The best Raspberry Pi power supply

Pubblicato il 17 giugno 2013 da admin — 81 Commenti ↓

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Ok, since we already documented a little about the importance of a good PSU (Power Supply Unit) when audio quality is your main concern. As stated earlier, the raspberry pi power supply is also responsible for proper functioning of our tiny device, as a poor quality psu will result almost certainly in a corruption of your SD Card.

So that’s why I’m stressing this a lot. Most of the times, malfunctions of the pi are to be tied with a bad PSU. A proper Raspberry Pi Power Supply must be rated (and comply to ratings…) at 5v ( and real world output should be between 4,75 Vdc and 5,25 Vdc) and at least 1 A (if you plan to connect other devices to your Pi).

I tested different PSUs and these were my results:

These are the PSUs I took for comparison. From left to right: a Sony Xperia mobile charger, 2 cheap chinese Psus and a 1A usb Hub PSU.

Without digging into technical details, I can tell you that best results came with the Xperia Mobile Phone charger. Using the third PSU repeatedly corrupted my SD, while the other 2 were ok but sometimes I heard some pop noises from the loudspeakers. So, choosing the best Raspberry Pi Power supply could seem like a random choice, if you’re luck you’ll get one suitable, if don’t you just buy another one and so on. But we don’t want to just pick a random choice, don’t we?
OK, time to get a better Raspberry Pi PSU, the right way.

If you feel like If you want something done right, do it yourself, there are only 2 options for you, mate. Diy or full Diy.

Or this, which I would like to but I fear it might result in an extremely poor WAF, (even if I’m not married…) :

Full DIY Approach

What we do need here is something that is worth the pain of looking for the components, buying them, solder them on a breadboard and put it in a box. If you are the kind of guy who likes all of this stuff, well, this is for you.

The core of a good PSU is it’s regulator. So, for newbies:

In electronics, a linear regulator is a system used to maintain a steady voltage. The resistance of the regulator varies in accordance with the load resulting in a constant output voltage. The regulating device is made to act like a variable resistor, continuously adjusting a voltage divider network to maintain a constant output voltage, and continually dissipating the difference between the input and regulated voltages as waste heat. By contrast, a switching regulator uses an active device that switches on and off to maintain an average value of output. Because the regulated voltage of a linear regulator must always be lower than input voltage, efficiency is limited and the input voltage must be high enough to always allow the active device to drop some voltage.

Linear regulators may place the regulating device between the source and the regulated load ( a series regulator), or may place the regulating device in parallel with the load (shunt regulator). Simple linear regulators may only contain a Zener diode and a series resistor; more complicated regulators include separate stages of voltage reference, error amplifier and power pass element. Because a linear voltage regulator is a common element of many devices, integrated circuit regulators are very common; linear regulators may also be made up of assemblies of discrete solid-state or vacuum tube components.

https://en.wikipedia.org/wiki/Linear_regulator

What I used for my custom PSU is a relatively new devices, which is rated by audiophiles to achieve similar measures to a battery, amazing. Isn’t it? I’m talking of the LT3080. What we’re gonna do is basically find a suitable transformer to get an AC voltage of, let’s say, 12 volts. Then, use a single resistor or a trimmer to set the desired output voltage. It took me some hours to get it finished, but I’m pretty pleased with the result. Here is the application diagram:

This is how I built mine:

From the top. Notice that is very compact in size, and doesn’t need any heatsink.

Bottom view, pretty simple layout…

Testing it. On an incredibly tidy desktop.

Boxed, the final size is about the same as the Pi. Nice work indeed.

This PSU will cost you around 30 euro plus some labor hour. As I said before, this is quite a good result, and I had lot of fun doing it. But, if I would have knew… I’ve choosen the next method… You’ll see why. In the end, as I told you, I do want the best raspberry Pi power supply available…

The sunday Diyer option

Lately I found several chinese ebay stores, and with them came my personal gizmo heaven. Not my pocket’s one. I found a perfect solution for powering a raspberry Pi, a DAC, a transport and even an hard drive, if you need it. This is the optimal solution, since you get 4 different voltages, to power up 4 different devices. Here, you can really squeeze out all the quality of your little Pi, powered with RaspyFi obviously… What are we talkin about?

