ATTENTION Current Mac mini/A+ users: Boot Mavericks from an SD card, load a RAMdisk, dismount your internal SATA drives, and pour a drink for the musicians walking out of your speakers!

[BobL]

I don't think that is correct Bob. The fans respond the same either way.

The minimum fan speed is dictated by the computer/OS. My 2012 can go down to 1800rpm with or without the MMK installed. And the 2011 I had could only go down to 2300 regardless. I don't know if it is the year or the fact that the 2011 I worked on had 2 hard drives installed.

Thanks Alex,

 

Just because I had never seen a Mini fan at anything other than 1800rpm on minimum, I made the elementary error of assuming they were all this way. A lesson to me not to generalise from the particular; something I used to tell students!

 

pl_svn, I too have never seen my fan speed move off minimum in normal operation. When I first put the MMK in I wasn't sure it was working properly, until I deliberately forced up the speed with Macs Fan Control. It actually responds very rapidly when it needs to!

[JohnSwenson]

Hi Alex!

 

Interesting. Do you know what speed it ran at when it was under pulse control?

 

One thought, perhaps for JS to answer: given that fans respond differently to the same dc voltage, might this mean that the MMK needs to have a lower minimum voltage output to cope with superspeed fans like this one?

Cheers

 

Bob

 

It shouldn't matter, the fan is in a feedback loop, the motherboard sends out a PWM ratio, the tachometer on the fan sends back the actual speed, if the spped doesn't match what the motherboard wants it changes the PWM ratio until it does match. Thus individual variations in voltage->speed from fan to fan will be taken care of by the feedback loop.

 

There are really only two issues to deal with, does the minimum speed of the fan differ when under PWM VS DC voltage and getting the PWM to voltage range right so that all usable speeds of the fan can be controlled.

 

I did extensive testing of the fan Alex gave me and found the minimum fan speed was identical with DC voltage control or PWM. What seems to happen is if the DC voltage is very low nothing happens at first, then after a couple seconds it "kicks" in fast then slows down to a very slow speed. The only way I can see this happening is if the fan includes a voltage doubler circuit to "kick start" it when fed a low voltage. Or some unusual arrangement of coils to do the same thing. However it is done it actually works.

 

I designed the PWM to voltage circuit to be a linear PWM ratio from 0 to 12V. (actually slightly less than 12V, the amp I'm using can't quite do rail to rail, but close). Because of the feedback loop that is all that is necessary, any non-linearities of the voltage to speed curve are automatically taken care of by the feedback.

 

John S.

[BobL]

It shouldn't matter, the fan is in a feedback loop, the motherboard sends out a PWM ratio, the tachometer on the fan sends back the actual speed, if the spped doesn't match what the motherboard wants it changes the PWM ratio until it does match. Thus individual variations in voltage->speed from fan to fan will be taken care of by the feedback loop.

 

There are really only two issues to deal with, does the minimum speed of the fan differ when under PWM VS DC voltage and getting the PWM to voltage range right so that all usable speeds of the fan can be controlled.

 

I did extensive testing of the fan Alex gave me and found the minimum fan speed was identical with DC voltage control or PWM. What seems to happen is if the DC voltage is very low nothing happens at first, then after a couple seconds it "kicks" in fast then slows down to a very slow speed. The only way I can see this happening is if the fan includes a voltage doubler circuit to "kick start" it when fed a low voltage. Or some unusual arrangement of coils to do the same thing. However it is done it actually works.

 

I designed the PWM to voltage circuit to be a linear PWM ratio from 0 to 12V. (actually slightly less than 12V, the amp I'm using can't quite do rail to rail, but close). Because of the feedback loop that is all that is necessary, any non-linearities of the voltage to speed curve are automatically taken care of by the feedback.

 

John S.

 

Thanks John,

 

I guess that wraps it up pretty well.

 

Bob

[Superdad]

Thanks John,

 

I guess that wraps it up pretty well.

 

Bob

 

Yeah, I love when John writes this stuff. He explained exactly all that to me on the phone many months ago during development, but I am not that good at note-taking and writing is always more organized than speaking. So whenever he posts clear explanations like the above, they get pasted right into my "white-paper"/FAQ file for when I finally get a real web site up. Thanks again John.

