pico power?

do pico power supplies negate the beneficial effects of a linear PSU input?

e.g. HDPlex 400 LPSU has a ripple/noise of 2 millivolts, but if that relatively clean power is then passed to a switching pico ATX 24 pin PC mobo connector with a ripple of 70 millivolts, has the improvement been lost at the final hurdal? Will the mobo 'read' 2 or 70 millivolts of noise?

http://jplay.eu/forum/index.php?/topic/1979-rebuild-and-improved-power-supply-for-a-singlepc/?p=34872

11 hours ago, Tomslin said:

http://jplay.eu/forum/index.php?/topic/1979-rebuild-and-improved-power-supply-for-a-singlepc/?p=34872

OK - many thanks!

On 7/27/2018 at 1:06 PM, Tomslin said:

http://jplay.eu/forum/index.php?/topic/1979-rebuild-and-improved-power-supply-for-a-singlepc/?p=34872

"I tested with two transformer, one with 24V 250VA and second one 24V 75VA."

What are these transformers e.g. linear/switched? connected to mains?

So, switched is noisiest - yes?

The battery is cleanest I.Y.O.?

the LPSU is in the middle somewhere?   ...closest to the battery or switched supply?

The PICO's perfomance is influenced by the supply (switched/linear/battery)?

How does 'a straight' LPSU compare to one with a PICO on the end of it, when connected to a mobo? Ripple/noise?

Many Thanks!

15 hours ago, the_doc735 said:

"I tested with two transformer, one with 24V 250VA and second one 24V 75VA."

 

What are these transformers e.g. linear/switched? connected to mains?

 

The answer is in my post (which I linked to): "I use voltage regulator based on LT1083 for both 12V and 20V for 16-24V version of Pico".

And these regulator board I use was these:

http://i1286.photobucket.com/albums/a604/kuty78yu8/Pico%20test/DSCN2624_zpsebp7wtab.jpg~original

This is the same as feed a pico with eg such one:

http://www.teradak.com/products/98.html

15 hours ago, the_doc735 said:

How does 'a straight' LPSU compare to one with a PICO on the end of it, when connected to a mobo? Ripple/noise?

 

I suppose you mean full rail/multirail when you say "straight". Pico is not a sensible option if you are looking for the best possible SQ. That's also the reason I did that test more than two years ago. If you read earlier in the thread, there were three manufacturers who claimed the opposite: "I had a small discussion/email Exchange with Paul Pang couple of months back and he thinks that if the linear psu (non-atx) has a good a/c transformer and regulator, their is no need for going linear atx route and a pico will just work fine. Incidentally, two other well known psu Company (Uptone & Mojo audio) Believes the same".

But as said, posts is quite old. And now I have made some new discoveries. But when we talk about comparing Pico with multirail LPS, so it's still up to date. I repeat: Pico has nothing to do in a pure and good Audio PC, in my opinion.

Best regards

Tomas

3 hours ago, Tomslin said:

The answer is in my post (which I linked to): "I use voltage regulator based on LT1083 for both 12V and 20V for 16-24V version of Pico".

 

And these regulator board I use was these:

http://i1286.photobucket.com/albums/a604/kuty78yu8/Pico%20test/DSCN2624_zpsebp7wtab.jpg~original

This is the same as feed a pico with eg such one:

http://www.teradak.com/products/98.html

 

I suppose you mean full rail/multirail when you say "straight". Pico is not a sensible option if you are looking for the best possible SQ. That's also the reason I did that test more than two years ago. If you read earlier in the thread, there were three manufacturers who claimed the opposite: "I had a small discussion/email Exchange with Paul Pang couple of months back and he thinks that if the linear psu (non-atx) has a good a/c transformer and regulator, their is no need for going linear atx route and a pico will just work fine. Incidentally, two other well known psu Company (Uptone & Mojo audio) Believes the same".

 

But as said, posts is quite old. And now I have made some new discoveries. But when we talk about comparing Pico with multirail LPS, so it's still up to date. I repeat: Pico has nothing to do in a pure and good Audio PC, in my opinion.

