC supply but I haven't tried any of those. 

David

(2 Metacorder Licenses / Dongles for sale! PM if interested)

 

 

 

 

 

Brilliant- thanks David
I think it's mainly going to be running from a LiFePO4 battery, so should be good- and it's good to know it'll probably be ok off Li-Ion too 
 

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davidm   

My first G4 Mac Mini 12volt DC power setup was with a Carnetix system. The fan was a bit loud for my liking. 

The Carnetix powe supply was designed for the the G4 and early Intel Mac Mini's which needed around 18 volts to boot. Wouldn't reccomed for the 2010 onwards 12 volt Unibody Mac Mini's.

 

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