Here it is, in a tiny board we have 4 ultra low ripple TPS7A4700 voltage regulators. Which has pretty impressive specs. You can choose to have 5 Vdc or 3,3 DC. So you can directly feed your Dac or your transport. Add to this 2 2×6 10vA power transformers or find 2 in your house… these listed are just enogh with 800 Ma, if you wish to have confortable amount of current just go with 2 toroids. Then box it, with your Pi, your dac and everything you want. I can say my personal quest for the best raspberry pi power supply has finally come to an end…
I just ordered this, I think it will beat all these fancy USB PSUs sold for 200 euros… iUSB reminds you something?

This is the link where you can buy this amazing PSU. I ordered mine today, and sincererly can’t wait till it comes. I know in the end it doesn’t come cheap, I guess it will cost more than 100 euro when finished. But I’m not gonna worry no more about the quality of my PSU. In the end, I’m having 4 different PSU’s of exceptional quality. And I think I’ll get lot of audible benefits… I will use it to power up my Pi, my XMOS2 + SABRE 9023 DAC (the DAC and XMOS will have different power rails… bye bye USB crappy DC). And I’ll have one remaining hi-quality 5v rail. I could use it for an headphone amp, for example. All in the same box. Guess this is the final piece of my Reference Audio Server, powered by RaspyFi. Guess this could put into shame hi-end devices…

And you, guys? What is your idea for the best raspberry Pi power supply?

Pubblicato in Diy

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Superkikim

Please, resize your pictures …. 2592 × 1944 pixel ?!? Took for ever to
load the 1st pic of your article … ok, my connection is slow, I
admit. but anyway
Mateus Machado

Thanks you for this. It’s very valuable.
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nsayer

At the risk of spamming… I’ve created a thing I call “Pi Power.” It’s a daugherboard for the Pi that sits on the GPIO connector (it has a stacking header so you can piggyback something else) and has a 2.1mm barrel connector that can accept 6-15 VDC in and supplies 2A @ 5V out. It’s available on the Raspberry Pi market in Tindie.
CmdrAdobo

How about normal powerbank as a source? Is it clean source?
Pingback: A DIY Power Supply For Hi-Fi USB Audio With Your Raspberry Pi | Jarret's Personal Blog
TioFrancotirador

This guy makes fantastic PSUs for different DACs: http://www.tomanek.dbv.pl . I have “ULPS mini” for my setup: Raspberry Pi + Schitt Modi DAC.
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Tara

Would love to share this raspberry Pi power supply – http://www.SmartPowerBase.com
Jonas

I have a question regarding your ‘full DIY’ apprach. I’m looking to add a raspyFi to an ODAC/O2 and since I already have 16VAC in the box it seems to be a perfect match.

However, I don’t fully understand your implementation. In addition to the input and output capacitors you seem to use two small caps? Is one parallel with the poti – I think I saw that in the manual. But what about the second one?

Thanks for a great project. Any help is appreciated.

Jonas
Daniel

I had a look on 3 different power supplies with the oscilloscope:

http://www.crazy-audio.com/2013/09/raspberry-pi-power-supply-noise-on-the-5v-rails/
olivier

I ask diyinhk quality of this card compared to a salas regshunt,he said that the possibility of this card are endless,!!I expected a different answer.
the question is posed, someone in this experiment,
nexzzt

Would something like this be any good? Thanks

http://www.ebay.com/itm/1-5V-40V-5A-adjustable-regulated-Linear-Power-supply-Transform-Board-/400553991428?pt=US_Amplifier_Parts_Components&hash=item5d42e0dd04#shId
Nattydraddy

Quote: ” What is your idea for the best raspberry Pi power supply?”

The Gigabyte G1.Sniper B5, Intel B85 Mainboard for a x86 cpu. It has a “Noise-less USB DAC-UP port” and cost less than one of “these fancy USB PSUs”. Beside that , the x86 computer also works as a file/music server for the RPi.
RoboJ1M

I built a DC-DC PSU built to clean up dirty DC from a car or boat (boat specifically)

On recommendation from the RPi forums I tried a 5V switching buck UBEC from Turnigy.

Dead cheap because it’s RC model kit, also needs to provide highly stable V because expensive flying models need clean 5VDC for all the RC gear on board.