 

Best regards

Tomas

Thank you very much for your time & trouble, I do appreciate your detailed reply. Someone (who had a vested interest) had convinced me to go with the PICO route coupled with a single 12-24V LPSU output. After this (what you have written), I'll have to think again! Doesn't seem to be that many ATX LPSU's though?

Thank you for your trust!

Can you say more exactly what it was that convinced you to go the Pico route? It would be interesting to know.

Yes, you are right. Not many ATX LPS on the market, and I Think it's strange. Actually I only knew two: HD-Plex and Teradak. In addition to these entire map of possibilities for DIY with the help of Ebay or AliExpress, for example.

19 minutes ago, Tomslin said:

Thank you for your trust!

 

Can you say more exactly what it was that convinced you to go the Pico route? It would be interesting to know.

 

Yes, you are right. Not many ATX LPS on the market, and I Think it's strange. Actually I only knew two: HD-Plex and Teradak. In addition to these entire map of possibilities for DIY with the help of Ebay or AliExpress, for example.

 

Out of the many threads and emails I've read fairly recently someone with a vested interest suggested that the switching PICO is virtually transparent and adds virtually nothing to noise when powered by a single rail/single output of 12-24 volts LPSU with only 0.02 millivolt mV ripple. Also other sellers of PICO devices have hinted at the same kind of performance figures. Then after a while you actually begin to start to believe it!

DIY! - Ummm? I wouldn't be able to build a DIY LPSU, not enough knowledge.

Cheers!

Thanks for the explanation, it's about the same statements I also heard before and that I also believed in. (Yes, I have used Pico during some years too). Although it may be true in theory (can't contradict it) it's not true in practice. Perhaps also a good example when one not shall pay too much attention to measured values, instead to just listen. I don't either believe the biggest problem with Pico is noise, instead it creates jitter from high frequency impact on other parts. This is confirmed by the fact that I received approximately the same (bad) result when Pico was fed by battery (=0V ripple) as when it was fed with a LPS.

9 minutes ago, Tomslin said:

Thanks for the explanation, it's about the same statements I also heard before and that I also believed in. (Yes, I have used Pico during some years too). Although it may be true in theory (can't contradict it) it's not true in practice. Perhaps also a good example when one not shall pay too much attention to measured values, instead to just listen. I don't either believe the biggest problem with Pico is noise, instead it creates jitter from high frequency impact on other parts. This is confirmed by the fact that I received approximately the same (bad) result when Pico was fed by battery (=0V ripple) as when it was fed with a LPS.

"Pico instead it creates jitter from high frequency impact on other parts." Maybe that's were the DIY comes in? e.g. a jitter reducing component after the PICO, but before the mobo (with a 24 pin extension cable). i.e. put the jitter component in the extension cable (in line)?

I've used picoPSU to power a fanless Celeron board. I've supplied the pico with a cheap LPS -- the "ultra el-cheapo". Sounds great.

1 hour ago, jabbr said:

I've used picoPSU to power a fanless Celeron board. I've supplied the pico with a cheap LPS -- the "ultra el-cheapo". Sounds great.

What?   ...are U joking?   ?

...can U possibly say which LPS this is please?

1 hour ago, jabbr said:

Ebay has various linear psus under "ultra low noise linear power supply" -- I look for the ones with r-core transformers but look around for what you need.

Ummm? Well, these seem to be all chinese? prices are good, most lack long descriptions, some even lack the basics! One or two are more detailed. Saying "ultra-low" is one thing, but none of them give ripple/noise/broadband impedance i.e. NO FIGURES!

But you say they are good and your system sounds great?

Is it the case that if they had the name "dCS" on them with really fancy advertising/description, they would cost thousands?

Prices are LOW due to cheap labour? (& "no name" goods)....

Can these really be as good as Paul Hynes etc!

1 minute ago, the_doc735 said:

Can these really be as good as Paul Hynes etc!

As good for what? To power a pico? Sure!

I build my own supplies. I own and still use one of the “ultra el-cheapos”

2 hours ago, jabbr said:

As good for what? To power a pico? Sure!

 

I build my own supplies. I own and still use one of the “ultra el-cheapos”

Everytime I find someone on forums that "build there own" and ask them to build me something, there is always a reason why they can no longer do that! Can you build me an ATX linear PSU?

