Why a linear power supply?

[nige2000]

My 12V rail powers 3 things at the moment

- picoPSU. This might just 'bypass' the 12V without generating noise but at least it's getting 12V clean. If I run the 2x2 12V directly to the board, maybe it makes a difference, maybe not. It whittles down the use of the picoPSU, although 12V, 5V and 3.3V are still supplied by the picoPSU through the 24 pin ATX socket.

- 12V into my precision regulator for my SSD. Okay not a separate rail but the very good DC regulator has fantastic noise rejection if indeed any noise is being polluted back into the 12V rail by the picoPSU/mobo

- the clock on my Juli@ card. This clock is a Fidelity Micro Clock 2 and has very good SPower D discrete on-board regulation as well.

 

So while it is just a single rail it is regulated by a "super regulator" and each component other than the picoPSU has it's own low noise DC regulation.

 

Just use a Texas Instruments TPS3510 to handle pc power supply supervision.

 

Sounds like a great system

Might be interesting to try dedicated rails I'd you got the parts lying about

Under clocking the cpu helps reduce noise too

Basically as low as fully functional

[JJJ]

I understand that it underclocks itself.

 

Re dedicated rails, I don't have the caps lying around. Plus the caps and regulators I am using are not cheap. I have bought the TPS3510 and a few other parts and would like to test that I fully understand its implementation before building out the other rails. Just a question of finding the time.

 

Plus a tri-rail bench power supply would make it easier...

[JJJ]

BTW I have a 160VA transformer which is complete overkill for this motherboard and processor. Even on boot up or playing streamed NTSC DVD ISOs upscaled to 1080p via JRiver's Red October it doesn't break 2.5A. Of course, if I wanted to add in a powerful video card (requiring a different mobo) to handle the very best MadVR now has to offer then I'd potentially need a lot more current capability.

 

How much current does each of your voltage rails consume?

[the_bat]

Are you an insurance adjuster?

 

No - I didn't realise you had to be. This board will be very quiet if we demand that people have professional qualifications before commenting on an issue.

 

I am not sure why you feel the need to warn others of insurance issues. .

 

The comment was in the context of Alex's post on why most people wouldn't be comfortable with DIY multi-PCB supplies - it's just one more reason why people might shy away.

 

As I understand it, most low production audio gear would give them cause to wonder, and all it would take is for the screws to be off the unit (even with the top still on) for them to fight you on a claim.

 

 

Which rather supports the point.

 

Alan

[kisjano]

i can use later class a 3.3v linear power there.example audio gd board.But the pico power maybee can not work,bcose shut down.my power dont do this,work fine with other psu.If you measure your motherboard atx socket,you see,just 1 rail 3.3v,1 rail 5v,1 rail 12v.

if you have more rail psu,...hehehe.So this one solution for the better sound.

[nige2000]

apologies for the late reply i couldnt remember the amperage of the top of my head

 

ok

bear in mind ive tried to minimize the current required

12v cpu @ 800mhz 0.6 a (ive seen up to 4 amp on boot up of sandybridge pcs at default bios settings)

12v mobo 24pin 0.15 a

5v 24 pin 1.0 a (one usb key installed, usb hdd's etc will put much load on this rail

3.3v 24 pin 0.6 a (ram underclocked so if default expect much more)

 

ssd's, usb keys usually pull about 0.15- 0.2 a each

 

 

i usually suggest that for haswell builds for those that are really really into it and understand the risks as its not that difficult to make a mistake and burnout a component (or burn down your house apparently ), those that are used to been in the wars will be ok

12v needs 3a capability

5v needs 2-3 a depending on the amount of usb devices plugged in

3.3v 2 a ive seen on various motherboards 3.3v requirements vary between brands and models

 

 

the pc at default bios settings doesnt really underclock itself, it fluctuates meaning the current demand is going up and down like a yo yo.

if you set parameters in the bios say 800 mhz cpu 800 ram it will help stabilize this

c states and eist etc are also a no no

[JJJ]

Interesting. I have the Haswell 4570T. I've only measured current off the 12V rail which powers everything. Less than 2.5A i.e. less than 25W. No graphics card, just the ESI Juli@ in the PCIe slot. Two SSDs, the picoPSU and Micro Clock 2 (current demand of the latter is tiny).

