low noise Pre-Amp / DAC power supply MJE15034 TL072 Regulator based on STUDER 900

studer 900

Yes I thought of that. Do you by any chance have the resistor value for max current, 4A?
An other thought was, is there a better low noise opamp?

For the nuc endpoint it takes less than 1,5A. And the nuc server I do not know jet but 3A should be good.

I have used these supplies and been guided by the Sigma 11 thread in regard to voltage drop. Around 7V seems to work . I did enlarge the heatsinks.

I haven't used more than 1A through the supplies and quoted max has been 2A.

Martin.
 
Hello,


I'm using one of this in my raspberry+katana, 5v 3amp both. It works fine. I bought this:
Kit de placa de alimentacion de amplificador STUDER900 con disipacion de calor en Amplificador de Electronica en AliExpress.com | Alibaba Group


This kit can supply 5v 3A without changes. First tried 12v ac and it gets too hot, can´t touch heatsink. Then I changed to 6v ac and works perfect.





I had some problem setting voltage, maybe this helps others:


VOLTAGE RANGE: there is 3 solder bridges marked as H M L (High-Medium-Low). Left open the voltage you need, and close other 2 with a solder blob. Then turn pot, very easy to adjust to 0.01v.



Victor
 
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I am really confused about this board.
Same pictures...same board on audiophonics,ebay,aliexpress...but different info abut max current...from 1A to 2A.
I can see some people say it can do 3A.
:confused:
 

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@nikolacigo

You can't trust the specs. because they don't state the voltage at which the stated current is available. The ebay merchants are mostly re-sellers who don't know much about the board at all.
With an appropriate AC input you should be able to get 1.5A at 5V. If you want a continuous 1.5A you would probably need bigger heatsinks.
I'm successfully using a 5V boxed version to supply my RPi 3B+ (slightly underclocked and under-voltage). I had to fit a lower current-limiting resistor to get enough current. The MJE15034 transistor is heatsinked to the case, which gets only slightly warm.
 
Victor, If you use this board as a main PSU for the Katana kit supplying 12AC to it it is no suprise that the small heatsing cannot cope with the dissipation of a large amount of heat created... 12VAC x 1.41 = 16.92VCC after rectification and smoothing... meaning a drop of 12VCC to regulatory 5VCC. If you multiply 12VCC with the value of the current required for the task you'd get a self-explaining figure measured in 'watts'. A bigger heatsink or a quiet fan would help a lot in such cases. Are you sure that you've supplied 6VAC during the 'successful' trial...? It's a bit too low to work properly, I believe, maybe it was 9VAC...
 
Hi vitorio!
What model of Rpi do you have!?

Raspberry Pi 2 model B

I'm surprised that it can work with as little as 6V ac. The Studer circuit (see pdf linked to in this thread) shows 10V across the TL072. Perhaps the actual output of your transformer is more than 6V?

Hi Jonners

You are right. Transformer label says 6+6 volts, but I measured it and actually is 7.0V ac under load. Output 5.0V dc and 6mV ac (standard multimeter). Heatsink is just warm, I can keep my finger on it.
Do you think 7.0V ac is too low for regulator? Can I expect improvement going to 12V ac again? If I do, I should change heatsink.

Thanks
Victor

Victor, If you use this board as a main PSU for the Katana kit supplying 12AC to it it is no suprise that the small heatsing cannot cope with the dissipation of a large amount of heat created... 12VAC x 1.41 = 16.92VCC after rectification and smoothing... meaning a drop of 12VCC to regulatory 5VCC. If you multiply 12VCC with the value of the current required for the task you'd get a self-explaining figure measured in 'watts'. A bigger heatsink or a quiet fan would help a lot in such cases. Are you sure that you've supplied 6VAC during the 'successful' trial...? It's a bit too low to work properly, I believe, maybe it was 9VAC...

You explain it perfecty. I didn't my homework and had to fix it later :)
 
I recently purchased this Sturder KIT, I soldiered it and have few issues.

1. Toroidal transformer have 6V AC output (after connecting Sturder psu have 7.3V DC at the output)

2. Led are not glowing

3. It cannot regulate voltage (tinny screw)

4. By soldiering L/M/H contracts nothing change, it gives voltage at the output also when not soldiered