4700uF capacitor driven by op-amp

LTSpice example LoopGain2.asc is very convenient for checking opamp stability with capacitive loads. Using the same capacitor as Elvee did, resulted in critical margin of only 5°. However, using only 0.1Ω for R4 resistor, results with 63° margin.

LoopgainLT1050.png
 
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My guess is that this is similar Vref RC filter for AK4499EX as in AK4499EQ evaluation board. Some AKM DAC datasheets suggest adding a RC filter for Vref in especially noisy conditions. Some here even claim that it improves sound.
 

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