Here’s pics:

http://instagram.com/p/c4ahl1HIgb/
http://instagram.com/p/c4_ts2nIq4/
http://instagram.com/p/dNnFSKnIv6/
http://instagram.com/p/eIoAkxHIn3/

With no load the voltage was 5.28V, dropped 0.03V drawing 2A (assumed, just by adding up the max draw of what was connected, no facility to connect an ammeter)

Ultimately I used it to power a 7 port hub, ran it for a week with the following hanging off of it:

1) Model B RPi
2) 2.5″ 500GB HDD (no external power)
3) Atheros AR9271 based wifi stick

4) Huawei E3131 3G stick (highly recommended)
5) Flash storage stick
6) Charge phone
7) Charge phone

Few glitches, reboot always solved them, no idea if it was power related:

1) Sometimes the 3G stick would disappear. Reboot solved it
2) Sometimes the UPnP renderer (gmediarenderer) would crash. Reboot solved it

Obviously it’s DC-DC not AC-DC but I’ve got buckets of AC/DC bricks lying about (I think they’re breeding), I can just plug it into a >=5.5V one of those.

Need to make something to allow me to measure the current but I’m happy it’s pretty damn stable, even when we had all 7 ports populated with the potential to pull 4.7A, which is way above it’s rated output but below it’s peak pull.
Gitaarwerk

I would love to know if there are any good PSU to get this thing working better than USB powered? The thing is.. I really do not like to mess around with transformers (also block transformers make a noise which I really do not like at all. And all block transformers I do hear ). I wouldn’t mind a less good option, but preferable affordable. Perhaps it is a good idea to make a list with suitable adapters who cost less? so like a cheap-but-ok solution, medium and best? So there’s someting for the beginner, medior and enthusiast class equiment requirements
- RoboJ1M
  
  Have a look at my reply further up.
  I built a DC-DC PSU using cheap off the shelf R/C plane bits which I can then run off of any old AC/DC unit that provides >=5.5VDC. I was build to use car/boat alternators as the supply but I use a 12V AC/DC brick indoors for development. No transformers (directly) involved.
  - Giaarwerk
    
    I unfortunately ave nothing like that lying around here
    
    I’ve begun some more questing, and I think the suggested PSU is quite a nice one. Especially since I DO- want to power a JD Labs CmoyBB at > 9V..
    
    My friend is an engineer, and he understand these things. He said that there’s not an extra transformer needed (we use 230V @ 50Hz in holland). But in the article above, there is mentioned that we need 2 trafos for it. Am I missing something? In the end, I’ll be fine with the price. I will add an extra output/switch to send signal to my amp. It’s funny, that the RPi is the cheapest thing, and the PSU will be the most expensive part
TheOldMan

How about one of these: http://www.plccenter.com/Buy/ARTESYN%20TECHNOLOGIES/NLP407605J. Get the NSFP ones for $25: 5V @ 8A. You can even get a “free” one by keeping an eye out for broken Dell or Netgear network switches as these often have 5V 4-8A PSU. If the PSU is what caused the switch to be tossed, typically it’s just an $.80 capacitor that needs to be replaced.
- mikelangeloz
  
  Good finding, mate. Guess for those that are more diy oriented, this is a good solution. Haven’t you tried it yet? The only concern is that it should output a stable voltage , ranging between 4,75 and 5,25 vdc
  - TheOldMan
    
    I was going to use it for the RPi but figured it was overkill. So I used it to make a fast USB charger for all the Kindles, Android phones, toy helicopters, etc… in the house. I wired several USB outlets to it in a box and I can charge multiple devices at one time. Since this PSU is used in network switches, I presume that it puts out a stable voltage, especially since it has 8A of headroom.
    For the RPi I use a Motorola 800mA charger and have never had a problem with audio. The only devices plugged into the RPi are an ethernet cable and a 32GB USB thumbdrive that holds all of my music.
    - mikelangeloz
      
      Good move you oldman! Mobile charger are a perfect fit for the pi, btw
1000io

Ok, and what go you think about use a SAI?
- mikelangeloz
  
  What is a SAI?
Håkan Berg

Will the TPS7A4700 regulator board really drive the Sabre DAC? The specs I’ve found on the DAC states it requires 6~20V, and this board only supply 3.3 or 5V.
I know the regulator itself can deliver much more, but not in this configuration afaik…
- mikelangeloz
  
  2 options:
  
  First as Derek said:
  
  Have only looked quickly at the TPS7A spec but I believe you could ground pin 4 of the TPS7A (probably easiest to go to the center pin of the output jumper) and, with the jumper in the 5V position this should give you 11.4VDC out – enough for the DAC.
  
  Mine: inject the dc after the onboard reg of the DAC.
  What do you think?
  - Heffa
    
    Oh, I missed that you are going to mod the regulator board – then it should work I think.
    However, if I may suggest an alternative you could get a couple of TPS7A4700 Evaluation Modules directly from Texas Instruments for just $20 each. Here you can set the output voltage in 100mV intervals using simple jumpers. The downside might be that it requires DC in, but it shouldn’t matter that much I suppose.
    I think I’ll try one of these boards first, before getting the diyinhk-board and start modding it.
    