As good as a Paul Hynes test figures (if there are any?)

don't know if anyone as ever bothered to compare the likes of Paul Hynes to the chinese “ultra el-cheapos”?

Something like this: https://www.ebay.co.uk/itm/Finished-100VA-Ultra-Low-Noise-linear-Power-supply-ouptut-9v-12v-19v-24v-etc/221884083511?hash=item33a9526d37%3Ag%3At8cAAOSwuTxV9QXt&LH_PrefLoc=2&_sop=15&_sacat=0&_nkw=ultra+low+noise+linear+power+supply+r-core&_from=R40&rt=nc&LH_TitleDesc=1

you think these are good?

Many thanks!

Much better than Pico

https://www.hdplex.com/hdplex-400w-hi-fi-dc-atx-power-supply-16v-24v-wide-range-voltage-input.html

18 minutes ago, TubeMan said:

Much better than Pico

 

https://www.hdplex.com/hdplex-400w-hi-fi-dc-atx-power-supply-16v-24v-wide-range-voltage-input.html

Please explain your reasons for declaring the hdplex to be 'better' than a pico?

Many Thanks!

better components,
better design,
better sound,

High Voltage Endurance SANYO and Fujitsu Solid State Capacitors

16V-24V wide range voltage input support, 6 layer 2oz copper PCB

Germany Würth Elektronik High Current Inductance, Smooth Response Curve for Peak Load

Infineon MOSFET, TI Control Chip, WIMA Audio Grade Capacitor

18 minutes ago, Superdad said:

Look at the cable harness pictured with the PicoPSU (http://www.mini-box.com/picoPSU-160-XT) and you will see that the 12V input (from external LPS of course) is passed through to the motherboard (on the 20/24 pin connector and on the  CPU 4-pin) completely unadulterated.

 

What many of our (JS-2) clients do is install another DC-barrel jack at the back panel of their PC and have it run directly to the main critical 5V device—the SATA drive.

 

All motherboards are loaded with DC-DC switching regulators anyway (most of the chips run off 1.1V or 3.3V), so the couple of extra DC-DC converters on a PicoPSU module are quite benign. Such switching regs are unavoidable—and they are not to be equated with a switch-mode power supply (whose primary evil is anyway not noise but rather high AC leakage).

intriguing!- very good information, thank you, well worth some consideration!

My SSD's are M.2 NVMe, not SATA.

Cheers!

28 minutes ago, Superdad said:

 

It is a fine product. And yet it takes 19V input and converts that to 12V (and other voltages) using, guess what: DC-DC switching regulators. 

exactly!...

..."BUT!" ~ input is "16V-24V wide range voltage input support", where do you get the 19V from?

16 hours ago, Tomslin said:

The answer is in my post (which I linked to): "I use voltage regulator based on LT1083 for both 12V and 20V for 16-24V version of Pico".

 

And these regulator board I use was these:

http://i1286.photobucket.com/albums/a604/kuty78yu8/Pico%20test/DSCN2624_zpsebp7wtab.jpg~original

This is the same as feed a pico with eg such one:

http://www.teradak.com/products/98.html

 

I suppose you mean full rail/multirail when you say "straight". Pico is not a sensible option if you are looking for the best possible SQ. That's also the reason I did that test more than two years ago. If you read earlier in the thread, there were three manufacturers who claimed the opposite: "I had a small discussion/email Exchange with Paul Pang couple of months back and he thinks that if the linear psu (non-atx) has a good a/c transformer and regulator, their is no need for going linear atx route and a pico will just work fine. Incidentally, two other well known psu Company (Uptone & Mojo audio) Believes the same".

 

But as said, posts is quite old. And now I have made some new discoveries. But when we talk about comparing Pico with multirail LPS, so it's still up to date. I repeat: Pico has nothing to do in a pure and good Audio PC, in my opinion.

 

Best regards

Tomas

" I repeat: Pico has nothing to do in a pure and good Audio PC, in my opinion "

I agree

https://smallformfactor.net/reviews/powersupplies/hdplex-400w-hifi-dc-atx-next-generation