[AnotherSpin]

Small update to discussion of Alex's idea (copied from HQPlayer thread):

 

"Well... sometimes the simplest idea never comes first. I experimented a lot with SD cards previously, however, every time I was formatting a card to make it bootable with OS installed on a card (stripped or full) and launched HQPlayer from app folder. Now I even do not remember if I ever tried to run system from internal ssd, and HQPlayer from SD card. After 1markr post I decided to try this as well. Formatted one of my bootable SD (Sandisk) into regular external disk, downloaded latest version of HQPlayer, and copied on SD. Booted mac mini from ssd and opened HQPlayer from inserted SD. I am not smoking, but the sound is startlingly realistic and alive. Whether green regen shines in this setting even more, or some other things are in effect, but I listen my music with a greatest joy. So, my advice to all SD aficionados would be to give it a try, it is so simple and easy. Thank you, 1markr!

 

Update: Info for those who will want to try HQPlayer from SD card - when I previously tried OS on bootable SD card, I found out that I prefer 16GB Transcend regular card over 32GB Sandisk fast card. Now, when OS on ssd and HQPlayer on SD card, it seems I prefer the sound of HQP from 32 GB Sandisk rather than from 16GB Transcend. I also did clean install of Yosemite from USB drive."

[Superdad]

Deleted.

[mrvco]

Has anyone tried a UHS-ii SDXC card w/ the Mac Mini yet? They aren't exactly cheap, but they should provide a pretty substantial speed increase over the UHS-i 90/95 MB/s cards.

 

Lexar Pro 2000x UHS-II/U3

 

SanDisk Extreme Pro

[Superdad]

Has anyone tried a UHS-ii SDXC card w/ the Mac Mini yet? They aren't exactly cheap, but they should provide a pretty substantial speed increase over the UHS-i 90/95 MB/s cards.

 

Well there is not much point to those faster cards with the Mac mini SDXC slot. It is limited to 2.5GT/sec which after translating and accounting for PCIe overhead comes out to about 32MBytes/sec., so those expensive UHS-II cards are lost on the mini.

 

I do have a nice Toshiba Exceria still sealed on my desk that I have been meaning to try. The better cards may prove worthwhile for other reasons (we certainly know that some of the cheap junk cards are not very reliable).

 

Cheers,

ALEX C.

[mrvco]

Well there is not much point to those faster cards with the Mac mini SDXC slot. It is limited to 2.5GT/sec which after translating and accounting for PCIe overhead comes out to about 32MBytes/sec., so those expensive UHS-II cards are lost on the mini.

 

I do have a nice Toshiba Exceria still sealed on my desk that I have been meaning to try. The better cards may prove worthwhile for other reasons (we certainly know that some of the cheap junk cards are not very reliable).

 

Cheers,

ALEX C.

 

Ah thanks. After a bit of searching I was led to believe that 2.5 GT/sec was equivalent to 250 MB/s (after overhead). Is that just the theoretical bandwidth? Or someone's incorrect interpretation of GT/sec?

 

And is Sandisk still the card of choice?

[wwaldmanfan]

Has anyone tried a UHS-ii SDXC card w/ the Mac Mini yet? They aren't exactly cheap, but they should provide a pretty substantial speed increase over the UHS-i 90/95 MB/s cards.

 

Lexar Pro 2000x UHS-II/U3

 

SanDisk Extreme Pro

 

I have three SD cards: a 32MB 95MB/S Sandisk ExtremePro SDHC, a 16GB 48MB/S Sandisk Ultra PLUS SDHC, and a 64GB 30 MB/S SanDisk Ultra SDXC. I use them primarily to swap music files between my desktop work Mac and my MacBook Pro dedicated music server. I have written to, read, erased and reformatted these cards repeatedly. It now seems that the read/write speed of the cards has decreased. I saw somewhere this can happen with SSD's as well, that you should avoid excessively writing to them, reformatting, or defragmenting them.

 

I would advise, for best performance, that if you are going to use a SDXC or SDHC card as a boot disk, that you start with a new card, clone your computer drive to it, and refrain from reusing it for anything else.

