Mac Mini PSU Upgrade

Hi JC,

this sounds very interesting, can you please provide some pictures.

I assume that you 'pimped' an old version of the MM. From my side I have seen some enhancement when streaming music from a ram-disk rather then a hard-drive or thru networked storage/servers.

Best regards
be4

I sprayed mine sky blue. Now it has much better depth and resolution with an indefinable air around the notes.

Sounds like it would've been easier to just build a new one. There are so many power supplies available...

JC,

What was the output voltage?

Using the NP Blackgates will not really do much. A better bet if the voltage is under 10V output would be the BGN 1500uF/10V units. Or some of the organic caps which are much better for switching supplies like the Elna RFS or the UCC units.

Really I have been thinking of a hefty linear unit for the Mini and some of the Western Digital drives.

Thanks
Gordon

Hi Gordon,

The output voltage is 18v @ up to 6amps.
The Blackgate was a BGN type.

Regards

JC

Now I really don't know if this is a spoof or not. What is the point of upgrading a Mac Mini's power supply?

Hmmm ...this goes back to that XXHighEnd conversation. The Microsoft techie felt that, in theory, processor use COULD cause a drain on the power supply which in turn COULD therefore affect your audio playback. Somebody tell me I've over simplified that ..
It could be measureable ... would it really be audible - if it was even measureable ?

Can you back up the advantages of the new power supply with any stats? I'm struggling with this one now ... (and am waiting for someone else to post some stats too)

M.

Just realised I'm typing away and not listening to any music. tut tut.

"Had to saw the case open though!!!!" <<--- eeek!
Thought the Mini could be "unclipped" ... ?!!

Gordon,

If you build it, I want it! The Cosecant is great.

What are your thoughts on battery power...for the Mini or DAC.

JC,

The BGN are not a real good idea in this area. What you need is the organic ultra low ESR's to kill all that high frequency crap. The BGN are pretty high ESR.

I would look at using some of the UCC APS models but I don't see any 20 or 25v available anywhere.

http://app.arrownac.com/aws/pg_webc/0,1086,,00.html?application=SEARCH&a...

Maybe the ELNA RFS these have low ESR like 0.1, unlike the UCC which are usually like 0.008 ESR. Do a search on DigiKey.com for ELNA RFS. I have the ESR curves for these somewhere when we did them.

Remember when it comes to switching supplies... more is not neccesarily better.

jtwrace,

Well batteries are good in places. I am not sure it would pay to try and make a honken large supply for the mini. The Cosecant would be fairly easy but I am not sure your going to see one of these soon. It would really require something that told the Battery pack to charge and run. That's what we do in the Crimson.

Thanks
Gordon

BEEMB,

While the Mac Mini itself can be "unclipped" with a putty knife, the power supply for the Mini is a separate Brick that is sealed, much like an iBook or MacBook AC Adaptor. To get into these devices requires some warranty voiding semi-destructive disassembly. The reason for this is that Apple doesn't really want folks tampering with potentially lethal voltages, protecting their customers for harm and their company from liability.

IF a change in the PS can result in better performance, I don't know why someone wouldn't just produce something in a separate chassis and fit the same PS plug that Apple uses. Of course, I am sure that the PS connector on the back of a Mac Mini is NOT a standard part!

ATB,
Tom "TJ" Jankowski

"IF a change in the PS can result in better performance, I don't know why someone wouldn't just produce something in a separate chassis and fit the same PS plug that Apple uses."

Someone is will :~)

I assume this isn't a spoof.

So how does upgrading the power supply improve the computer? Especially given that a considerable load is removed from the PSU if no graphics is in use (depending on model) when the mini is used headless. What specifically improves by fiddling with a PSU which is already designed to do the job, isn't required to drive varying loads (like an amplifier PSU) and can even be isolated from subsequent components in the chain by using an optical out rather than self-powered USB?

I do hope we are not heading in the direction of green marker pens and frozen CD's. If, and this is a big if, if a power supply upgrade was likely to improve things, then, as Chris has just pointed out, we would come across an external bolt-on by now.