[nige2000]

Interesting. I have the Haswell 4570T. I've only measured current off the 12V rail which powers everything. Less than 2.5A i.e. less than 25W. No graphics card, just the ESI Juli@ in the PCIe slot. Two SSDs, the picoPSU and Micro Clock 2 (current demand of the latter is tiny).

 

if i remember correct with the pico 0.8 a to cpu and 0.8 a to everything else supplied by pico when underclocked

so thats 1.6 a total @ 12v when underclocked

bear in mind motherboards vary a little

[JJJ]

yes consistent with my experience. A little blip on boot not exceeding 2.5A, about 0.8A idle and about 1.5A processing multichannel LPCM to HDMI. Circa 2.2A upscaling via via JRiver Red October. But even 2.5A 12V into picoPSU is 30W which if all was being drawn as 5V from the other side of the picoPSU is 6A and hence my questions asking for individual rail voltages from those who have implemented these.

[nige2000]

You have me confused

The 5 v rail requirement would never reach 6 a, maybe 3 a if you had lots of hdd's usb devices etc

 

I tend to only have one usb hdd so 1.5 a is my constant Requirement

 

If under clocking is implemented the boot surge of current demand is prevented alough a slightly slower boot time

 

Are you using this pc for movie hires playback?

[JJJ]

Power (W) = voltage x current

 

All I am saying is that if a picoPSU peaked at 2.5A 12V input and was feeding ALL (an assumption) this only as 5V (o current draw as 12V and 3.3V) then that's 6A of 5V I know there will be some draw as 12V and 3.3V but it is impossible for me to determine (absent monitoring the output side of the picoPSU) how much is being drawn as 12V, 5V or 3.3V.

 

I only run SSDs.

 

I may have my IT guy look at under clocking but so far I haven't seen the need to - especially considering the below:

 

At the moment I use this mostly for audio (high res stereo and multichannel). Occasionally I tap my old DVD collection which I have ripped (c360 movies). Maybe one day I will want to use MadVR's best settings which would require a very powerful GPU, new mobo etc but not for now.

[kisjano]

pc power

[Liam]

See my review of the Keces DC-116 Linear Supply post #111

 

http://www.computeraudiophile.com/f8-general-forum/keces-dc-116-linear-power-supply-unit-quick-review-17623/index5.html#post332436

[hytechrednek]

I got an unexpected treat today. I've been building a linear power supply from scratch and wanted to get a cable that would plug into my 2009 Mac Mini. At first I planned to cut the cable from my stock power supply and use it, but decided I might keep it intact and find a mac mini power supply on eBay that was broken and just salvage the cord and connector from it. I had to settle for one of the earlier model power supplies that produces only 85 watts. The one that came with my Mini is 110 watt. Still my intention was only to salvage the cord / connector from it and my total cost for the 85 watt unit was only $5.50 which included the shipping.

 

When I got it today, I was about to cut the cable / connector off and throw the rest away, but decided to see if it actually worked with the Mac Mini. Not only does it work, but it sounds WAY BETTER than the 110 watt unit I have. It even puts to shame the home brew power supply I made! It sounds much sweeter than the other two. It really cleans up the upper frequencies. While there is more meat on the bones of the linear supply I put together, the 85 watt has a huge edge on the other two from a musical enjoyment standpoint.

 

Has anyone ever noticed this difference in the stock Apple power supplies, or do I just a a freak of nature here in this particular 85 watt supply?

[sandyk]

Perhaps this PSU has less hours on it's main electrolytic storage capacitors than the PSU in your 5 year old Mac Mini ?

