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

[Finnegann]

Sidenote: Just based on listening, this board like many similar power supplies may not like low esr caps. Especially the 470uf at the output. Nichicon FG sounds good there.

 

[v4lve lover]

where is the red led near the right opamp?

 

[kecstama]

where is the red led near the right opamp?

Oh, I forgot those.
Seems to be good now, after adjusting the potentiometer to 1K/9K.

The output is still "wavy" or is this how it supposed to look?

Thanky you btw!

 

[Anatolii_A]

Has anyone tried two-half-cycle rectifier with transformer midpoint with this power supply ?

 

[v4lve lover]

Oh, I forgot those.
Seems to be good now, after adjusting the potentiometer to 1K/9K.

The output is still "wavy" or is this how it supposed to look?

Thanky you btw!
View attachment 1308360

Its supposed to be a straight line. perhaps this is oscillation?

 

[kecstama]

Its supposed to be a straight line. perhaps this is oscillation?

I have no idea, but I couldn't fix it, so I remade the whole thing from the schematic in #343.
The output is still bad tho.

What I've noticed is that modifying the potmeter values does nothing to the output, but I cannot see any wiring mistakes.
+If I lower the value of the 10KuF filter cap, the sawtooth becomes steeper, but increasing doesn't fix the issue.

 

[v4lve lover]

what is the input voltage? your regulator may be dropping out.

 

[kecstama]

what is the input voltage? your regulator may be dropping out.

Tried 28V, 24V, 9V and 8V, but it doesn't change the output.

It may be just a simulation error.

 

[v4lve lover]

that is likely a simulation error indeed.