cheap/chinese LPSU's - minefield?

the_doc735 · September 20, 2018

...did a quick search for this before posting and can't find a topic with this title, so..........

thinking of purchasing el cheapo LPSU's, one of the main outlets being ebay for example.

Does anyone have any advice in this minefield of devices as to what to definitely avoid at all costs and which are a much better bet, i.e. route out the cowboys and point out the good ones amongst the bunch?

e.g. wolf, I.AM.D, Breeze, ZeroZone, Weiliang, Studer, Jays, etc.

https://www.ebay.co.uk/itm/NEW-25W-TALEMA-Ultra-Low-Noise-LPS-DC-5V-3-5A-Linear-Power-Supply-psu-HIFI-AUDIO/142049588319?hash=item2112d0b45f:g:arkAAOSwAPlXgK5G
https://www.ebay.co.uk/itm/120VA-HIFI-Ultra-low-noise-Linear-Power-supply-DC5V-9V-12V-15V-18V-24V-LPS-PSU/272753485878?hash=item3f815fe836:g:L94AAOSwB3pbcqVC
https://www.ebay.co.uk/itm/HiFi-PSU-TALEMA-25VA-Linear-Power-supply-DC5V-DC9V-DC12V-DC15V-PSU-for-optional/271905173892?hash=item3f4ecfb184:g:RMgAAOSwHUtazdlD

https://www.ebay.co.uk/itm/Finished-65VA-Ultra-Low-Noise-linear-Power-supply-5V-9V-12V-15V-18V-etc-L158/131585252822?hash=item1ea3179dd6:g:9CkAAOSwDNdVysUL
https://www.ebay.co.uk/itm/SUPER-3-5A-DC-Linear-Regulator-power-5V-7-5V-9V-12V-16V-24V-TALEMA-transformer/253615218117?hash=item3b0ca51dc5:m:maO4N_z9YhjSyHU7eHWUAhQ
https://www.ebay.co.uk/itm/50VA-HIFI-Ultra-low-noise-Linear-Power-supply-DC5V-9V-12V-15V-18V-24V-LPS-PSU/112445361966?hash=item1a2e440f2e:g:SXwAAOSwFJBZQ-HA
https://www.ebay.co.uk/itm/Finished-65VA-Ultra-Low-Noise-linear-Power-supply-5V-9V-12V-15V-18V-etc/121963519293?hash=item1c65979d3d:m:m3nxjeKDwfuACl3NOPZSAZQ

sandyk · September 20, 2018

the_doc735

You need to specify the output voltages and currents required, as well as the price range.

Also, whether they are needed for applications where very low noise is required, or just for areas where you wish to replace an existing SMPS plugpack where the requirements are more relaxed and a cheaper LPSU will be adequate..

the_doc735 · September 20, 2018

1 hour ago, sandyk said:

the_doc735

You need to specify the output voltages and currents required, as well as the price range.

Also, whether they are needed for applications where very low noise is required, or just for areas where you wish to replace an existing SMPS plugpack where the requirements are more relaxed and a cheaper LPSU will be adequate..

I just wondered if there were any general preferences of say manufacturer etc? (without specifics) - many thanks!

To start with looking at the 4 wall warts @ the top of the picture:

NAS: 12V 2A (supplied with 12V 5A) actual use - 16.79 W (Access), 5.16 W (Hibernation)

ROUTER: 12V 2A

FMC's (x2): 9V 0.6A

Crossed TV out because going headless hopefully. Access via wireless general purpose laptop for PLAYER PC (same as router/NAS).

Panelhead · September 20, 2018

I have only owned the Jay’s from the list. Worked very well. Not sure it betters the iFi iPower sonically.

The Jay’s unit seemed to be built to order when I purchased mine. Sold one when moving away from using 2 channel dacs.

The Jay’s is twice the price of an iPower.

the_doc735 · September 21, 2018

20 hours ago, Panelhead said:

I have only owned the Jay’s from the list. Worked very well. Not sure it betters the iFi iPower sonically.

The Jay’s unit seemed to be built to order when I purchased mine. Sold one when moving away from using 2 channel dacs.

The Jay’s is twice the price of an iPower.

read bad things on the web about the iFi iPower units! ...e.g. avoid! etc. etc.

the_doc735 · September 21, 2018

@jabbr @look&listen

these: https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC9V-2A-R-core-transformer-L6-51/192581769256 have been mentioned by jabbr/look&listen as pretty good value for money on less important powered components within a system, probably just as much for their interference going BACKWARDS (into the rest of the network), as much as their interference going forwards? i.e. caused by wall wart SMPS.

When it comes to the crucial items like the PLAYER PC, perhaps need to go 'up market' LPSU?