    Sometimes I wish I didn’t build my sigma11 for 24V output, it could have been useful here as well as for my PPA headphone amp
  - Heffa
    
    Forgot to add the link to the TPS7A4700 Evaluation Module :
    
    http://www.ti.com/tool/tps7a4700evm-094
  - Derek
    
    Tread carefully – according to the DAC supplier you will need to change a SMD resistor if injecting 3.3V from the DIYINHK board. The DAC is looking for 3.6V. See further down this page.
- Derek
  
  You can use two rails of the TPSA4700 board connected in series to drive the DAC. Gives 10.07V.
francescop

Hi,

I would like to try my hand at the “Full DIY” approach as per your suggestion (having recently started DIYing I fancy a new challenge, and this would be the first time that I build something which did not come in a kit with a PCB).
Would you be so kind as to list the specifications for the components which you have used? I am still not well versed enough to work this out based on your application diagram.
Many thanks in advance!
Francesco
- mikelangeloz
  
  Hi Francesco,
  
  I just followed the datasheet you can find here:
  
  http://cds.linear.com/docs/en/datasheet/3080fc.pdf
  
  I used only electrolitics caps, the big one is a jantzen cross cap, I used this only because it was what I had… As for the resistor, you should calculate it against the imput voltage…
  If you need more help let me know!
Derek

Ouch! The seller, DIYINHK, seems to have gotten greedy as a result of all of us Raspyfiers buying this power supply. When I bought mine it cost U$98.95 plus U$8 shipping. The shipping cost is now U$40!!!

Likewise the XMOS receiver board was U$59.95 plus U$4 shipping. That’s now also U$40 to ship international.

Funny how they can ship one day for <$10 then, as soon as demand goes up its more expensive to ship! Speaks volumes…..
- Derek
  
  As reported elsewhere on RaspyFi it is possible to get these items with a cheaper shipping cost if you visit DIYINHK’s online shop. Apparently eBay rules have changed and resulted in the raised shipping costs. Apparently.
francis

Hello, I decided to order this psu from diyinhk…. and now I wondering the following:

- what other stuff I would need to put between the psu and my current wall plug ???
- From the PSU to the pi, if I cut an micro USB cable I see 4 small cables (brown, green , white and orange) … hum if there is a good way to connect this cables ?

If anybody could share a drawing with the different parts for using this PSU, it would be very helpful

Francis
- mikelangeloz
  
  Hi Francis,
  
  you just need two trasfos. They will supply ac into the PSU. My idea is to use 2×8 trasfos. You can find a suitable one here:
  
  http://it.rs-online.com/web/p/trasformatori-toroidali/6718912/
  
  If your wall socket is at 230v… Or you can choose something like this:
  
  http://www.ebay.com/itm/Encapsulated-Mains-Insulated-PCB-Power-Transformers-230-6-9-12-15-18-24-VAC-V-AC-/180843068279?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item2a1b163b77
  
  There are double secondary trasfos, but they are rated at 530 mA, which may be too short… Tell me where are you from, I can be more precise.
  
  As for connecting, see here:
  
  https://en.wikipedia.org/wiki/Universal_Serial_Bus
  
  You only have to connect the orange cable to the + of the PSU. And leave the others cables intact.
  - Francis
    
    Hi, thanks for replying. I live in switzerland and the wall socket deliver 230v at 50hz.
    
    My understanding is that I need, for each of the PSU, “a piece” that convert the wall socket ?
    
    what would you advice in term of transformer type and amperage output, knowing that my plan would be to use the PSU for powering 2xraspberry PI (yes 2 pi), the XMOS USB to i2s and the DAC SABRE.
    
    1) Camdenboss Transformer (http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=360622935292) <- this is what you suggested in your article above?
    
    2) toroidal transformers (link from rd-online)
    
    3) or these Encapsulated Mains Insulated PCB Power Transformaters
    
    ok all of them are transformers at the end …
    
    Francis
    - mikelangeloz
      
      If these are your requirements then I’ll choose at least a 1a per secondary…
      So neither the camdenboss trasformers and the other ones are good enough for you. As you wrote me, a good solution would be a custom made trasformer 4×6 or more (better 4×8). How much are they gonna charge you for this?
  - RW
    
    Hi, very interesting build!
    
