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

[Gieseler Audio 1,766]

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.

 

[christosd 600]

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?

[Sir Rab of Everest 562]

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

[Jventer 1,558]

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 September 12, 2015 by Jventer

[Jventer 1,558]

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

[~Spyne~ 1,106]

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

[Guest Hensa]

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.

[Chanh 1,142]

 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?

[Gieseler Audio 1,766]

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 September 9, 2015 by Gieseler Audio

[Conch 303]

Great idea Clay   

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

Count me in mate!