L-Adapter

[thimios]

It doesn't need to be an automated heavy duty lab box when for once in a while few Watt use. Bench E-Loads can cost from hundreds to thousands. There are simple gadget board ones too.

I think that is an Elektor published power supply that function as electronic load too.
Sure i don't speak for an expensive commercial one.

 

[Salas]

Something like this one in the video looks doable as well : DIY Adjustable Analog DC Electronic Load

 

[didiet78]

Finished my Dual AK4490 Dac. Heatsink almost hot, i thing input supply too high 12vac. But overall it good. Thanks Salas

 

[Salas]

Everything hand made. Congratulations.

 

[Jason Hubbard]

Is it possible to parallel Q2?

If I want more current capability how do I parallel Q2 to do that?

 

[Salas]

Never done it during its development, maybe possible. Simply parallel yet another Q2 I would think. The simulator says its OK at least, if of any practical value. Its a compound pair already so there could be hidden traps or not. You have to try adding a Q2' lets call it and see.

 

[stajo]

Any verdicts from running this circuit on 24 vdc consumer? Circuit is good, plain, classic and easy with premium modern semis so I cant see why it shouldnt come out good. PCB and the led bar disregarded, just something else as ref.

 

[Salas]

It can go higher than 20V with simply a higher value trimmer so no need to change the Vref.

 

[stajo]

It can go higher than 20V with simply a higher value trimmer so no need to change the Vref.

Thanks. Or top up with some leds I guess if going ptp

 

[Salas]

Certainly. It could be topped up with extra glowbugs in a free hand build.

 

[stajo]

Certainly. It could be topped up with extra glowbugs in a free hand build.

Thanks. Just got multiroom. One digiamp speced 2x50 w (actually sounds decent for kitchen work) came with a 24 vdc 3A laptop like supply. Thats a stretch...

A circuit I tried and liked is this, using npns instead with its benefits. Might be an idea to modernize.

13.8V 20A linear power supply

 

[andrewlebon]

Ladaptor

Hello Salas
greetings i would like to try your Ladaptor for my rasberry pi dac
transformer secondary i want to keep it 0-8 volt AC 4 AMPERES
is it ok just drew a rough pcb
warm regards
Andrew

 

[Salas]

The guide recommends 9VAC Tx for 5VDC. Your drawing will not work well because it misses Rset for the LM334.
It has wrong LM connection too and misses a practical way to easily set a number of active LEDS.

An unofficial board should also have the "clone" indication. Because some people make copies of wrong things they see on the internet and then refer to me for problems.

 

[andrewlebon]

Ladaptor

Hello Salas
greetings and sorry for posting pcb i am only hobbyist i am making
power supply for small rasberry pi dac player i dont see 12 ohms
resistor in the schematic but its in the BOM is it possible to guide me
warm regards
Andrew

 

[Salas]

The LM has V+ R V- pins. Put the LM between rail and LEDS V+ to V-. Put the resistor between R & V-.

 

[vgeorge]

One more l-adapter to power my mini dsp 2X4HD.
The build was super easy.

 

[Salas]

Looks ready for battle.

 

[aljordan]

I had built an L-Adapter a while ago to power a Raspberry Pi and Allo Digi One. I finally ordered a transformer for it. The Pi was being formerly being powered with an iFi power supply. I put it all together yesterday in a way-too-big chassis. I wasn't expecting a change in sound because the iFi didn't sound any different to me than the cheap switcher that I had originally for the Pi. I'm not sure if it is only the power supply, or if putting the Pi in a big metal shield helped too, but it sounds quite a bit better now. The highs lost a little ouchiness they had, and the overall sound nice and warm. I'm quite pleased with the results.

 

[Salas]

Lack of expectation bias is good. Congratulations for your build and result. You could also shorten the DC output cable a little towards the L-A connector maybe.

 

[jimk04]

I use 2 x L-Ad for my Rpi and isolator board. Admittedly overkill for the isolator, it draw a small current.

I strongly advise getting an isolator and powering both separately. Keeps the 'dirty' power from the Pi reaching the dac. And of course using great psus as the Salas L Adapter just makes them shine