    Just ordered this 4x1A PSU from diyinhk. I also have a newbie question regarding the additionally required toroidal transformers that power the PSU board.
    
    The diyinhk PSU board has the input voltage range printed, which says 6-8V.
    
    You suggest a 2x8V toroid above, but the one you link to outputs 2x9V. Is that on purpose or would the 6V version be a better fit?
    
    For example: http://it.rs-online.com/web/p/toroidal-transformers/6718937/
    
    This 2x6V toroid outputs 2.5A. Is guess you need a total of 2 of these toroid transformers (2x 2x6V) to power 4 separate inputs on the PSU board? This would mean 1.25A per line, which is probably enough for most equipment (e.g. an separately powered hard disk), right?
    
    Keep up the good work!
birca1987

mikelangeloz

Did you get your psu from diyinhk, any improvement?
- mikelangeloz
  
  No, not yet… I’ll let you know…
Azi_muth

Mike did you check sigma 11 regulated power supply from amb lab http://www.amb.org/audio/sigma11/?
It has 4 outputs and seems quite cheap to build.
Bob

Did you try to use the i2s from the P5 connector of the PI? I have a mini2496 DAC and I’ve replaced about everything inside. Now I’m using the spdif from an m-audio card (dac has only spdif input) but I was hoping to try the i2s method. Since I already have the PI I wouldn’t shell out another 100$ for and xmos. I also have a ta2020 that I’m using with a meanwell smps supply. Now you got me thinking on that supply…
- mikelangeloz
  
  Yeah, there are gpio for the i2s, but you need to solder some pins on the P5… I’ll document it soon!
  - Bob
    
    I’d loose my warranty over this mod for my DAC Just need to be sure that it’s worth it. I’ll wait for updates and thank you!
  - Bob
    
    Hi, any update on the i2s?
Ven

Would something like this work?
http://www.ebay.com/itm/Logitech-Squeezebox-Touch-Upgraded-Power-Supply-5Vdc-3A-/281071744127#ht_1171wt_758
- mikelangeloz
  
  Yes, It should… But you should change the power connector.. .And it’s quite expensive too…
Derek

Ah, the sight of a DIY workbench! Warms the heart. Very interesting PS options. I looked at that board with lust when I ordered my DAC/XMOS board. Christmas ain’t far away! Meanwhile, I built this http://elinux.org/RPi_5V_PSU_construction – point-to-point wiring, mounted on a Perspex board with xmfr and it definitely improved the sound. I chickened out at going to 5.25V and settled on a 548-ohm resistor for R1 which gives 5.18V with no load and 5.12V with the Raspi playing. I also built a simpler linear PS and use it to inject 5V into a shortened USB cable to drive my UDAC-2. Eliminates the crappy DC from the Raspi’s USB port. Worthwhile improvement there as well. Have ordered some USB connectors (the joys of those Chinese eBay shops) and some pure silver and pure copper cryo-treated Litz cable to make my own USB cables.

Onward, Mikelangelo….

Derek
- mikelangeloz
  
  Hi Derek, happy to know whe share the same passion! Consider that desktop serves me for lot of duties… Studying, soldering, browsing and sometimes has my gf on it…
  Yeah, I saw this PSU and it’s a good option indeed, just started to look for something different from 78s…
  The joys of Diy… Could you please post the links for the usb connectors and the litz cable?
  See you soon Derek!
  - Derek
    
    There’s space for your gf on that workbench…nah…!!!
    
    The litz cable came from these guys http://www.ebay.com/itm/26-AWG-7N-CRYO-TREATED-UP-OCC-SILVER-1-GOLD-TYPE-2-LITZ-STYLE-WIRE-PER-FT-/271214876933?pt=LH_DefaultDomain_0&hash=item3f25aa9905
    
    Good guys, prompt shipping and refunded the ‘double shipping’ if you order two different items like I did. Other item from them was copper litz: http://www.ebay.com/itm/26-AWG-7N-PURE-CRYO-TREATED-UP-OCC-COPPER-TYPE-2-LITZ-CUSTOM-WIRE-PER-FEET-pS-/271225590244?pt=LH_DefaultDomain_0&hash=item3f264e11e4
    
    The USB A and B connectors were from: http://www.ebay.com/itm/10Pcs-USB-Type-A-4-Pin-Male-Three-Types-Plug-Connector-For-PC-DIY-/170844394272?pt=LH_DefaultDomain_0&hash=item27c71e9320 and http://www.ebay.com/itm/5-Pcs-USB-Type-B-Male-Plug-Connector-Socket-For-DIY-/181067529032?pt=LH_DefaultDomain_0&hash=item2a28773b48
    
    Also, you might want to look at these toroids for your Texas Instruments power supply board: http://www.ebay.com/itm/MCTA015-06-Multicomp-Transformer-15Va-2-X-6V-/140941919281?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20d0cb0431
    
    Not cheap, but they are 1.25A on each secondary out – nice to have the extra current. And they’re from the U.K so should get to you before the 4-rail board!!
    
