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Low noise power supplies, 5v, 9v & 12v.

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I had a good chat with Marc the other day & we both agreed that some good quality low noise 5v, 9v & 12v locally produced power supplies would go down well.

I have already done quite a bit work in this area & have built several 12v Intel NUC psu's which customers were most impressed with. I know there are lots of low priced units on EBay but they generally use low quality parts especially in the filter cap, diode  area & the mains input voltage is often a bit low ie. 220v. There are some great units coming out of the US but with our plummeting dollar & high postal cost don't represent good value. What I am proposing is two models & both  will be powered by external fully AUS  approved 240v AC transformers. I love using external AC supplies as  I then have full control over rectification filter cap choice etc.. OK so a 5v or 9v (pick voltage on order) at about 2A & a 12v unit at 2.5A. I am limited to these maximum currents by the external transformer choice, trying to keep everything legal & approved. I know you guys like to see massive current ratings but even a mini itx MB only draws about one amp after initial start up surge. I find diode & capacitor choice has a much bigger effect on sonic qualities than an outright current rating.  Case style will be the same as the Klein DAC series as I have this well sorted now. Canadian manufactured Hammond extruded aluminium case with slide in PCB & zero internal wiring. I will be using high spec very low noise regulators. That give great protection & will make them short circuit proof. Noise levels from these are now the same as the boutique  super regs that are so popular.   Marc also suggested the possibility of a DIY version ie populated board only which could be fitted into a custom server case. Lots to think about & any feed back much appreciated.

 

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Is there enough room in the box for 2 x selectable dc outputs? Let's face it, some of us have more than one dc toy! One for SBT, another for usb power for/or another source/server/dac?

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Great idea Clay. It might help if you can provide some measurements for comparison with commercially available units (in particular HDPlex, HS-2 and the like).

Richard

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Great news.

I was lucky to have member @AJ build me one a couple of years ago with dual output. He is in New Zealand now so that is not available AFAIK.

With the US$ where it is I think it is an excellent idea. We need Australian products for ourself.

My wishlist:

  • Choices in enclosure - especially if you are going down the DIY route (Which may or may not be a good business decision?) Also if someone has a Nuc, those of us with OCD want the boxes looking the same - for example: the iFi products and the Cyrus products.
  • One output is not enough. Maybe have a base model with only one output, but I agree with @@christosd that many of us want to power more than one toy. E.g. usb/spdif, squeezebox touch, server/pc, so I think there is demand for models with more than one output.

@@Chanh and @@Tasso what are your comments based on your experiences with music servers?

 

Not sure how  cabling works with all the different connection options out there?

Edited by Jventer

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Great idea Clay. It might help if you can provide some measurements for comparison with commercially available units (in particular HDPlex, HS-2 and the like).

Richard

Agree

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Great idea. I've got a HDPlex unit at the moment and the flexibility of multiple outputs is fantastic.

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Excellent idea - I've often drawn a blank looking locally for a decent power supply.

 

A couple of questions if I may:

 

  • Are you talking about AC to DC power supplies or AC to AC?
  • Will there be options with respect to the output connector as these can come in different sizes?
  • Any possibility of a 24VDC model as this is what I'm looking for for my phono stage?

Thanks Clay.

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 What I am proposing is two models & both  will be powered by external fully AUS  approved 240v AC transformers. I love using external AC supplies as  I then have full control over rectification filter cap choice etc.. OK so a 5v or 9v (pick voltage on order) at about 2A & a 12v unit at 2.5A..... 

Marc also suggested the possibility of a DIY version ie populated board only which could be fitted into a custom server case. Lots to think about & any feed back much appreciated.

Great initiative! I concur that quality diodes and electrolytic are most critical, follow by low noise/ripple regulator(s). Do you have a preliminary schematic in mind? Lastly, what is your estimate cost of the final 12VDC unit?

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OK,  multiply outputs. 5v & 9v in the one box is no problem but adding 12v as well gets a bit tricky. The HDPlex has a multi tapped power transformer. I don't have the luxury & for me to put a 240v transformer in a case I would need C tick & safety approval, big dollars.  Also the total current draw can only be what the transformer is rated to.

For the 5v + 9v supply I would be using a 10v 2.4A external transformer (same as Klein DAC) so the total current output current available would be 2.4A. It sounds like all this this could be quite popular so I could certainly have a range of models including a multi voltage ones. Initially I was thinking  the main applications would be -  DIY music servers using ARM cored boards eg. Rasberry Pi, logitech Squeezeboxs, USB Regens, DAC's & NUCs but I may have to rethink this.

Noise levels.  I was thinking of using say a SOTA low noise reg eg TPS7A4700 (noise 4uVrms 10hz - 100khz) & beefing up the current output to get 2 - 3 Amps. I will have a good look at the noise levels of popular PSU's out there & make sure mine have similar or lower levels.

re question on output. All supplies will run from external AC transformers (240 v AC in) & output DC only voltages.  At this stage no 24v output versions.

PS Hi Chanh, good to hear from you.

Yes I do have a folder with a few favourite schematics. I will post a rough overview once I decide which one to use. I have a nice new 100 mhz Techtronics Scope so I can see results better now.  pricing on 12 v unit, I have done a few of  those before & they sold for $350. I will probably need to go through all the costing again & will do an update shortly.

Edited by Gieseler Audio

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Great idea Clay  :thumb: 

9v + 12v combo unit would be awesome for my pc / sotm card build.

Count me in mate!

