cheap/chinese LPSU's - minefield?

[jabbr]

19 minutes ago, the_doc735 said:

 

 

@jabbr   ...who said:

 ... the ones I have and refer to as the "Ultra el-cheapo" are similar to: https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC5V-2-5A-R-core-transformer-L6-37/123286410738?hash=item1cb47155f2:g:gtUAAOSwJslbK4AI -- they have different VA ranges, and some are similar to the Sigma 11 design with a discrete current-mirror MOSFET pass transistor, zener diode design. Thanks to @look&listen for pointing out the similarities to me.

 

*************************************************************************************************

 

Looks like same thing to me?

 

I suspect that many of these, despite being sold under different names, are either made in the same place, if not identical, because the internal photos, and cases look so similar. Notable for the easily identifiable R-core transformer. I haven't spent too much time thinking about these nor measuring them because I generally use as a "pre-regulator" to supply a better on-board regulator. 

 

Decide for yourself if you need something different. I power my PC with an ATX supply, and my network equipment plugs into the wall. I use these to replace "wall warts".  

[jabbr]

11 hours ago, the_doc735 said:

Something not right here! Can either of you clarify this conumdrum please? Many thanks!

I have built, and I own a number of power supplies — the ones I buy rather than build are generally to replace cheap wall warts in noncritucal situations and when I know the supply is being used as a preregulator. Teddy Pardo is a name brand vendor whose supplies are reasonable and which compare well in the Linear Audio testing. 

 

Current mirror/zener diode regulators are a common configuration —the Salas Reflektor-D uses in shunt config and the Sigma 11 uses with MOSFET pass — I don’t know the actual IP status around this basic circuit and would  suspect that if there is a patent that it’s expired, in any case it’s a well known design pattern. The sigma 11 is reportedly “open source” on the amb.org website — looks like a good design. Did Amb get its ideas from DIYAudio?

 

I do do love the Salas Shunt for analog and Reflektor-D for digital and if anyone wants to build, the boards/kits are available through DIYAudio.com 

 

In any case life is short and sometimes easier to pick up a cheap LPSU to replace a wall wart. I don’t spend any anxiety worrying about stuff that is upstream of my fiberoptic isolation network.

[jabbr]

1 hour ago, barrows said:

 

https://www.amb.org/audio/

 

They do not license their designs to Chinese vendors, so anything using a sigma11 circuit would be unauthorized.

 

I didn’t ever hear of Sigma 11 or amb.org before @look&listen pointed out to me, so let me give my impressions:

 

a) use of “.org” is for nonprofits and amb.org advertises “open source” — I take open source very seriously and would like to see the exact open source license they are offering — otherwise false advertising!

b) is this a business?

c) do they own right that would enable them to license?

d) if the design was through “users” then who owns the rights? Does the owner of AMB Labs get rights to a design done through the community etc?

 

I wouldn’t be so sure here — in any case I quickly recognized a well known design pattern — the parts to make it are dirt cheap and hence little risk of counterfeit!  and I looked at the Sigma 11 circuit and immediately recognized the current mirror — knew it from Reflektor-D — but it’s in pass not shunt config, so looks good for higher current designs  

 

Bother to measure the “ultra el cheapo”? — which really are a variety of power supplies not one circuit? If not, have you “listened” to one? They sound as wonderful powering a low powered NAS or WiFi router as the music which flow through them!

[jabbr]

5 minutes ago, barrows said:

As to the meaning of "open source" my understanding is that for AMB designs, this means they are free to use for individuals, but not for commercial purposes.  Considering the effort put in by the designer in maintaining the website, designing and selling PCBs, and the very, very detailed instruction and support provided there, if it is not illegal to copy their designs, it is certainly very bad form and to be frowned upon.

 

What evidence do you have that they copied the AMB design? Why are you saying that? I said that the designs sound similar but honestly do you consider a "current mirror, zener diode, MOSFET transistor pass" to be an AMB proprietary design? Do you think that AMB invented this design pattern? 

Really?

 

[jabbr]

8 minutes ago, barrows said:

Perhaps i am mistaken.  lookandlisten described the circuit as sigma11 in this thread, if it is not then that is another thing.

 

I am well aware of the Chinese tendency to revise engineer most of the designs which come out of China, everyone in the industry deals with this on a regular basis, so if it is a direct copy I am not surprised, but perhaps I misunderstood lookedlisten's post.

