Linear PSU DIY

Hi all,

I know a little bit of electronics and have seen many awesome projects, but have never created my own… why? Well I have no clue where to start when it comes to PSU units. Sure I can buy a preconstructed linear PSU, linear because I keep hearing those produce less noise. I still need many hours to train my hearing, so I have trouble hearing the difference at some points… Back to topic, a preconstructed PSU gives you a little less freedom in your design, plus they can be quite expensive.

Then it hit me! The Volumio forum has many like minded audio lovers and they might (want to) point me in the right direction… :unamused: right?

So the basics first, we’re going to need a (ring) transformer to transform 230V to ca. 15V, then we need to fuse and rectify it (AC > DC). Now we have around 15V DC, we can tone it down to 5V using a (heat sinked) regulator, after which we can filter some more using appropriate capacitors (Panasonic/Nichicon) and maybe some resistors.

So far so good, I can understand the needed components, but how do we go about calculating the values actually needed and why does it affect the sound really?

For example, I’ve seen some people use the NT-25HQ PSU. Looking at the picture it doesn’t look like a difficult design. Hence my question here, it looks relatively simple to make your own linear PSU.

Well if I have so much info already, what do I need?

I’d like to be able to determine what components work good together so that I can create my own PSU to fit in a case. This gives the creator virtually limitless flexibility in making new nice audiophile projects. :slight_smile:

So I’m looking for info like this:

  1. What transformators are best to use; I see alot of Talema’s, are those OK and they state 115V input, how does that work with 230V (Europe)?
  2. What rectifiers are advised?
  3. There are lots of regulators out there, is there a noticeable difference? For example is the LT323AT any good and why so?
  4. Where do the capacitors come in and which ones are low noise? Also the uF values are kind of new to me, can I calculate this? E.g. I read somewhere the UPW1C103MHD (10000uF low ESR 16V) were pretty good, but I have no clue why.

Maybe I’m asking too many questions, but I thought I’d give it a try, since I really wanted to do my own project one day. I already found some amp boards (TPA3118) and am close to a tube pre-amp (with VU meters; for example a 6N3 variant), so the PSU is biggest challenge by far.

Thanks in advance.

Interesting post, which I’ll certainly keep my eye on. Sorry I don’t have any expertise to contribute.

I am not a real electronics guy so no first hand experience (yet) from my side, but take a look at

I found this some time ago when I was looking for possible PSU’s and as they offer a DIY kit with all matched components, you still have a lot of freedom in actually building it. Not sure if it gives you enough freedom :slight_smile:

Verzonden vanaf mijn iPhone met Tapatalk

This actually opens doors indeed. Still I want to know why these components were chosen :unamused: just to understand the designs… But this helps for sure and the pricing is right too, great find!

Here is a great post on the subject:

This is a great RPi/DAC power supply board, with lots of information on it’s design and configuration, with a fair bit of DIY builder feedback.

There are reasonable Chinese clones available on ebay.

Hey, thanks for reposting!
Saiyato, on our site we have some links to references about regulator design where you can find more knowledge about actual values of components.
With linear regulators it’s pretty much straight forward - they start at the regulators spec sheet (e.g. LM317) and get minor mods in a precise application (e.g. 5V close to everythin). Regarding the PSU (transformer and main cap) there is a link to a calculator for CRC konfigurations.

PS: let me know if you have questions and I will try adding information to our site

Maybe I moved away from the subject of the post … but I found this:

It seems ideal for powering our devices.
Anyone have experience with these devices? I can not find any practical diagram.

Thanks for the feedback all, will investigate the options! I see I have some reading to do :wink:

This and my PSU. 3A are enough for DAC + OLEDDisplay and RasberryPi3. In my case the DAC (sabre audiophomics) is powered directly by the Rpi and has a further linear regulator on board. 6.5 V is necessary for dropout.