Monge · September 21, 2018

@the_doc735 Thanks for creating this thread ?

I would be nice to have one place for looking at a Cheap LPSU.

I’ve heard good things about this for a router

https://www.ebay.com/itm/131867485038?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It’s a little more expensive.

Cheers Monge

look&listen · September 21, 2018

33 minutes ago, Monge said:

I’ve heard good things about this for a router

https://www.ebay.com/itm/131867485038?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

For $187 you get R-core xformer, sigma11 variant reg. circuit, but crap full wave bridge rectifier.

Maybe look at

https://www.ebay.com/itm/Finished-100VA-Ultra-Low-Noise-Linear-Power-Supply-Ouptut-9v-12v-19v-24v-R1716/141770497380?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

For $156 get above, but Ultra-Fast Recovery diodes, bigger box to separate weak fields & heat, different S11 variant. I have one for 9 mo. & all Ok (power server).

But for all el-cheapo LPSU's, not just these, important to observe 2 rules!

1) Never use close to rated output specs. Asking for trouble & @Superdad has shown regulation breakdown, even unit failure.

2) Always inspect inside new unit for any issues- loose parts, bad soldering, &c. (QA cost money, not spent on el-cheapo's)

Monge · September 21, 2018

33 minutes ago, look&listen said:

For $187 you get R-core xformer, sigma11 variant reg. circuit, but crap full wave bridge rectifier.

Maybe look at

https://www.ebay.com/itm/Finished-100VA-Ultra-Low-Noise-Linear-Power-Supply-Ouptut-9v-12v-19v-24v-R1716/141770497380?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

For $156 get above, but Ultra-Fast Recovery diodes, bigger box to separate weak fields & heat, different S11 variant. I have one for 9 mo. & all Ok (power server).

But for all el-cheapo LPSU's, not just these, important to observe 2 rules!

1) Never use close to rated output specs. Asking for trouble & @Superdad has shown regulation breakdown, even unit failure.

2) Always inspect inside new unit for any issues- loose parts, bad soldering, &c. (QA cost money, not spent on el-cheapo's)

@look&listen Thanks for correcting me and the advice.

For ny own router I’m using a BOTW P&P Eco.

I have 2 TP link MC200CM 9V/0.6A version 2.23 in a drawer that I want to try again.

So this one Will be OK?

https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC9V-2A-R-core-transformer-L6-51/192581769256

Thanks In advance.

Cheers Monge

the_doc735 · September 21, 2018

59 minutes ago, look&listen said:

For $187 you get R-core xformer, sigma11 variant reg. circuit, but crap full wave bridge rectifier.

Maybe look at

https://www.ebay.com/itm/Finished-100VA-Ultra-Low-Noise-Linear-Power-Supply-Ouptut-9v-12v-19v-24v-R1716/141770497380?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

For $156 get above, but Ultra-Fast Recovery diodes, bigger box to separate weak fields & heat, different S11 variant. I have one for 9 mo. & all Ok (power server).

But for all el-cheapo LPSU's, not just these, important to observe 2 rules!

1) Never use close to rated output specs. Asking for trouble & @Superdad has shown regulation breakdown, even unit failure.

2) Always inspect inside new unit for any issues- loose parts, bad soldering, &c. (QA cost money, not spent on el-cheapo's)

yes, thank you! These are exactly the kind of replies we need here to help us avoid any total junk devices i.e. dig out the best el cheapo's and leave the rest alone! Again, thanks!

look&listen · September 21, 2018

8 minutes ago, Monge said:

So this one Will be OK?

https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC9V-2A-R-core-transformer-L6-51/192581769256

$90, R-core xformer nice, but not enough information available in listing to know type/kind rectifiers, regulator? Suspect if was good, would be praised in ad copy, so probably not. Don't like too small box for all parts, could be heat problem if driven hard (maybe medium too?).

Sorry, but not yet found preferred 30W LPSU from China. (mine DIY)

the_doc735 · September 21, 2018

3 hours ago, look&listen said:

https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC9V-2A-R-core-transformer-L6-51/192581769256

Quote

$90, R-core xformer nice, but not enough information available in listing to know type/kind rectifiers, regulator? Suspect if was good, would be praised in ad copy, so probably not. Don't like too small box for all parts, could be heat problem if driven hard (maybe medium too?).

Sorry, but not yet found preferred 30W LPSU from China. (mine DIY)

@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?

the_doc735 · September 21, 2018

swagman lab

can anyone recommend or condemn these LPSU's? (various models available)

from hong kong

the_doc735 · September 21, 2018

https://www.ebay.co.uk/itm/50VA-HIFI-Ultra-low-Noise-Linear-Power-Supply-DC5V-9V-12V-15V-18V-24V-LPS-PSU/273372400529?hash=item3fa643cb91:g:XBgAAOSwIUZbZS1Q

looking for a blessing (or not) as the case maybe on this LPSU, to me it looks really good, but perhaps you know different?

thanks!

jabbr · September 21, 2018

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".

the_doc735 · September 21, 2018

11 minutes ago, jabbr said:

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".