JC,

I was looking over at eBay for a dead psw as all I want is the cord. Are all the power supplies the same pinout?

Thanks
Gordon

Just to clear a few things up.
It is not a spoof...I really did this. Am I mad?...Oh YES.... Am I stupid?...Undoubtedly...
I REALLY did saw the case of my Mac Mini POWER SUPPLY open. I tried to unclip it but could not. So out came the large Hacksaw...new blade at the ready and hey presto after a few hefty hackings the power supply case was off. Next up was the removal of the thin aluminium sheeting which was impeding the access to the delicate innards of the power supply. Out came the industrial sized sheet metal snips. These made extreeeeemly short work of the task. NOW the intimate innards were exposed....MMMmmmm.

See the cheap capacitors glinting in the pale light reflected off my large, bald, misshapen head. Watch as they are removed with the white hot Weller number 22 chisel bit. I gleefully snort the acrid fumes arising from the blackened Pcb and the molten components nearby.

I scurry in to the next room, my precioussssss Black Gate capacitors are stored here, away from the jealous green eyes of the poor ones. I carefully weld them into the mass of carbonised remains. The whole thing is levered into a new case, the wires are re-attached and the unit is plugged into the wall socket and the non-sawn open Mac Mini... The little rear button is caressed and it bursts into new life......My precioussssss is working, it sounds better....I am happy....

Gordon.
Thanks for the info and tips on caps etc....I will be having a look around for other ones to try, now the whole thing thing is easily accessable I can do measurements etc..... The plugs I am not sure about though...I think they would be the same... For your info, there are 4 wires in the DC out cable.. +, -, screen and a very thin wire poss used for some sort of sensing, shutdown etc....

Why bother putting a battery or uprated supply on a Mac Mini when a Macbook is practically the same machine with .. um a battery.

Dangerous things these CD colouring pens, particularly if you sniff 'em.

JC,

Yea I am thinking about doing this maybe for my show system. I will grab a PSW off eBay and then hack into it. I did some designs for a linear that would also power my Western Digital 1T drive.

Thanks
Gordon

This is a dumb question undoubtedly, but can one just replace the external stock power cord with a power supply from someone like Paul Hynes? (or is it necessary to be replacing the internal cap's to have the optimum effect). Could also toss on a large Infinity box from Alan Maher on top which would probably also tame the noise/interference after settling in a few days.

The psu is 18.5v @ 6.5a as far as I remember...but is has this extra little wire connected which probably is some sort of sense wire??? not sure.. I am sure a Paul Hynes design would be a much better job though.

Regards

JC

Having just bought a new mini as my Amarra/iTunes music server, power upgrade was high on the list. Have coordinated with Wayne at Bolder Cable, and they're customizing their Squeezebox power supply to work with the Mac Mini. Will be at 18.5v, and will also deal with that pesky mac mini "iSense" wire in the power cable required to operate.

this unit: http://www.boldercables.com/servlet/Detail?no=395 [or course folks can go all out with their "Ultra" model, but that exceeds the cost of the Mini]

this cable: http://store.mp3car.com/MacPac_Power_Cable_Kit_p/cbl-002.htm [just using from this kit what is needed]

Gordon....if you are still looking I have a dead Mini PS....need to check if the plug is the same but you are welcome to it....I didnt realise it was dead when I bought it....send me postage and you can have the brick as well...

So the question is will the Mac Mini sound way better with a better quality power supply?
It looks like this thread has been on idle for some time.... So does anyone have some new info???

Phil
Santa Fe

Mac Mini 2009/ Amarra/Wavelength Brick/Apogee Duet/Apogee Ensamble/Variuous home made DAC's/Home made 2A3/45/300B anps/ First Watt J2/ OB Feastrex speakers/ various PS wires etc etc.

Here is the schematic for the Mac Mini Cable.

I don't see it

Nope... Ill try again

Thanks!!!!