 

Because of this, I have gone back to using my MBP's internal 120GB SSD drive, (formatted with two non-journaled 60GB partitions--Mavericks and Yosemite). The computer boots in 12 seconds from startup chime to fully revealed desktop, including mounting external FireWire volumes and automatically launching Audirvana as a startup app. I then eject the second boot partition and just run it that way.

 

I don't really hear any significant difference when booting via the SATA III SSD vs. a SD card anyway, as per Superdad's recommendation. As I always say, perhaps my system or my ears are not resolving enough.

[Superdad]

Ah thanks. After a bit of searching I was led to believe that 2.5 GT/sec was equivalent to 250 MB/s (after overhead). Is that just the theoretical bandwidth? Or someone's incorrect interpretation of GT/sec?

 

You are right. Actually, 2.5 GT/sec converts to 3.125 Gbps (under PCI 2.0 overhead) which translates to about 390 MB/sec. Though I do doubt one could get near that throughput on a Mac mini SDXC slot. Plus the UHS-I and UHS-II high speed modes require use of the 4-bit mode, which may not be desirable for our application. I really don't know.

[Pascal64]

Hey guys, i did this trick and just want to say : THANK YOU

 

Mavericks on Transcend SD card pull SQ of my Mac Mini in a next level.

 

Happy new year to all.

[BobL]

Hey guys, i did this trick and just want to say : THANK YOU

 

Mavericks on Transcend SD card pull SQ of my Mac Mini in a next level.

 

Happy new year to all.

Moi aussi, on both counts, if a bit late for the second one! I can't be certain that this is the best improvement Alex and John have made to my system, because they are all so interconnected. Without the Regens, I might not be able to hear how good this one is, etc., etc.

 

A elated query, to Alex and anybody else with information:

 

A while back, when the 2014 Mini appeared, you suggested that the PCIe card version could be used in place of the SDHD card. Has anybody done this? I accepted the idea at the time, but thinking it over, I'm not sure what goes where, OS or music files?

[Superdad]

Moi aussi, on both counts, if a bit late for the second one! I can't be certain that this is the best improvement Alex and John have made to my system, because they are all so interconnected. Without the Regens, I might not be able to hear how good this one is, etc., etc.

 

A elated query, to Alex and anybody else with information:

 

A while back, when the 2014 Mini appeared, you suggested that the PCIe card version could be used in place of the SDHD card. Has anybody done this? I accepted the idea at the time, but thinking it over, I'm not sure what goes where, OS or music files?

 

Hi Bob:

 

Well despite the lack of a quad-core i7 model, I think the 2014 Mac minis are terrific. I have installed a lot of our Mac mini DC-conversion/Linear Fan Controller Kits (MMK) in 2014 units (its a complimentary service I offer to JS-2 buyers), and the 2014 model is MUCH easier to work on than the 2010-2012 units.

 

And I have been advocating that people get them with just the PCIe Flash Drive and not the HD or Fusion drive so as not to have any SATA bus drive active. In theory the PCIe Flash drive--being directly connected to the PCIe bus controller--should sound as good as the SD card, just monstrously faster. Though just like the RAM in a computer, there is a LOT of high-speed switching going on and the PCIe Flash Drive could have greater emissions.

 

Truth be told, although I've had a lot of them through here, I have not had a chance to compare a 2014 w/PCIe Flash to my 2012 SD-card booted machine, so I can not claim they are equal sonically or that one is better. To do it fairly, I would have to partition the PCIe drive, install and then slim an OS. But I've been so busy this last year that my SD card is still just my 70 processes/290 threads Marvericks install. So additionally I'd need to make an SD card with El Capitan (and slim that too).

 

Based on what I hear when I dismount all my internal SATA drive partitions (I'd yank the drive but sometimes I use its partitions for experiments), I do think that avoiding the SATA bus is very much a part of what makes the SD card trick work so well for SQ. So the PCIe Flash should sound very good.

 

To address your question about using the Flash drive just for the OS and apps or to also use it for music:

Well I find that tracks played from the SD card (I keep a few there) are second in SQ only to playing them from the gold-standard of RAM disk. So a PCIe Flash drive that could hold a lot of one's music library would be great (Apple offers them up to 1TB now).