 

I have also seen the notifications at AMB labs' website warning of the clone PCBs available on eBay.

 

Right but consider this: https://patentimages.storage.googleapis.com/4a/5d/02/fb481b20f81835/US5955915.pdf

patent from 1999

(including figure 2 which is prior art)

[jabbr]

40 minutes ago, look&listen said:

Research many things on eBay & see 5-6 different 'variants' from different listings & sellers.

 

Yeah and your particular vendor has serious QA issues ... 

 

I've used this: https://www.ebay.com/itm/Finished-100VA-Ultra-Low-Noise-linear-Power-supply-ouptut-9v-12v-19v-24v-etc/221884083511?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

and the ZeroZone:

https://www.ebay.com/itm/ZEROZONE-100VA-100W-HIFI-Linear-Power-supply-DC-19V-TOP-LPS-for-amp-DAC-PC/321906781523?hash=item4af323ad53:g:bXQAAOSw~bFWM0c0

without having to repair each one before use ?

[jabbr]

8 minutes ago, barrows said:

I understand that similar (but not identical) circuits have existed for a long time, still, it would appear to me that marketing a commercial product as sigma11 is in direct violation of the above, at least in spirit if not legally.  The violation of that spirit alone is enough for me to accept that it is wrong.

 

Ok look, let's be very clear: I haven't seen one marketed as "Sigma 11", nor is there anything on ebay labeled "Sigma 11". can you provide a link? Without a link you are spreading FUD.

 

Why are you persisting in this despite lack of evidence?, @look&listen clarified the situation "the boards look similar", yep they have 4 small transistors, 2 larger transistors and a bunch of caps... and heatsinks... c'mon man.

 

Who makes your boards? solid-run?

[jabbr]

Ok here is this: https://www.ebay.com/itm/Assembled-S11-SUPER-linear-regulated-power-supply-board-LPS-PSU/111820643468?hash=item1a09079c8c:g:lNIAAOSw14xWQXTH

 

Best I can tell this is a specific vendor, and very upfront about what it is: indeed claims to be the sigma11 PCB design -- which would be copyrighted-- this is not a full supply. They state its "open source" etc, so ...??

 

The supplies that I have, are not this, don't resemble on the inside -- though the circuits may be similar. The discussion that I had with @look&listen was not about this product.

 

None of the links that I've posted appear to be direct sigma 11 copies nor do they claim to be.

[jabbr]

2 minutes ago, barrows said:

@jabbr,  The above quote suggests to me that these companies are marketing the product as "sigma11", I am reading this wrong?

 

There appears to be a board (not an assembled PSU) branded "ZeroZone" and listed by an ebay vendor which does claim to the "Sigma 11" ... fair enough

 

There are a whole bunch of other boards which don't claim to be "Sigma 11" but are discrete zener diode, MOSFET pass transistor based PSUs ... some of which I have, and these have R-core transformers ... again, the photos of the PCBs are not direct copies of the Sigma11 nor are they marketed as S11 or Sigma 11. 

 

I don't own a direct Sigma 11 copy, nor have ever posted a link to one. So I wouldn't say "companies" ?‍♂️

In some cases they give testing details and might claim 10 microvolt noise etc.

 

 

2 minutes ago, barrows said:

 

Sonore designs and builds are own products.  John Swenson does our high speed PCB design and I do the power supply design (schematic/protos) and internal layout, and we use a sub contractor to layout the power supply boards.  We also use a small processor daughter board from a third party supplier, which mounts to the main board, as developing this ourselves, while possible, would add no benefit to our products, but would raise the price due to the development time involved.  

...

 

Hey no problem ... I'm just suggesting that your circuit will resemble another board with iMX-6 processor -- yes, the processor SOM is an excellent approach -- and your "custom OS" is a custom Linux distribution (the kernel is of course open-source Linux). My point is that design patterns are shared in the industry and there are many circuit and software similarities. I'm a big fan of open source and also sensitive to people stealing IP, and the board labelled "S11" seems to do that. The others might just use a similar circuit/design pattern.

