Hello all,
When I have do my A75's front end voltage gain adjustment, found the circuit not very stable. During adjust P1 & P2 VR acknowledge from OCR both input and output signal turn very bad. I think it may due to the circuit self-oscillate. Not sure to change the series resistor value of the Gate of FET would be helpful on it .
Every times I look my PSU display 30mA per channel using. The input signal shaping is good but no output voltage gain. There should not enough power for the circuit, then I try to adjust P1 & P2 VR . Somehow it suddenly surge more current about 70mA per channel then my both input and output signals collapsed.
1) Where and what resistors value can be modified ?
2) Can any other way to restrict the self-oscillation ?
3) Once change the values will the gain also be changed ?
4) Will it be affect by without matching the input differentiate pairs ?
Thanks for your attention.
CK
When I have do my A75's front end voltage gain adjustment, found the circuit not very stable. During adjust P1 & P2 VR acknowledge from OCR both input and output signal turn very bad. I think it may due to the circuit self-oscillate. Not sure to change the series resistor value of the Gate of FET would be helpful on it .
Every times I look my PSU display 30mA per channel using. The input signal shaping is good but no output voltage gain. There should not enough power for the circuit, then I try to adjust P1 & P2 VR . Somehow it suddenly surge more current about 70mA per channel then my both input and output signals collapsed.
1) Where and what resistors value can be modified ?
2) Can any other way to restrict the self-oscillation ?
3) Once change the values will the gain also be changed ?
4) Will it be affect by without matching the input differentiate pairs ?
Thanks for your attention.
CK