Deciding for myself means I just might buy junk unfortunately.

Why do you use ATX on your PC & plug your network into a wall socket (direct?)? ...when so many threads on so many forums go on & on about LPSU being great for PC's playing audio? + e.g. mains filters and conditioners, dedicated mains circuits, etc etc. No one has ever said this before to me! WOW moment!!

I have the Seasonic Prime Ultra ’80+’ Titanium 650 Watt ATX M-PSU. 10 mV ripple max. Everyone says this is no good for music and I should get rid of it, SMPS is no good for music?

Thanks!

sandyk · September 22, 2018

I also use the internal 650W SMPS in my PC, but use additional voltage regulation to provide cleaner power to several of the internal SATA devices.(Optical device and 2 SATA SSDs) My PC is also powered via a substantial DIY A.C. Filter board to further reduce crap going back into the A.C. mains supply.

I don't believe in using numerous additional Linear PSUs to provide power for internal devices due to the need to avoid Earth Loops for best results.

You can't always directly hear the effects of earth loops, such as mains frequency related hum, bur they do cause degradation.

IIRC, Jon prefers to clean up any residual noise problems using S.O.A. Optical fibre cable distribution.

the_doc735 · September 22, 2018

1 hour ago, sandyk said:

I also use the internal 650W SMPS in my PC, but use additional voltage regulation to provide cleaner power to several of the internal SATA devices.(Optical device and 2 SATA SSDs) My PC is also powered via a substantial DIY A.C. Filter board to further reduce crap going back into the A.C. mains supply.

I don't believe in using numerous additional Linear PSUs to provide power for internal devices due to the need to avoid Earth Loops for best results.

You can't always directly hear the effects of earth loops, such as mains frequency related hum, bur they do cause degradation.

IIRC, Jon prefers to clean up any residual noise problems using S.O.A. Optical fibre cable distribution.

"a substantial DIY A.C. Filter board to further reduce crap going back into the A.C. mains". Please tell me more with pics. please?

"S.O.A. Optical fibre cable distribution". Please elaborate? thank you!

I don't have optical devices in PC OR SSD's; only M.2 NVMe storage card.

"I also use the internal 650W SMPS in my PC," - WOW!! - so this is 'the other side of the coin'?

"I don't believe in using numerous additional Linear PSUs to provide power for internal devices due to the need to avoid Earth Loops". So, you don't believe in using four LPSU's for the mobo (12v CPU/ATX 12v/5v/3.3v)?

barrows · September 22, 2018

Simple, do not purchase cheap Chinese power supplies. Instead, purchase a high quality supply from a reputable company/builder, who you trust.

Look, you do not really "need" these at all as most who are looking to purchase a linear power supply are doing so to replace a cheap SMPS, so if you really want an upgrade, get something good. Just because a supply is linear does not mean it is good!

Additionally, the s11 power circuit used by some of the supplies mentioned above is stolen intellectual property, do not support companies that steal other's work, it makes you an accomplice to theft.

Also, if one has enough knowledge to determine if a given Chinese supply might actually be good, then that person has enough knowledge to build their own power supply, and i would highly recommend doing that, as then the user can build a power supply ideally suited for their load and its requirements.

The Chinese use counterfeit parts, poor PCB quality, and usually, barely adequate designs. If one is looking for an upgrade, get something of quality.

the_doc735 · September 22, 2018

@jabbr @look&listen

with respect, please forgive me but I have a bit of a dilemma 'here'. I have obviously misunderstood something in the previous text's.

Jabbr says he purchased the: 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 with help and advice from 'look&listen'; but now 'look&listen' says: "$90, R-core xformer nice, but not enough information available in listing to know type/kind rectifiers, regulator? Suspect if was good, would be praised in ad copy, so probably not (a good LPSU). Don't like too small box for all parts, could be heat problem if driven hard (maybe medium too?)."

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

sandyk · September 22, 2018

2 hours ago, the_doc735 said:

"a substantial DIY A.C. Filter board to further reduce crap going back into the A.C. mains". Please tell me more with pics. please?

"S.O.A. Optical fibre cable distribution". Please elaborate? thank you!

I don't have optical devices in PC OR SSD's; only M.2 NVMe storage card.

"I also use the internal 650W SMPS in my PC," - WOW!! - so this is 'the other side of the coin'?