    By the way, did you ever get my responses to your email?
    - mikelangeloz
      
      Yes, sorry for not replying… Having lots of emails lately… But your feedbacks are very important for me! Thanks for the links…
      - Derek
        
        So you’re going to get out the VERY small soldering iron and modify one of the rails on the PS board? What’s your approach – ground pin 4?
      - mikelangeloz
        
        Sorry Derek, can’t get what you mean…
      - Derek
        
        The TPS7A board has four rails of 5V out. Your ESS DAC requires 6-20VDC to power it. So you need to modify the output voltage of one of the rails. Have only looked quickly at the TPS7A spec but I believe you could ground pin 4 of the TPS7A (probably easiest to go to the center pin of the output jumper) and, with the jumper in the 5V position this should give you 11.4VDC out – enough for the DAC.
      - mikelangeloz
        
        I thought to bypass the onboard reg of the DAC, but I think yours could be a valid solution as well, but if I use 8 v ac trasfo I think values could be a little different… So maybe I could change the resistor values… What do you think?
      - Derek
        
        You’d need at least a 12VAC xfmr in – providing the rectifier on the board can handle it, which it should. Might be an idea to contact DIYINHK and ask their opinion. Check the rectifier model online for its specs when you get it. From the last picture it looks like the PCB may have holes for the different value pins – if you’re lucky! Then it’d be straightforward.
      - mikelangeloz
        
        Yeah, I’ll contact them. As I told you before, I thought to bypass the DAC onboard reg, having 2 in series doesn’t appeal so much to me… What you think about it? May it degrade the 2 regs overall performance?
      - Derek
        
        What’s the output voltage of the DAC’s onboard regulator? Probably 5V if it requires at least 6V in. If the DAC is indeed a 5V device then you have options. You could mod the PS as above and run 2 stages of regulation or you could follow your original idea and bypass the DAC’s regulator. Suspect the 5V from the TI PS might be cleaner than the onboard DAC regulator. Probably the ideal way is to mod one rail of the PS and bypass the DAC’s regulator such that you can power it both ways and let your ears decide which is best.
      - Derek
        
        Where on the DAC did you plan to inject the power from the TPS PS? Haven’t got mine yet so can only look at the photos.
      - mikelangeloz
        
        Just after the reg, it seems the only point available for safe soldering…
      - Derek
        
        Before or after the output filter caps? And you planned to cut/lift the output leg of the reg?
      - mikelangeloz
        
        Derek, I’m investigating, but I think before the filter caps (but gonna check this) and I think I’ll lift the whole reg…
        I’ll ask to the DAC producer what he thinks about it….
      - Derek
        
        Let me know what they say, please. Don’t forget the ESS 9023 is 3.3/3.6V in so set the PS output jumper appropriately! Think we were talking 5V above, which is wrong.
        
        I realized this when I stumbled on: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390616438553
        
        Think your DAC (and mine when it arrives; got the XMOS board today and already removed the ferrite bead to inject power at CN1) looks better built but this neatly solves the power issue if you have the 4-rail PS. And it seems to have the virtue of simplicity.
        
        Finally, for anyone considering the XMOS board and wanting to mod it to bypass the Raspi’s noisy USB power but unsure of soldering SMDs, you can easily modify an existing USB cable to inject a linear 5V to power the XMOS board via it’s USB receptacle. Leaves the XMOS board unmolested but achieves the same thing as an external PS. And a shorter USB cable.
      - mikelangeloz
        
        Yeah I thought we were talking of the 3.3v rail… And the idea of the calbe is the simplest, but I’d prefer not to let the 5v travel near the signal…
      - Derek
        
        Agreed. That’s my approach as well – straight into the XMOS board. Suspect that if you do away completely with a positive cable in the USB cable coming from the Raspi you would not even need to remove the ferrite bead at FB1.
      - Derek
        
        Had to contact the DAC provider in Seoul re a shipping issue and took the opportunity to ask about injecting the external 3.3V from the TI PS board. He responded immediately, sending the attached image indicating the injection point and said to change R10 to a 220K value as the onboard reg was a 3.6V output. He also promptly checked my shipping issue and replied within 12 hours! A good guy, highly recommend him.
      - Derek
        
        Sorry, didn’t realize how horrible the eBay html image was. This may be better.
      - mikelangeloz
        
        Yeah this chap is very prepared and gentle… Let me know when it arrives!
Martin Pascoe

Do you really think that your $100 buys you a significant difference over something based on the LM317′s?