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Great news.

I was lucky to have member @AJ build me one a couple of years ago with dual output. He is in New Zealand now so that is not available AFAIK.

With the US$ where it is I think it is an excellent idea. We need Australian products for ourself.

My wishlist:

  • Choices in enclosure - especially if you are going down the DIY route (Which may or may not be a good business decision?) Also if someone has a Nuc, those of us with OCD want the boxes looking the same - for example: the iFi products and the Cyrus products.
  • One output is not enough. Maybe have a base model with only one output, but I agree with @@christosd 2 that many of us want to power more than one toy. E.g. usb/spdif, squeezebox touch, server/pc, so I think there is demand for models woth more than one output.

@@Chanh and @@Tasso what are your comments based on your experiences with music servers?

 

Not sure how  cabling works with all the different connection options out there?

 

 

The option for multiple  voltage output  will be most useful as would multiple outputs. Probably don't need more than 2 outputs but voltage selection for each would be very nice.  If the outputs used good quality connectors  that are easy  to get, building different power cables for different applications will be relatively easy.

 

Possibly should consider an unregulated option to connect with  with ATX style power  interfaces  such as HDPLEX  or generic pico  adapter. These provide their own regulation and perhaps cost and performance advantages  could be gained with  this approach. 

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Hi Clay. I've got a Keces DC116 - which with current exchange rates probably costs a touch over $500. It's dual power - 5v and 9v; both at 2A. 

 

If you can price your units under the $400 mark - my guess is that you would move a lot of them. The 5v and 9v model is perfect for powering a Squeezebox Touch and a Remedy reclocker (both of which I own).

 

 

Chris

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Any chance of a +/-12v supply for us with phono stages that love clean + and - rails?

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Great move I reckon--Pity no 24V 2/3A units though--I use that and have others ask me where to buy

 

Plenty of 2/3motor TT's that need that version to get rid of the Cheap Chinese Wall warts supplied

 

In time hopefully

 

Good one guys!

 

Willco

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Bill - the Klein DAC's need AC input &  these new supplies will be DC output so not suitable. The Klein has a similar power supply to these that is build into the DAC anyway.

Willco - I can get a suitable external 24V AC transformer so a 24v DC output supply is definitely workable,   I will look into it as well.

Regards Clay

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OK I have taken some DC current measurements on my music server. It is using a Jetway mini itx M/B, Sotm PCI USB card, WD 3.5" HD & a DVD rom drive.

As expected there was a bit of a surge at startup & finally settled down at about 1.6A This is good news as it means the Dai-1chi  2.5A 16v AC external transformer I was planning on using should be fine with a bit of current reserve.

Changing to a SSHD & removing the DVD rom drive reduces  current drain more as well. Based on this the biggest model in my new power supply range would have, 12v + 12v + 9v (maybe a optional 5v as well) So on a average mini itx server build

you will have 12v to go into the DC M/B connection & then 12v or 9V depending in which Sotum card & an optional 5v? for the Paul Pang  USB card. What do you think? any other suggestions?

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Hi Batty,

yes + & - 12v is no problem as that is what the Klein uses & I have that well sorted. Depending on the current drain it might be possible to use the Shunt version that the SE Klein uses. 

Wow, did not realise how popular good low noise power supplies would be. Careful - this may slow down Klein production! :)

Edited by Gieseler Audio

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Hi Batty,

yes + & - 12v is no problem as that is what the Klein uses & I have that well sorted. Depending on the current drain it might be possible to use the Shunt version that the SE Klein uses. 

Wow, did not realise how popular good low noise power supplies would be. Careful - this may slow down Klein production! :)

i think everyone wants to have a good computer based media server, thats include me.. :P

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What do I think? .................. I think you should have posted this a week ago .............. before I ordered the HDPLEX ..................... :( :( ............ :) :)

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Very timely for me too!

Wouldn't a nice (read sexy) vented box with heatsinks be a good idea, even at low current outputs? For those in the tropics of course - we others would just have to stare glassily at it and just know how cool it is.

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Hi,

Good project!

Re the 16v 2.5A AC supply, the maximum DC load current available will be 1.5 amps.

Cheers

John

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Hi Rab,

Sotm mods as follows.

​Replace all the 470uf 16v (9x) generic electros with Panasonic FM series

http://au.element14.com/panasonic-electronic-components/eeu-fm1c471l/aluminum-electrolytic-capacitor/dp/1219462

I would have liked something better but not enough room.

Replace the 3 X 1uf film caps, 5 mm pin pitch so no drop in polypropylene but at least these are only 7.5 pitch 

http://au.element14.com/panasonic-electronic-components/ecw-fd2w105j4/film-capacitor-1uf-450v-5-radial/dp/2413398

Bit messy for me though so I would just go with a good Wima polyester

http://au.element14.com/wima/mks2c041001f00kss/cap-film-pet-1uf-63v-rad/dp/1006040

Now the really good part! Replace one of the USB sockets with a Wurth Electronics filtered types.

http://au.element14.com/wurth-elektronik/8492121/conn-usb-2-0-a-w-esd-emi-filter/dp/2442757

This is like adding a jitter buster but only costs $17

Now the credit for these tips must go to Tam Nguyen from the building the ideal(ish) Music server thread. How much better does it sound? Well I haven't had time to fully evaluate it yet as I only did it this morning.

John, thanks for the current rating tip, I will do some real world testing next week on that external transformer.

cheers  Clay

Edited by Gieseler Audio

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