Would a linear lab PSU with a variable output (0-40v.) and able to deliver up to 10 A. do the job, or does a suitable PSU has to incorporate some special components or circuits to really provide some improvements to the Mac Mini versus the OEM switching PSU ?

makes a power supply for the mini.

http://www.boldercables.com/servlet/-strse-412/Power-Supply-for-Mac/Detail

not much info on it though....I would call them and ask!

Jesus R
www.sonore.us

Big Lab supplies are expensive, heavy and most are simply wonderful....BUT you can seriously screw up a fine piece of gear if you do not know exactly what you are doing. For an example: Say you plug in your nice new Mac Mini to a big ass lab supply... You then turn it on the lab supply then power up your Mini. Seems simple right?
Wrong, you just cooked your mini.
Logic Boards have ZERO sense of humor when it comes to OVER VOLTAGE. Because a lab supply can be adjusted it is very easy to make a simple mistake and apply 26 (or more or less) volts instead of the 18.5 required by the Mini. 26 volts will, in micro seconds, cook a fine variety of parts in the Mini. The CPU, RAMs, ROMS, etc etc. You won't even see smoke... and no, the fuse thats installed on the Mother board will not pop. Your left with a totally useless machine. Very sad.

But on the up side...
The Mac Mini draws about 2 amps give or take... depends on how much stuff you have plugged into the ports etc. wifi blue tooth... Load it up and maybe 4 amps...I really do not know But the switcher ps that comes with the mini says 6 amps at 18.5 volts dc. So for my money I got a Sorensen 40-6. (0-40 volts dc and 0-6 amps) The cool thing about the Sorensen is OVER VOLTAGE protection. Set it to 18.5 vdc and that it... No More. I think I paid 200 bucks for it from John Bau here in Santa Fe...
So of you might remember John... Spica speaker guy!
Link to his site: http://www.users.qwest.net/~jbau/tstequip.htm#GPIB%20Stuff
Great Guy, wonderful used test equipment etc.

So how does one of these B.A.P.S. sound? Its like the difference between a new High Def flat screen tv and and old analog picture tube tv's, It is huge. Power supplies rule audio. Kinda like salt rules cooking. Lousy Supply equals Lousy Sound.
And it is my opinion that most "Audiophile" gear sold today lacks proper P.S.
But I might be wrong...

Phil
Santa Fe

Pix

It over kill but
Its inexpensive and really good.

And a fantastic deal! thanks for sharing, I'm sure some others will follow your path. I too found the leap to linear PSU with the Mini to be a big leap forward in SQ.
Best!

I am seriously lusting after that Antelope 10m Atomic Clock!

POWER SUPPLIES AND CLOCKS...OH MY!!

You're on the right track, Phil! It's only just beginning to be understood that computers need better PSUs in exactly the same way as any digital transport or DAC.

A linear bench supply is a good place to start: the Intel Atom-based boards we use deploy a modified version of a similar supply: it's a key component for optimal quality.

Phil,

No Sorensen available here in France, but what I've in mind looks very much like : a 2x20v. - 10A Voltcraft linear lab PSU, with digital voltage setting and protection alike. Anyway the upper limit being 20v., I don't think I may fry my Mini if for whatever reason the voltage control fails.

But thank you anyway for the info.

My music is on a 4 To HD unit (2xTo in Raid 1), I'm also thinking to work on the PSU of that unit. Later, when it will become more affordable for large capacities, I will convert the storage unit to SSD, what I've already done on the Mini, with significant audible improvement.

I agree with you all : power quality is key !

Hi!

I agree that power is really important so I tried the MacMini from battery.(18.5V 3700mAh LiPo)
The result is fantastic.(More detail, more relax)
The original idea can be found here:
http://www.cs.duke.edu/csed/openwiki/doku.php?id=artsi:smurv
http://www.pamurray.com/manga/macbat-index.html

Here are my solutions:
http://vlaca.blogspot.com/2010/06/macmini-akkurol.html

The latest Mac Mini have an integrated power supply. I think it's going to be more difficult to tweak them ! Has somebody started to look into it ?