Review: Bolder Mac Mini PSU

silverlight · « **on:** 12 Oct 2009, 12:55 am »

Well, a long overdue write-up of the Bolder PSU Wayne made for me for my Mac Mini a couple months back. I was prompted to pull out the Mac stock PSU this weekend at the request of another AC user who is thinking about getting one and was curious of the improvements (I had never used the stock power before, so didn't know what I was missing). Bottom line, a very meaningful improvement in sound quality in so many respects, and I heartily recommended the upgrade.

I use the Mac Mini as a headless install in my audio rack in my main system running Amarra. Connects to a Weiss DAC2 via firewire to a Berkeley Alpha DAC using a Kubala Sosna emotion XLR AES/EBU, then to a Cary SLP-05 pre, then to amplifiers (either Spectron Musician monoblocks or Cary CAD-211 FE monoblocks), all interconnects and speaker wire Acoustic System Int'l Livewire. Speakers are Celestion A3's borrowed from the HT while new speakers in transit. Tested with a handful of different tracks including Mi Tierra (a wonderfully recorded track from Uncompressed World Vol. 1), You Do (Aimee Mann / Magnolia), As It Rolls to the Sea (David Grier, Live at the Linda), couple tracks from Rodrigo Y Gabriela's 11:11; Crow on the Cradle and Hop in the Truck (a couple 96khz tracks from Blue Coast Records).

So to the most important part, how did the sound change? The most noticeable change was the significant increase in separation between the instruments and the improved resolution/clarity. The decay after the initial attack in instruments was extended much further to a far more natural duration (vs flattening off rapidly). On soundstage with the Apple stock power the envelope of the soundstage was in front of me and spherically around the speakers. With the Bolder PSU I was well inside the soundstage at the listening position and it extended behind me (and I'm almost at the back against the wall).

So a worthy addition to the Mini if you're using it as a music server in your audio setup. A++ and if you're really into getting improvement, I'm sure Wayne will build the higher grade version of the PSU. I'm posting here in the Bolder circle, but anyone should feel free to link to it from the Apple circle, or CA.

TRADERXFAN · « **Reply #1 on:** 12 Oct 2009, 01:02 am »

Hmmm, not that I doubt the outcome, but curious if it would have been a bit fairer comparison if the original power supply had been used for a while?

silverlight · « **Reply #2 on:** 12 Oct 2009, 01:39 am »

Quote from: TRADERXFAN on 12 Oct 2009, 01:02 am

Hmmm, not that I doubt the outcome, but curious if it would have been a bit fairer comparison if the original power supply had been used for a while?

Good point. I had thought of that too, wondering if Apple's PSU required break-in. Lefit it on running the computer (running music/processes) continuously for about 48hrs before listening critically to the differences. Certainly could close the gap further with more usage.

konut · « **Reply #3 on:** 12 Oct 2009, 01:47 am »

Cost?

silverlight · « **Reply #4 on:** 12 Oct 2009, 01:54 am »

Quote from: konut on 12 Oct 2009, 01:47 am

Cost?

Wayne used the Standard Linear Power Supply for my setup at I believe 18.5V (http://www.boldercables.com/servlet/Detail?no=395). Plus the custom cable required from the PSU to the Mini. I'd defer to Wayne what the total unit + cable is.

Wayne1 · « **Reply #5 on:** 12 Oct 2009, 03:26 am »

Thank you for the review.
I have yet to hear much change in stock switching power supplies over time.

The power supply I built for silverlight would sell for $475.00. The cable for the Mac Mini would add roughly $100.00. It would be built in a smaller case.

I could also build an Ultimate Power Supply set up for 18.5 volts. That would cost $1000.00. It would have to be built in a larger case.

Wayne1 · « **Reply #6 on:** 15 Oct 2009, 03:43 pm »

The power supply for the Mac Mini is now listed on the BOLDER Cable Website.