 

Short of storing/playing tracks from the PCIe drive, one then has to carefully consider what external interface/storage to use, since it is always the activity/processes of the interfaces running on the DAC-connected computer which matter to SQ.

Of course I wrote about that at length in reports that came immediately before and after this thread (will provide the links here for those just joining as those threads were a long time ago:

http://www.computeraudiophile.com/f27-uptone-audio-sponsored/my-deep-dive-media-storage-interfaces-musical-differences-heard-between-chipsets-firewire-400-800-universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-sata-flash-drives-sd-cards-and-network-shares-warning-may-cause-seizures-dbt-crowd-and-flat-earth-naysayers-18108/

 

http://www.computeraudiophile.com/f27-uptone-audio-sponsored/uh-oh-i-beat-my-sd-card-trick%3B-bypass-your-ethernet-switch-and-make-your-external-drives-sound-close-ram-disk-using-apple-thunderbolt-ethernet-adaptor-and-second-network-connection-18475/

 

In a nutshell:

Network shared storage and a BlueJeans/Belden Cat6a cable is my recommendation for full music library storage and playback. Thus an optimal 2014 Mac mini would have just a PCIe Flash drive and the only attached cables would be a DC cable for power (got to ditch the SMPS and PWM fan pulses!), the USB cable to the DAC, and an Ethernet cable (bypass the EN switch or use a fiber optical LAN isolator).

 

Just my $0.02

 

Best,

--Alex C.

[wwaldmanfan]

And I have been advocating that people get them with just the PCIe Flash Drive and not the HD or Fusion drive so as not to have any SATA bus drive active.

--Alex C.

 

Alex,

When booting from an optimized SD card, is it sonically advantageous to simply eject the internal SSD SATA III volume(s) from the desktop, or must one physically disconnect them somehow?

Thankx, Mike

[Superdad]

Alex,

When booting from an optimized SD card, is it sonically advantageous to simply eject the internal SSD SATA III volume(s) from the desktop, or must one physically disconnect them somehow?

Thankx, Mike

 

If you "eject" all the partitions it does seem to effectively turn off the SATA interface--or at least the associated activity/processes. Enough for me to hear a difference. But at some point--the next time I am inside my machine--I'll just yank the drive entirely.

[Pascal64]

Hi Alex and Others.

 

Did you speak about RAM disk ?

 

I've just find much better than the SD card trick !!

How is it possible ?

It's called TinySqueeze.

Dimas from From Russia did this program to put the mini OS on RAM.

 

Guess what ?

It's sooOOooo gooOOd

Next level.

 

I talk how to instal it on the mac Mini here on a french forum

Optimisations pour Mac (mini) Audiophile - Enceintes et Musiques

 

regards,

Pascal

[Superdad]

Hi Alex and Others.

 

Did you speak about RAM disk ?

 

I've just find much better than the SD card trick !!

How is it possible ?

It's called TinySqueeze.

Dimas from From Russia did this program to put the mini OS on RAM.

 

Guess what ?

It's sooOOooo gooOOd

Next level.

 

I talk how to instal it on the mac Mini here on a french forum

Optimisations pour Mac (mini) Audiophile - Enceintes et Musiques

 

regards,

Pascal

 

Hi Pascal:

 

Well of course I and many others have played music tracks from RAM disk and/or launched our preferred player apps from RAM disk, and indeed it is the "gold standard" for playback location--but feather inconvenient for music storage.

 

And I have read about PeterSt's script and drives for loading Windows OS onto RAN disk and then dismounting/disconnecting the HD.

And I have wished for something to allow me to that for OS X.

 

Now you come to us with that solution?! Fantastic! But you give me a link to the 48-page thread you started, and it all in French and I can't find or read the instructions for putting OS X in RAM.

 

Please help us with more specifics on how to do this.

 

Excitedly yours ,

 

--Alex C.

[Yucca06]

It's a stripped linux OS, and you can boot from it on a USB stick. So it's also doable with a Mini...

 

(didn't try this one)

[Pascal64]

Sorry, wrong link :

Mac Tiny - Enceintes et Musiques

 

i can translate, but later.

