Looking to make a Linear Regulated 5 Volt Power Supply (suggestions please)
Mar 27, 2016 at 8:01 PM Thread Starter Post #1 of 12
robertsong

robertsong

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Wondering if anybody can suggest this one:
 
http://www.diyinhk.com/shop/audio-kits/89-08uv-ultralow-noise-dac-power-supply-regulator-3357v-15ax2.html
 
Or maybe something else?
 
What transformer would you recommend?
 
Thanks.
 
Mar 27, 2016 at 9:57 PM Post #5 of 12
Just me, but I would guess 5V means it has something to do with USB power levels.
 
LM317 circuits are documented all over the place.  Avro_Arrow implemented one for our DoodleBug device.  The schematic is here:
http://diyforums.org/Doodlebug/schematic/DoodleBugSchematic.png
(Look at the top of the image for the "POWER" section.)  Avro changed things up by using LEDs to drop the controlling voltage set on the LM317, for both more linear and quieter effects.  It definitely gets down in the double-digit microvolts of noise, perhaps even single digits.
 
What's more important, though (IMHO), is to adjust the voltage output so that it takes advantage of the USB spec's voltage range, meaning adjusting up to 5.25VDC.  Many USB-powered DACs have internal voltage regulators, but even LDO (Low Drop Out) regulators need to burn a little to give a little, so an extra bit of voltage on the incoming side ensures that the DAC's internal regulators have plenty to burn to maintain the regulation.  The regulation, after all, is what is really removing the AC noise.
 
As for power source, there's no need at lower current ratings (500ma and less) to use a big, complicated toroid and messing with mains wiring.  An AC walwart (about 6VAC) or DC unregulated (as opposed to switching) walwart (9VDC or more) will work fine.
 
Mar 27, 2016 at 10:15 PM Post #7 of 12
tomb said:
  Just me, but I would guess 5V means it has something to do with USB power levels.
 
LM317 circuits are documented all over the place.  Avro_Arrow implemented one for our DoodleBug device.  The schematic is here:
http://diyforums.org/Doodlebug/schematic/DoodleBugSchematic.png
(Look at the top of the image for the "POWER" section.)  Avro changed things up by using LEDs to drop the controlling voltage set on the LM317, for both more linear and quieter effects.  It definitely gets down in the double-digit microvolts of noise, perhaps even single digits.
 
What's more important, though (IMHO), is to adjust the voltage output so that it takes advantage of the USB spec's voltage range, meaning adjusting up to 5.25VDC.  Many USB-powered DACs have internal voltage regulators, but even LDO (Low Drop Out) regulators need to burn a little to give a little, so an extra bit of voltage on the incoming side ensures that the DAC's internal regulators have plenty to burn to maintain the regulation.  The regulation, after all, is what is really removing the AC noise.
 
As for power source, there's no need at lower current ratings (500ma and less) to use a big, complicated toroid and messing with mains wiring.  An AC walwart (about 6VAC) or DC unregulated (as opposed to switching) walwart (9VDC or more) will work fine.
Click to expand...

 
Thanks for this info. My goal is make something like this that performs as well or better for less money.
http://www.ebay.com/itm/NEW-TeraDak-DC-30W-TOUCH-DC5V-3A-Linear-precision-linear-regulated-power-supply-/301773952382?hash=item464321157e:g:EnkAAOSwfcVUI5XK
Sound quality is very important for me.
 
Mar 27, 2016 at 10:19 PM Post #8 of 12
That WaveIO can be powered directly from the USB if you want.
 
x2 what tomb said. I'd use a simple lm317 power supply on perfboard (it's like 8 components). I'm going to assume you're sticking that WaveIO into a chassis, so any you're probably going to use a tiny transformer. with 5V output and that device requiring about 500mA, any transformer over 5VA will work. That's TINY.
 
The links you provided was for a 1.5A psu, the second 3A. That's a complete waste as you'll never use that capacity.
 
Spend money on the PSU of the DAC, not the usb converter.
 
Mar 28, 2016 at 12:46 PM Post #9 of 12
fallenangel said:
  That WaveIO can be powered directly from the USB if you want.
 
x2 what tomb said. I'd use a simple lm317 power supply on perfboard (it's like 8 components). I'm going to assume you're sticking that WaveIO into a chassis, so any you're probably going to use a tiny transformer. with 5V output and that device requiring about 500mA, any transformer over 5VA will work. That's TINY.
 
The links you provided was for a 1.5A psu, the second 3A. That's a complete waste as you'll never use that capacity.
 
Spend money on the PSU of the DAC, not the usb converter.
Click to expand...

 
A couple things. My WaveIO is already up and running and used in a separate enclosure (this project is complete). This feeds a Vinnie Rossi LIO which is a far cry from a DIY DAC (no offense). The PSU for the USB converter will also be in a separate enclosure as well. Size of transformer is not an issue and neither is the amperes rating. The only thing that matters to me is sound quality. If this can't be achieved I'll be buying something from Paul Hynes or Teddy Pardo, for example. The best I've heard so far is a Bakoon BPS-02 that I wish I still had, but I don't want to deal with batteries.
 
If your not the guy to help me, that's perfectly fine, FallenAngel. Maybe somebody here else can? Everybody has there differences and we seem to be miles apart.
 
Mar 28, 2016 at 4:21 PM Post #10 of 12
No offence taken, if anything I had a little chuckle. If you simple replace the acronym diy with the word custom, perhaps it will have the connotation more suited to describe what we're referring to. Both tomb and I suggested a simple regulated power supply because that's all that's required to power such a USB converter and anything fancy will be more or less just that, fancy. Twisted pear audio offers a nice shunt regulator power supply, and there are a few other very popular regulated power supplies like the sigma11. Personally, I think it would be massive overkill, but to each their own.
 
Mar 28, 2016 at 6:49 PM Post #11 of 12
Moving the ground from the computer thru the skinny interface cable is the primary advantage an external PSU offers.
(especially given the rated noise performance of the local regulators on the waveIO)
I would rather not have the line filters but if you keep the umbilical short the simple PSU in the first post is adequate.
 
I would suggest asking the vendor what transformer to use with a product from their catalog. :)
 
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