Here's a single sided layout of the Jung regulator alone for anyone who would like to use it for a preamp project. C13 and C14 are .1uf ceramic caps. They get soldered directly between pin 4 and pin 7 of the op amps under the board.
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I would be surprised if those are the real deal.
I've gotten a lot of fake devices(both op-amps and transistors) from them.
I now have the 2 regulators working using artwork on post 480 & schematic on post 487 .... next ... measuring noise & checking stability
Be careful if you use artwork from post 480 2 components are shown inverted ... a LED and a voltge reference.
Also there is one hole for a wire at -15 volt output that should be shifted about 0.3 '' otherwise the hole is under a capacitor.
Be careful if you use artwork from post 480 2 components are shown inverted ... a LED and a voltge reference.
Also there is one hole for a wire at -15 volt output that should be shifted about 0.3 '' otherwise the hole is under a capacitor.
I did some test on the positive supply ..
I did use test load shown below gif attachement
On the scope had results shown in atttached JPG
Positive overshoot reach 0.13 volt.. negative overshoot 0.1 volt
Some part of these overshoot may be the effect of poor wiring around test jig
In steady state after overshoot I had around 15 mV of voltage variation
I did not test negative supply ..
I did test with the same load with a LM7915 used in my bench supply had less oveshoot but more noise that can be seen in the scope screen but impossible to show in photo .. visible as erratic spikes around traces ...
I did use test load shown below gif attachement
On the scope had results shown in atttached JPG
Positive overshoot reach 0.13 volt.. negative overshoot 0.1 volt
Some part of these overshoot may be the effect of poor wiring around test jig
In steady state after overshoot I had around 15 mV of voltage variation
I did not test negative supply ..
I did test with the same load with a LM7915 used in my bench supply had less oveshoot but more noise that can be seen in the scope screen but impossible to show in photo .. visible as erratic spikes around traces ...
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All ceramic caps are not created equal. Those particular CK05 types are not the best because then are probably not NPO(COG) grade materials, usually X7R. If they are like these
CK05 22 pF Multilayer Ceramic Capacitors MLCC - Leaded | Mouser
These are a better choices and alot cheaper than mica. You can always select RF grades if you want to pay more
22 pF C0G (NP0) Multilayer Ceramic Capacitors MLCC - Leaded | Mouser
Film in the feedback path is usually not used normally because of size.
Mica are at least 10x the price and usually not worth the extra $ unless you can prove to the bean counters otherwise
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I did some more construction I did build the 2 diamondbuffer according to the attached JPG.
Both worked ar first time ... bias is around 110 mA and had below 50 mV of offset
Offset can be cured by adding an extra resistor in parallel with R1 or R2 ... so I did ... now offset is below 2 mV
Both worked ar first time ... bias is around 110 mA and had below 50 mV of offset
Offset can be cured by adding an extra resistor in parallel with R1 or R2 ... so I did ... now offset is below 2 mV
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