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Old 30th December 2015, 11:03 AM   #1
vivanco is offline vivanco  Italy
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Default questions about aleph 2

first question:
if you use silver mica capacitors in the position 1nF, is correct?
second question :
what value of volts should be measured at the ends of the resistors with a value of 1 ohm ?
the supply voltage that I'm using is 45-0-45 VDC

thanks
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Old 30th December 2015, 11:11 AM   #2
Zen Mod is offline Zen Mod  Serbia
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re-post schematic you are using , post plenty of pictures

silver mica is good , but ceramic is good also .......... so - unless you already have silver mica , don't waste money on it
however ..... these few questions I already answered

(OK , once more - 500mV across 1R source resistor)

Click the image to open in full size.



10pF cap , in feedback net , that one is preferable to be silver mica
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Old 30th December 2015, 11:18 AM   #3
vivanco is offline vivanco  Italy
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I'm sorry if I made errors of repetition, unfortunately I do not speak English and therefore I use a web translator;
in your opinion what is the cause of 0.370 mV
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Old 30th December 2015, 11:27 AM   #4
Zen Mod is offline Zen Mod  Serbia
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see edited schematic

changes marked with red dots - change two resistor values and add two additional multiturn trimpots

during setup procedure - both inputs shorted to gnd , no load at output

you have 370mV instead of 500mV across source resistor ( so decreased Iq) - simply slightly different batch of mosfets than Papa was using

that's normal thing

anyway - matched output mosfets are absolute must !!
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Last edited by Zen Mod; 30th December 2015 at 11:29 AM.
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Old 30th December 2015, 11:47 AM   #5
vivanco is offline vivanco  Italy
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well thanks for meaningful explanation,, hello and Happy New Year to you and to the entire board !!!
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