 

 

[jabbr]

3 minutes ago, the_doc735 said:

four hours ago I posted this:

"So, if I get something like this and a well informed person on here says that some components are not that good! ...couldn't I simply replace the low quality items with things like: Mundorf caps, schottky diodes/rectifiers, metal film resistors etc?   (to upgrade the device to a better standard)? "

ON topic to my original question in my thread, but unfortunately @jabbr & @barrows decided to have a little argument, and as a consequence my question seems to be overlooked! I don't mind their discussion, quite interesting actually! But I wouldn't mind some help also please.

Thank you!

 

First I stand corrected @barrows -- there are chinese PSUs being marketed as "sigma 11" (s11 is close enough in my book) and they advertise using the S11 pcb design so that's explicit and blatant -- I agree that those shouldn't be bought.

 

Second, in order to "upgrade" you need the schematic. What I like about these are that they include the case and r-core so you'd have to figure that out. I guess you could start replacing parts but better to just buy a board from amb.org and parts and build it from scratch, and that way you know what you are getting. You still need a case and transformer so you could start with the PSU and upgrade the entire board.

[jabbr]

1 minute ago, the_doc735 said:

thank you, couldn't I do the same with the 4 way unit I suggested? "this"   or is one tranny bad with 4 boards, for some reason?

 

We’ve had a lot of confusion by discussing products we aren’t familiar with and I’m not going to comment on anything I haven’t used. I’ve posted links  — if you want something else, eBay and Alibaba are wide open to you.

[jabbr]

6 hours ago, the_doc735 said:

Please see my reply to @Superdad  above (4 posts back) for area's that I need help with!

e.g. what is a suitable tranny for,four of these boards?

cheers!

 

 

To start: for your 12V supply, what is the average voltage you want to supply your regulator board?

How many amps do you need for each voltage?

[jabbr]

20 minutes ago, the_doc735 said:

thanks!

a few posts back I already said: "I don’t know the load/amperage requirements for the 4 DC mobo inputs! (i.e. 3.3v/5v/12v/12v)."

I don;t know the average voltage? I thought a 12v supply would be OK for a 12v mobo input? In the same way you would buy a 9v wall wart for a 9v appliance.

cheers!

 

If you don't know, you don't have a way to decide which transformer you need. These are basic questions. Again:

 

What voltage do you want to supply your regulator board? The board is designed to output 12V, what is the input?

[jabbr]

3 minutes ago, Superdad said:

 

Well not only that, but most transformer manufacturers quote the AC output voltage of their secondaries at the max current rating for that winding.  At lower loads the voltage is going to be a lot higher so consideration (and calculation of rectified DC voltage levels) of that  comes in right away, lest the regulator board gets forced to handle a large drop.

 

Honestly, given @the_doc735's statement that he "thought the voltage range on that tranny was zero –up to- 40V (x2) & zero –up to- 15V" (trans secondaries don't have a "range" Doc), it is clear that he ought not be trying to design and build a big power supply himself.

I can browse automotive engine catalogs all day, but I'm not going to drop by my local mechanic and ask him to tell me how to specify, assemble, install, and test a cylinder head from a kit of parts. Maybe I'll ask the owner at our local fine restaurant to loan me her chef for an evening to teach me how to cook better. 

 

Sorry to be snarky, but I really think he missed the points of my prior two posts.  So I'll stop now.  

 

 

 

Yeah I read.

 

There are a few issues about optimal PSU design and there's also a lot available on the web. Trying to start at the most basic. Sure you can feed 40V into a 3.3V regulator -- that's called a linear space heater! ?... I haven't gotten to the calculation for heatsink yet  

 

I advise anyone interested in DIY audio to build the DIYAudio ACA first! https://diyaudiostore.com/collections/kits/products/amp-camp-amp-kit?variant=7072933085218

[jabbr]

41 minutes ago, the_doc735 said:

well, if you mean "the mains" its 220v UK?

 

No. You don't feed 220v AC into your regulator board. What do you feed into your regulator board. Lets assume the board puts out 12v, has a ground, and has an input. What is the input?

[jabbr]

18 minutes ago, the_doc735 said:

I really appreciate what you are trying to do here, but "the penny still hasn't dropped"? The input from the transformer to the board? Maybe a diagram would help? Cheers!

 

You need to figure this out before you can begin to build a power supply.

 

There is no "one right answer -- it depends on the board you select. 

 

Draw a schematic of the circuit you are planning -- there is no one answer, it depends on the design you select.

 

If you need help, look up examples of linear power supply designs on the web. There are many examples.