I am using one of these to power a TA2020 amp and I can’t notice any PSU related issues at all…
http://www.ebay.com.au/itm/5-Amps-Voltage-Regulator-Module-Out-1-5-to-32VDC-/130579787647?pt=LH_DefaultDomain_0&hash=item1e67296f7f&_uhb=1
- mikelangeloz
  
  Hi Martin,
  the PSU you posted is quite interesting, for people interested in having only 1 voltage rail. I owned several tripath based amplifiers, and I know how a proper linear PSU may benefit them. And this quite fits the needs…
  As for your answer, I do believe that the PSU is the most critical part of an Audio system (NVA apart…) and so most of the times it could end as the most expensive part of a Device.
  Then you should consider that 100$ will buy you 4 PSUs, which di per se is something significant…. If you multiply 20$ x 4 you get 80$ which is not that far… But, as I stated in the arcticle, this makes sense when you build a system and you do care about feeding with different voltages and rails different devices. So, in my case, Pi, XMOS Transport, DAC and I still have a free Rail…
  
  I can tell you BTW that, the LT3080 clearly overperformed while powering my DAC. It has less noise, even if it reject less ripple than the LM.
  So, if you plan to have different things to power on (as me) you should comfortably go with the 100 $ PSU. If you just don’t mind having different power rails you are ok with the one you posted.
  Btw, have you modded you 2020? I used to love this tiny amp… I changed a lot of stuff on it…
  - Martin Pascoe
    
    That’s true, 4 of those baords can add up to a bit, but I chose that for a particular task and it works exceptionally well, I can see a need for multiple rails but for a Pi and DAC a single PSU with suffiecient current (and let’s face it 3amps out of an LM317 is more than sufficient) will be just fine.
    There are many other LM based kits available for less than $10, I chose that because of it’s nice layout, big heatsink, big rail caps etc, may not be perfect but it does a comendable job for the money.
    
    I have done a few mods to the TA2020, but I started with an Arjen Helder board and they are pretty good to begin with, added the linear supply (instead of the SMPS people are obsessed with) and it really sings.
    - mikelangeloz
      
      UUUUUh you got also a display attached to the PI! Do you mind to tell me how you got it working? I’m so focused on developing RaspyFi’s core, so I will be more than happy to follow your path.
      Also, i just want to point out that having more rails is not for having more current, as you say there are many reg that will output more than 1 amp. But to insulate each device in the system, and avoiding them to be polluted by the others. I can assure you this makes lot of difference. If you consider, for example, that Hi-end cd players has different PSUs for each component….
      You’ve done a pretty good job with your 2020 amp! If I may suggest (I know arjen products and how they perform, very good indeed) I will change the input caps, with mundorf black cross cap, they are cheap and they sound pretty good…
      I look forward to hear what you did with the lcd display!
      and, btw, thanks for your contribution. I like to talk with passionate and clever people.
      - Martin Pascoe
        
        For the LCD I used the below wiring diagram, I want to replace it with a 4×40 version to fit more info on the screen:
        
        http://my-raspberrypi.de/wp-content/uploads/2012/11/raspberry-lcd.png
        
        The code running the display is just python with the help of the RPi.GPIO library, it’s still a work in progress, occasionally (once every 300-400 songs) throws an exception and needs to be restarted, I’ve haven’t yet had time to debug further what is going on but I’m trying to make it as robust as possible so it can be left on it’s own and not need manual restarting if it stops working, I also want to add some extra features like a rotary encoder for volume control, and a few buttons for track control.
        