It will sell for $575.00 including the custom cable designed to work with a Mac Mini.

Please allow 3-4 weeks for the power supply to be built.

Mac Mini Linear Power Supply

Wayne1 · « **Reply #7 on:** 11 Jan 2010, 05:16 pm »

I have received some more interest in the MacMini power supply.

I am currently working on a new case to be used with it. I had some requests to offer multiple DC voltage outputs so one box could supply the MacMini and a DAC, for instance. While I could just add another regulator circuit for the different voltage, I think it would be best to build an entire separate PS inside the box.

Using another transformer and PS circuit would raise the price quite a bit, but it would remove any possibility of one item send noise back into the supply of the other.

Ballpark price with a very nice case would be in the $850-1000.00 range, depending on parts and circuits used.

Would there be much interest in such a product from AC members?

silverlight · « **Reply #8 on:** 11 Jan 2010, 07:57 pm »

As a quick update on my Bolder Mac Mini PSU, I have noticed some nice improvement in sound by making two changes: (1) fuse, and (2) power cord leading into the unit. The biggest bang for the buck tweak was the fuse. I replaced the ceramic that came with the unit this weekend with a Furutech fuse, and there was a very material improvement in transparency and detail retrieval. really cool!! A no brainer investment of $40 or so if you have or are thinking of getting one of these.

Wayne1 · « **Reply #9 on:** 11 Jan 2010, 08:07 pm »

Very interesting.

The fuse I use in the power supply is a Cryo-Treated, Silver Plated Acme Audio one. In the past I have found that fuse to sound "better" than the Hi-Fi Tuning fuses.

I'll have to look into the Furutech.

DeadFish · « **Reply #10 on:** 12 Jan 2010, 03:27 am »

Do let us know if you develop a change of opinion after checking out the Furutech there, Wayne!

Best Regards!
DeadFish aa

astarock · « **Reply #11 on:** 10 Feb 2010, 05:39 pm »

Hello! I'm new to this forum. I have just received my Bolder PSU for my mac mini. Thanks Wayne! This thing is build like a tank.

Didn't have time to carefully listen for any improvement cause i had no ac power cord for the thing. Finally i found an old ac power cord that came from an Samsung computer LCD pannel. And that brings me to some questions. 1= I'm in the process of finishing my hifi computer music server built, Shunyata Hydra 8 and Python power cable, mac mini + bolder PSU, berkeley alpha dac(comming soon), rotel stereo amp, Vienna acoustics Beethoven concert grand, and whithout being on the cheap side, would i get improvement from putting a hifi ac power cord, maybe not as radical as a python, instead of a cheap computer cable.

2= Speaking of a cheap computer cable, in the mean time, can it be problematic running the bolder with this cable(18 AWG)?

3= I read from this post about furutech fuse, beside reading the fuse rating on itself(frankly, i can't read it on mine) is there any way knowing with fuse i need so i could change it for a furutech one.

Wayne1 · « **Reply #12 on:** 10 Feb 2010, 05:48 pm »

I do not include an AC power cable because most everyone has one or more laying around. Aftermarket power cords are very personal. What works in one system may not in another.

I do build good AC cables at a very reasonable price.

I have noticed improvements with different power cables with my music server. It is likely you will too.

The fuse that is included in the MacMini PS is an Acme Audio, silver plated, cryo-treated, ceramic fuse. The rating is 2 amp quick blow.