"I don't believe in using numerous additional Linear PSUs to provide power for internal devices due to the need to avoid Earth Loops". So, you don't believe in using four LPSU's for the mobo (12v CPU/ATX 12v/5v/3.3v)?

The DIY mains filter that I used is no longer obtainable on ebay. It required assembly (soldering) and I also added a few varistors for added protection against mains voltage spikes , and put it in a plastic case with a couple of mains sockets mounted on top.

Ask Jon what he uses to clean up and distribute the signal. He uses Pro type Optical gear to do that.

I prefer to do the cleaning up to improve Signal Integrity before it leaves the computer.

There is more than one way to " skin a cat ".

No, I don't believe in using four LPSU's for the mobo (12v CPU/ATX 12v/5v/3.3v)?

OTOH, if they were all in the same case and well isolated from each other electrically (e.g. separate transformers)

that could be a different matter, but perhaps well and truly overkill ?

the_doc735 · September 22, 2018

42 minutes ago, sandyk said:

The DIY mains filter that I used is no longer obtainable on ebay. It required assembly (soldering) and I also added a few varistors for added protection against mains voltage spikes , and put it in a plastic case with a couple of mains sockets mounted on top.

Ask Jon what he uses to clean up and distribute the signal. He uses Pro type Optical gear to do that.

I prefer to do the cleaning up to improve Signal Integrity before it leaves the computer.

There is more than one way to " skin a cat ".

No, I don't believe in using four LPSU's for the mobo (12v CPU/ATX 12v/5v/3.3v)?

OTOH, if they were all in the same case and well isolated from each other electrically (e.g. separate transformers)

that could be a different matter, but perhaps well and truly overkill ?

https://www.ebay.co.uk/itm/Finished-4-way-High-Current-Hifi-linear-Power-supply-DC5V-9V-12V-19V-LPS-L4-21/123099825369?hash=item1ca95244d9:g:gGIAAOSwaZFa4KhG

https://www.ebay.co.uk/itm/HIFI-3-way-linear-power-supply-DC5V-3A-DC9V-2-5A-DC12V-2-5A-L6-38/123203794481?hash=item1caf84b631:g:D8AAAOSwcSJa8xMw

the_doc735 · September 22, 2018

2 hours ago, barrows said:

Simple, do not purchase cheap Chinese power supplies. Instead, purchase a high quality supply from a reputable company/builder, who you trust.

Look, you do not really "need" these at all as most who are looking to purchase a linear power supply are doing so to replace a cheap SMPS, so if you really want an upgrade, get something good. Just because a supply is linear does not mean it is good!

Additionally, the s11 power circuit used by some of the supplies mentioned above is stolen intellectual property, do not support companies that steal other's work, it makes you an accomplice to theft.

Also, if one has enough knowledge to determine if a given Chinese supply might actually be good, then that person has enough knowledge to build their own power supply, and i would highly recommend doing that, as then the user can build a power supply ideally suited for their load and its requirements.

The Chinese use counterfeit parts, poor PCB quality, and usually, barely adequate designs. If one is looking for an upgrade, get something of quality.

these are quite serious allegations to make! please don't put yourself at risk of a 'LIBEL' court case from china! Do you have any proof/evidence to back up your case? OR, do you expect people to believe your word alone? take care.

sandyk · September 22, 2018

31 minutes ago, the_doc735 said:

https://www.ebay.co.uk/itm/Finished-4-way-High-Current-Hifi-linear-Power-supply-DC5V-9V-12V-19V-LPS-L4-21/123099825369?hash=item1ca95244d9:g:gGIAAOSwaZFa4KhG

https://www.ebay.co.uk/itm/HIFI-3-way-linear-power-supply-DC5V-3A-DC9V-2-5A-DC12V-2-5A-L6-38/123203794481?hash=item1caf84b631:g:D8AAAOSwcSJa8xMw

Neither of these supplies have a 3.3V output as you specified.

mourip · September 22, 2018

21 hours ago, Monge said:

@look&listen Thanks for correcting me and the advice.

For ny own router I’m using a BOTW P&P Eco.

I have 2 TP link MC200CM 9V/0.6A version 2.23 in a drawer that I want to try again.

So this one Will be OK?

https://www.ebay.co.uk/itm/30W-Hifi-Ultra-low-noise-Linear-Power-supply-DC9V-2A-R-core-transformer-L6-51/192581769256

Thanks In advance.

Cheers Monge

I have been using a Teradak unit for several years. They even have an internal potentiometer that you can use to tweak the voltage a bit.

https://www.ebay.com/itm/TeraDak-DC-30W-TOUCH-DC9V-2A-Hi-Fi-Audio-Linear-Power-Supply-/130906580297?hash=item1e7aa3e549

cheap/chinese LPSU's - minefield?

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