pico power?

[Tomslin]

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

[Tomslin]

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

[Tomslin]

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.

 

[Tomslin]

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.

[Tomslin]

12 hours ago, the_doc735 said:

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!

It's like pour the money down the drain by buying a super expensive LPS (Paul Hynes etc) for to power a Pico. If you have chosen to use Pico, you can power it with anything that provides fairly pure DC. But to power it with SMPS (power bricks) will cause audible deterioration. If someone considers Pico sounds good it's really subjective. Many factors that affect on what you are experiencing. I just assert that there are better options than Pico.

16 hours ago, the_doc735 said:

"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)?

No, I think you misunderstand. I don’t mean that jitter are created in the pico itself, which is impossible. Instead, HF interference that come from pico can create jitter in other parts of the system, especially clock circuits and the like. I actually think that's what I experienced when I heard it was worse sound. For the same reason, I don't believe it's so immensely important with the absolute best and cleanest power feed to a pico, at least not as long as it's linear. I absolutely didn’t hear any difference between different linear power sources, not even batteries.

[Tomslin]

9 hours ago, the_doc735 said:

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!

Four such and you have a full rail LPS (ATX compatible). You need 3.3V, 5V and two with 12V. It's not as hard as you think with a little DIY

[Tomslin]

1 hour ago, jabbr said:

 

Yes but realize that there are on board DC/DC converters and perhaps on-chip. 1.8V and 1.2V are common for signals and memory. So no matter what you do, unless you design your own board, or modify a board such as an RPi, you are going to have DC/DC switching (which is the pico)

 

http://www.ldovr.com/category-s/122.htm

Yes, I’m fully aware that there are lots of "DC/DC converters" on the motherboard. Just as you say, we can’t do much about it. But in fact, it will anyway be better if we minimize the sources of interference. Pico is a source for to inject interference, and it's no secret about it. But if everyone can perceive it as worse SQ or not is a completely different issue. Probably not, I would say.

[Tomslin]

4 hours ago, the_doc735 said:

Pardon? I am not understanding this - Sorry!

 

I know the ATX uses 3.3V, 5V and two with 12V.

Buy 4 cheapo LPSU's?

 

Yes, this is a possibility of several when I talking about DIY.

4 hours ago, the_doc735 said:

what options are better than PICO? Please give examples? Thanks!

 

Sorry, but I start to think you're kidding with me. I have given you examples and suggestions yet from the beginning of this discussion. If you mean that search the Internet then you can do the job yourself