I do have a Furutech fuse here. I have not had the opportunity to compare it to the ACME yet, but I do plan to this week.

silverlight · « **Reply #13 on:** 11 Feb 2010, 04:47 am »

@Wayne - look forward to hearing your impressions of the Furutech fuse. Make sure to give it a day or two to break in, which is both advice I received and what I experienced when I added them throughout the system.
@astarock - welcome to computer audio! good choices! Out of curiosity, how are you converting USB or firewire from the Mini to AES/EBU on the Berkeley? Weiss and Wavelength both have great options. I started with a Berkeley and ended up switching to an Amarra Model 4 (now a little less $ when you add conversion to the BADA) to get to a single box solution and a couple of other features I liked (inputs, word clock input - just added Antelope external clocking with great success), and they sound a little different too, personal preference and system matching.
I also found sound quality differences in how I fed the PSU, a stock power cord vs several others I tried that I had around here. Ended up also sticking an Alan Maher quantum IEC filter in front of it too just because I had it lying around and not in use after moving my DAC to battery power and it also had an impact. But with the great quality of the Bolder PSU I suspect, I've found less variation/impact with power cords than I have found with DAC's or amps.
Good luck and happy listening!

astarock · « **Reply #14 on:** 11 Feb 2010, 10:49 pm »

Thank you guy's for such a quick reply!

@silverlight; about the berkeley alpha dac. No i don't have it yet. Will get it this summer. And as for how i would connect the mac mini with the alpha dac? Well i'v read in another thread that Berkeley audio design themselve are working on a kind of external converter(usb to AES/EBU) made for their alpha dac. So in the mean time i have to decide to temporarily go with the optical Toslink, with an HIface from M2tech, or with empirical audio offramp 3. Not sure about with one cause i want usb to BNC or AES/EBU 24/192 asyncronous and presently as today there is no such thing that exist.

Question! I'v check about furutech fuses and it seems that there made only slow blow fuses. Now, and stop me if i'm wrong, Wayne said earlier on this post that it uses ACME quick blow fuses for the psu, and the way i see it, your not suppose to replace a quick blow fuse with a slow blow one. If some one can enlighten me!

Thanks!

Wayne1 · « **Reply #15 on:** 12 Feb 2010, 03:37 pm »

As a general rule, one should use the same size and style fuse. As I am the one who makes the unit, I can push the rules a bit.

In the case of THIS power supply, I deliberately underfuse the unit for safety. There is enough leeway that you can use a 2 amp Furutech fuse safely. This is for THIS unit only. Consult with the manufacturer of any other gear you may think about changing the fuse.

deho · « **Reply #16 on:** 26 Feb 2010, 06:59 pm »

I'm more and more intrigued by the improvements that a stronger power supply can bring to my Mac Mini used as a music server and linked by USB to Audio Research DAC7 -> Ref3 -> VS115.

I found in my past experiences that a stronger linear DIY power supply did improved significantly the musicality of a Squeezebox, then I changed it for a ZardoZ (an Apple airport express modified by Db-System "http://www.db-system.fr", the main mod being an oversized power supply, again ...) ... So what's about the Mac Mini I now use ? What is the rating of that power supply ?

A question that also comes to my mind is if I should change the switching power supply of the 2 gig hard disk which feed the Mac Mini with my iTunes aiff music ? When it will become more affordable and available in larger sizes, no doubt that I will look to SSD.

All advices are welcome.

Thanks and best regards from rainy Paris.

Construct · « **Reply #17 on:** 1 Jul 2010, 05:09 pm »

A $575 power supply for a $699 computer?

Wayne1 · « **Reply #18 on:** 1 Jul 2010, 05:23 pm »

Why do you think the computer is only $699.00?

Something has to be cut back and in most cases it is in the power supply. It is not inexpensive to build a 6 amp linear power supply using quality materials, hand wired, point to point.

If you don't care about the best possible sound you can get out of this source, don't buy it. Simple as that.

Construct · « **Reply #19 on:** 1 Jul 2010, 06:28 pm »

Quote from: Wayne1 on 1 Jul 2010, 05:23 pm

If you don't care about the best possible sound you can get out of this source, don't buy it. Simple as that.

I would provide a lot of reasons for contesting/deconstructing that statement, but that would be as pointless as a ham sandwich at a bat-mitzvah.
I will attend to more important things like bringing the misses to see "Eclipse" so she can quit being the 3rd channel in my two channel system.