[hytechrednek]

Perhaps this PSU has less hours on it's main electrolytic storage capacitors than the PSU in your 5 year old Mac Mini ?

 

I suppose it could be possible the caps are bad in the 110 watt unit, but I just auditioned this evening one additional 110 watt unit that I borrowed from a friend. It has a similar sound character to my 110 watt P/S. I suppose both of them could be having cap problems but the likelihood is getting less with two samples.

 

I had a 2006 mac mini that I sold not long ago with a 110 watt supply and it too was unremarkable in sound quality. Very similar to what I hear with the 2009 mini using the 110 watt P/S. I heard a 2010 mini with a Mojo / Core Audio P/S and was very impressed. Hence the reason I was experimenting with a DIY.

 

The 85 watt unit looks used like it has been around awhile. According to Apple they were last built in 2005. From 2006 onward they provided 110 watt units. So at the very least the 85 watt has more age than the 110 watt units, but perhaps less usage. I could ask the person I bought it from what kind of usage it has seen.

 

There is such a striking sound difference in the 85 watt compared to what I'm accustomed to hearing with the Mac Mini, I have to suspect there is something else going on. I may buy another just to confirm this is not a fluke.

 

I would also note that the 85 watt does not seem to be having trouble powering the Mini. It is slightly warm to the touch. The case is measuring 101.9F. I suspect a SSD would reduce the load on it significantly.

 

Thanks for your thoughts.

[sandyk]

A well designed Linear PSU should outperform the existing SMPS PSUs. Have you checked out the posts by Alex C and John Swenson about their soon to be released linear PSU for Mac Minis ?

 

Regards

Alex

[Superdad]

A well designed Linear PSU should outperform the existing SMPS PSUs. Have you checked out the posts by Alex C and John Swenson about their soon to be released linear PSU for Mac Minis ?

 

Regards

Alex

 

I might get in trouble with the management, but as means of correcting you, I can post that the JS-2 began shipping last week.

[kisjano]

Asrock z97e itx,i7 4770k,win server 2008(no 2012!!)2 pcs external pci e board,separated the video process and power.Dell 12v 18A Smps power:cpu,fan,ssd,vga card.Linear powered itx 12v power supply with 80000uf nover cap.Separated rail 3.3v r core(80000uf nover) with the pcie usb card.

[baddog]

Alex - again not to stray off topic - but I did want to say those power supplies look wonderful! Congratulations.

[Superdad]

Alex - again not to stray off topic - but I did want to say those power supplies look wonderful! Congratulations.

 

Thanks very much. The R-core in them really makes so magic. Not only was the difference between a good toroid and the R-core obvious in the bass with a computer, but when powering a DAC the difference was top to bottom. I really hope that people will use our supply for things other than just the computer and peripherals.

I'd best pipe down again...

[kisjano]

Test phase 3.3v motherboard bus power with 2pcs switch.After the booting separate linear power on,then public power(3.3) switch off!!Sound amazing!!!!!Alredy have 2 rail,2pcs r core10w transformers:one external pcie usb card 3.3v,other this new rail,more lin.rail for the atx power,And smps power:cpu,ssd,fan,external vga card.

[hnac]

Maybe a bit off topic, but did you turn off hyperthreading and CPU frequency scaling features such as EIST (through the BIOS) or other powersaving features? It made a huge difference in my setup.

[pre]

I might get in trouble with the management, but as means of correcting you, I can post that the JS-2 began shipping last week.

 

[ATTACH=CONFIG]13472[/ATTACH]

 

Very impressive case and seems to have selectable output voltages, but any idea why 19V is not an available option for even more universal flexibility ?

[tboooe]

Very impressive case and seems to have selectable output voltages, but any idea why 19V is not an available option for even more universal flexibility ?

Agreed, if 19V was available I would purchase one right now for my current music pc and when I upgrade my CAPS I could use the 12V option.