[Pascal64]

Ok Guys,

 

i try to explain but my english is poor.

 

1) you have to make a boot USB key with windows

-format fat 32

-cheap, 8 go max

-use this to make it

https://sourceforge.net/projects/core2usb/

http://tinycorelinux.net/6.x/x86/release/Core-current.iso

https://bitbucket.org/dimas_sky/tinysqueeze/downloads/tinysq_1.3.zip'>https://bitbucket.org/dimas_sky/tinysqueeze/downloads/tinysq_1.3.zip

 

With core2usb, You install core current iso on usb key

BUT : the drive must be empty and windows create a "system volume information" you have to delete before !

if d is your drive

C:\>D:

D:\>attrib -s -h /S /D

D:\>attrib -r /S /D

D:\>rd "System Volume Information" /S

System Volume Information, Etes-vous sûr (O/N)? O

Go fast before windows recreate it and unzip Tinysqueeze direct on the USB key

It's done But did not work on mac mini.

You should go on Dimas home page to catch "Broadcom kernel"

https://bitbucket.org/dimas_sky/tinysqueeze/downloads

 

unzip those files and replace it in the same directory.

Most of the work is done.

 

Put that USB on the mac mini with screen and keyboard and boot on it

Some strange color things later, Tiny is mounted on computer RAM.

 

You have to find The IP address.

 

type :

tc

soundex.ru

>welcome to Tinysqeeze

ifconfig -a help you to find it.

 

Type that address on Safari.

You con now configure Tiny

 

see thread#2 here : Mac Tiny - Enceintes et Musiques

 

Type now on LMS (green icon), change language and play music.

For any questions you can go on french forum (haha, it's your turn)

TinySqueeze - Enceintes et Musiques

 

And if you like, do not forget to give some tips to Mr Dimas via paypal at [email protected]

 

Enjoy

Pascal

[Pascal64]

Nobody try ?

Come on guys…. (or not because) it's - a only one way ticket, after that, no return is possible.

 

Dimas (very busy guy this days) make a special kernel for mac mini :

https://bitbucket.org/dimas_sky/tinysqueeze/downloads

 

1) make your USB key

2) change the files with that one

[Superdad]

Nobody try ?

Come on guys…. (or not because) it's - a only one way ticket, after that, no return is possible.

 

Thank you for sharing that PAscal. But it is not what I was hoping for. I am not terribly interested in running LMS to a Squeezeplayer on my Macs. If I can't run HQ Player then I'm not interested.

 

I do have a USB stick that boots a very minimal text-nly Linux and loads the HQ Player NAA. But as optimized as my mini is, the advantage of NAA really does not deliver results for me and is inconvenient (at least until I buy a Sonore microRendu).

 

Best regards,

 

--Alex C.

[Le Concombre Masqué]

I share your opinion on NAA. I even dared claiming (and did not get any echo) on the HQP thread that most if not all of the NAA sound signature could be obtained while operating desktop and NAA on one single machine (wifi), negating the whole theory (I''m still feeding my green Regen via a Corning). It will be mighty interesting to read you feedback on the Sonore !

Thank you for sharing that PAscal. But it is not what I was hoping for. I am not terribly interested in running LMS to a Squeezeplayer on my Macs. If I can't run HQ Player then I'm not interested.

 

I do have a USB stick that boots a very minimal text-nly Linux and loads the HQ Player NAA. But as optimized as my mini is, the advantage of NAA really does not deliver results for me and is inconvenient (at least until I buy a Sonore microRendu).

 

Best regards,

 

--Alex C.

[Pascal64]

I agree : LMS is not my cup of tea.

but here, with minimalist OS and LMS on RAM, The SQ is perfect.

background noise disepear.

My Uptoned Mac Mini never sound like this.

 

some friends of me runs Tinysqueeze with dual PC (server-player) + SOTM superclok USB card. (No REGEN nedeed)

it's sounds a little better but i love my Mac mini !

 

 

I dont Know about HQ player.

Before Tinysqueeze i was with Audirvana and SD card + CAD scripts (SSD unmouted)

best regards from France,

Pascal