Hi Antony!! good to see you here!! if nothing blows up , we got a lot of listening to do this weekend!!

Well it all depends... you can do it very cheap but not as efficient... meaning build a LM317 supply yourself and add a cheap 50VA transformer, in any cheap case, canibalize an existing usb cable... this will be in the region of 40euros

If you want a nice case and Salas supply, high quality transormer, with "audiophile" capacitors, nice cable (Mogami), nice usb neutrik socket, ferrite rings all over, emi/rfi filter, etc it will be in the region of 150euro...

I have not heard the Salas version (if all goes well, i will have mine built in the weekend), but it is said that it makes a very audible improvement over simple supplies...

I have heard this in various Bufallo dacs... the best ones had Salas and massive transformers.

I do not know if galvanic isolation will improve things... this is also to be added to the cost should you wish to implement it as well.

The "cheaper" LM317 method is also universal i must add, because it does not take in account current and consumption so you can use it with any usb device, the Salas is only implemented for the specific circuit and it may not easily be used on another with other current/wattage as efficiently... this is  also something to take into consideration... 

I am very confident to say though, that in the budget dac arena this is something really good and it would be really worthwhile to give it a test, in this forum.

Very true...

Also reminds me of this...

Very nice work!

Thank you LFF!!

@fishki13 It will be interesting to see how the isolator performs. On the transformer i would like to suggest you go for a larger one.

I have tried with one like you say (on lm317) and the comparison with the 50VA toroidal was definitely audible.

This picture is with the first attempt with small trafo (9V/10VA) and lm317



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Next i went for large trafo and lm317



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And finally i went for the Salas shunt as shown in the previous post.

There were always differences to the better.

I am sorry i haven't made the component chart yet, and i haven't tested on ociloscope... when i have the time i will post the results.

PC side, signal +/- pass thru, Earth negative, red positive is cut...-

PSU-

ODAC side receives signal +/- pass thru, Earth from PC and PSU and positive ONLY from PSU

In other words USB negative/earth is common for all, positive power from PSU only going to ODAC, signal uncut passes thru.

You may want floating earth on psu side not common with Mains In, or you can try common ground... floating is best for isolation.

I am not familiar sorry, with o11 what is it?

The Transformers i like to use is larger than you want because they have electrical inertia and is less prone to mains fluctuation instability...

The ODAC power consumtion is 52mA as measured by a friend of mine, but i use large trafo, it is over engineering, i know... but i have heard the difference... in the three versions i built.

I think information on this matter is important to be public, since i do not know of any other site going into this kind of detail... (except my home forum avclub.gr but in Greek only)