[jabbr]

2 hours ago, the_doc735 said:

This board was recommended by @look&listen , he has been using it for nine months with no issues.

https://www.ebay.co.uk/itm/131588996943?ul_noapp=true

 

...maybe he knows the input voltage?

 

I understand, and no doubt he has it working, but you are the one who wants to use it to design a new product and you are the one who needs the answer. If you can't get the answer then either figure it out or use something else. The advantage for you of buying a product that is complete is that you don't need to answer these questions (of course you won't learn that way either) but if you do want to learn there is a whole wide internet at your fingertips that will enable you to answer these questions.

 

(I don't own, have never built nor want a linear powered ATX supply because I focus on low powered boards/streamers next to my DACs)

[jabbr]

5 hours ago, Superdad said:

Well not only that, but most transformer manufacturers quote the AC output voltage of their secondaries at the max current rating for that winding.  At lower loads the voltage is going to be a lot higher so consideration (and calculation of rectified DC voltage levels) of that  comes in right away, lest the regulator board gets forced to handle a rather large drop.

 

 

Baby steps, baby steps ... that's why its called the "Burning Amp" festival  

 

But ... slightly larger drop and lower amps generally is still lower wattage the heatsink needs to dissipate ?‍♂️

 

[jabbr]

28 minutes ago, Superdad said:

Burning Amp, Burning Man.... Due to my thinning pate I recently came up with an idea for a party festival for middle-aged men, to be held not in the desert but someplace rather shady like an Oregon forest.   It’s going to be called “Balding Man.”  Sponsors will include Rogaine and there will be booths selling dome polish and contests for best combover, etc.. 

 

 

Too much hair? ... what lab supplies are those?

 

Also what values of SuperCaps for your combovers? 3 way?

[jabbr]

13 minutes ago, the_doc735 said:

Ah Ah! tried DIYAudio quite a while ago and they said "we don't teach, buy a book".

Cheers!

 

I think that’s good advice. The question I asked you was very very basic and if you aren’t able to answer it, why do you expect people to answer these questions for you? — yes you should get an introductory electronics textbook and read it. Or take a class at a local university or community college or hire a tutor. You need to make some effort to educate yourself.

 

Or not.

 

and don’t tell me that you already know about electronics because you’ve been doing it for 42 years because if you understood what you were doing you could figure out what transformer you need.

[jabbr]

There are many online tutorials.

[jabbr]

43 minutes ago, the_doc735 said:

At this stage he asks if I am attempting to build LPSU myself to save on costs? I said: "yes".

 

This is my issue over, and over, you should not worry that you will be missing out by using an SMPS to power your PC!

 

I am not arguing against hobbyists who have money to spare, and who wish to experiment with LPS on their PC, or fancy AC power cables, or USB cables etc, but the idea that you are missing out on a great audio experience because you can't afford an expensive power supply, or AC power cable etc is just wrong.

 

(I eat my own dog food btw: I have a range of cheap to top shelf equipment --- oops I just bought a pair of FirstWatt SIT-1 amps -- list price of $500/watt)

 

On the other hand if you want to learn how to build an LPS, then learn...

[jabbr]

14 minutes ago, the_doc735 said:

 

So, is everyone on here saying don't bother with cheap (or expensive) LPSU ,waste of time and money! SMPS is better? This is the impression I am getting from @jabbr 

 

To be clear: this all depends on your budget — if you can afford then get an LPS and tell for yourself if it’s better. 

 

If you are on a budget then you can almost certainly improve your SQ more by upgrading your speakers/headphones or amp or DAC.

 

You are also better off using a very low powered renderer — this has all been talked to death.

 

If you have $$$ to experiment and you’ve already optimized everything else then get an LPS. I don’t have on in my server or NAS but do in my very low powered renderers.

 

 

[jabbr]

45 minutes ago, the_doc735 said:

Thanks, but need a bit of clarification? You use both SMPS & LPSU?

Yes I use ATX PSUs in NAS and upsampling server — LPSU to power renderers/NAA

[jabbr]

3 minutes ago, the_doc735 said:

Many Thanks!

You should also realize that most boards — including motherboards and PCIe cards and drives have onboard DC/DC converters eg 3.3, 2.5, 1.8 and 1.1V so your quest to entirely eliminate SMPS may be rather difficult unless you move to a renderer.