        I fully understood why you wanted multiple rails…
        
        The supply I chose was to power a TA2020 so needed big rail caps and a high current rectifier, you could get away with something smaller with just as good results like these (and at half the price):
        
        http://www.ebay.com.au/itm/Voltage-Regulator-Kit-AC-DC-in-DC-out-Based-on-LM317-/260479385900?pt=US_Pro_Audio_Parts_Accessories&hash=item3ca5c8012c&_uhb=1
        
        Here’s some more pics of my setup:
        http://db.tt/SgRHcOYH
        http://db.tt/RZRI9ZBk
        http://db.tt/0P681him
      - mikelangeloz
        
        You made a pretty good work with your 2020 amp! Are you using with a pre or not?
        Also, did you try to bypass the big caps with 1uF ones or something? They improves a lot PSUs performance on transients…
        Then, for the display, I looked a little, which one do you think suits the most:
        
        http://www.ebay.com.au/itm/Module-Ecran-LCD-Bleu-2-16-2×16-Screen-HD44780-Arduino-Raspberry-Pi-5V-/271090369738?pt=LH_DefaultDomain_23&hash=item3f1e3ec4ca&_uhb=1
        
        http://www.ebay.com.au/itm/Module-Ecran-LCD-Bleu-4-20-4×20-Screen-HD44780-Arduino-Raspberry-Pi-5V-/271221485589?pt=LH_DefaultDomain_23&hash=item3f260f7015&_uhb=1
        
        http://www.ebay.com.au/itm/1602-character-LCD-display-module-SPI-interface-for-Arduino-AVR-PIC-Raspberry-Pi-/160831609856?pt=LH_DefaultDomain_0&hash=item25724f9c00&_uhb=1
        
        This has also buttons:
        
        http://www.ebay.com.au/itm/RPI-UI-User-Interface-for-Raspberry-pi-with-blue-16×2-LCD-buttons-temp-on-I2C-/160966428877?pt=LH_DefaultDomain_0&hash=item257a58c8cd&_uhb=1
        
        What do you think in integrating your code in a future raspyfi release? Could be a nice add for users to attach a lcd in a simil-plug & play way…
      - Gheorghe Birca
        
        I use this tutorial for my audio project wich will include 20*4 lcd display and 5 buttons. http://bobrathbone.com/raspberrypi_radio.htm and waiting for one of this enclosures for my project http://www.ebay.com/itm/S-2207-Aluminum-enclosure-DAC-case-amplifier-chassis-DIY-BOX-/111066776972?pt=US_Amplifier_Parts_Components&hash=item19dc18858c
      - Martin Pascoe
        
        The PSU already has bypass caps, but they’re behind the big arse electrolytics so you can’t see them in the pics.
        
        Any of those LCD’s would do, as long as it’s HD44780 or compatible it should be good.
        
        The last one with the buttons… I’d rather go with the Adafruit one for the same money:
        http://www.adafruit.com/products/1110
        
        There’s a few variations on LCD types available including that nice RGB backlight model.
        
        Personally I’d be going with the 20×4 (or as I’m about to do 40×4), you can’t fit much info on the screen of a 16×2.
        
        If your interested I could probably do you a fly lead to connect your LCD like I did for mine.
        
        Nice offer to include the code, but it’s a long way from complete, until it’s rock solid and never throws exceptions I don’t think it’d be good to share.
Gordon

Going to use one of these : http://www.audio-gd.com/Pro/diy/PSU09/PSU09EN.htm
- mikelangeloz
  
  Hi Gordon, do you know which regulator they use?
  - Gordon
    
    Hi Mike , I don’t know which reg they use . Kingwa of A-gd told me that the PSU09 is not suitable for the 3.3v my Amanero usb-i2s.However if you want to use the board to supply the dac board they can supply it with one of their good quality R-cores for about $50 us.
    
    Gordon
Gyp

I’m going to have to read through this and try and fully understand it.

In the mean time I was looking at this:-

http://cpc.farnell.com/1/1/84868-ac-dc-linear-psu-5v-1a-2-1mm-t2526st-stontronics.html

Not very sexy, but it is a linear 5V 1A for about 15 Euros.

But I need to get a working Raspyfi first before I start fiddling with the power supply

Currently using the RS Components supplied 5V 1.A switched mode PSU; not idea but should be enough to run the Pi + bluetooth + Hiface 2
- mikelangeloz
  
  Hi gyp, I advise you this is linear but not regulated, so you could end up with voltage oscillations which may not be good for the Pi. Probably you should stay on your PSU instead…
  I think I found the solution for your issue, write me an email with your problems, we’ll get it sorted!
  - Martin Pascoe
    
    According to the datasheet on the farnell site they are indeed regulated. The quality of the regulation may be questionable but it is still regulated.
    - mikelangeloz
      
      Yeah, you’re right… Just looked only to the description… As for the regulation, probably there’s only a capacitor…
      Sorry for the mistake