I want to go step by step.
In my opinion better don't introduce noise so you don't have to deal with it further on the way.
Thats why my focus now is the transformer and the question, if current and voltage variation on the first secondary winding will cause high freq. noise transmitted to the second secundary winding.
To handle AC/DC convertion Im using a Studer 900. Also discused here on the forum.
low noise Pre-Amp / DAC power supply MJE15034 TL072 Regulator based on STUDER 900
That's out of my league, but I can say that super regulators incorporate low pass filters, let's say anything from 10hz gets attenuated to extreme low levels.
Ask Jan didden here on diyaudio, he's the leading guy in silent power supplys.
Regarding your transformer, read the thread on quasi modo bell ringer, it shows a easy jig to provoke trafo ringing and how to silence it
Ask Jan didden here on diyaudio, he's the leading guy in silent power supplys.
Regarding your transformer, read the thread on quasi modo bell ringer, it shows a easy jig to provoke trafo ringing and how to silence it
I have been building small power supplies using the 317 since they first appeared in the UK ,there have a better performance than the fixed regulators .
I could not figure out what the OP was aiming at and now he has said -quote --I will be using a Studer 900 , it would have been more logical to say that in the first place.
Yes I agree with your circuit that's the type of power supply I am used to very easy to build and cheap at the same time , that's what this website is all about ----DIY .
@duncan2 : amplidude was going into detail on the question of ac/dc handling. He did t know about mine.
Still main question is the transformer...how to connect and the consequences.
Having 1 primary and 2 secondary windings...will current variations on 1 secondary winding introduce noise in the second windings.
Variations on 1 secondary winding will influence current flow in primary winding which then is coupled to the 2th secondary winding and causing noise on the signal.
Does this make sence?
Still main question is the transformer...how to connect and the consequences.
Having 1 primary and 2 secondary windings...will current variations on 1 secondary winding introduce noise in the second windings.
Variations on 1 secondary winding will influence current flow in primary winding which then is coupled to the 2th secondary winding and causing noise on the signal.
Does this make sence?
TI has a new version of the LM317 Amplitude.
Noise floor is = 38 uv rms
Does your Studer 900 go lower Mr. HifiTunes ?
LM317 data sheet, product information and support | TI.com
Noise floor is = 38 uv rms
Does your Studer 900 go lower Mr. HifiTunes ?
LM317 data sheet, product information and support | TI.com
What is the best setup then? See picture post #3
2 x 115V in == 2 X 9V out.
I want to connect RPi (max 3A) and DAC 9 (max 200mA) seperately.
My mains = 230V
Any help is welcome
Some get around 2,5uV
\With a modified bord :
quote :
I did some simulation before, it didn't quite match your measured data. The feedback loop of error op did generate noise chart similar to your graph, but the peak value & frequency is very different. and it do move around with load.
load........peak.freq...peak
10mA.........4.4k.......316nV
50mA.........7.5k.......637nV
100mA.......8.8k.......433nV
500mA.......8.5k.......670nV
1A..............6.6k.......337nV
It dose not appear at no load though, and if change 220p compensation cap to 9n.
load........peak.freq...peak
10mA.........750........180nV
100mA......1.43k......3300nV
1A.............1.08k.......190nV
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