I am truly confused with this amp right now. Everything appears to be functional yet I have an lm317 where the lm337 is supposed to be. Isn't that the same as having a 7912 where a 7812 should be? How is this amp still working? According to the schematic u4 should be an lm337.
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you are correct, but maybe its a mistake in the schematics?
To check it out, just measure the voltages at the opamps: TL 072 has negative voltage on pin 4 and positive voltage on pin 8.
If thats the case - dont worry 🙂
To check it out, just measure the voltages at the opamps: TL 072 has negative voltage on pin 4 and positive voltage on pin 8.
If thats the case - dont worry 🙂
But here's the deal. I have an identical amp that's not working that has a lm337 there. Should I try and swap a lm317 in its place?
i would check opamp voltages on both amps to be sure because i dont know if they published another schematic revision or changed the layout...
if negative voltage is on pin 4 of the opamps and postive on pin 8 you dont have to change the regulators, its a quick test 🙂
if negative voltage is on pin 4 of the opamps and postive on pin 8 you dont have to change the regulators, its a quick test 🙂
-26 is not good, it should be around +- 15-19V
maybe regulator or adjustment resistors damaged/ out of tolerance?
Negative is Pin 4 ?
But seems ok, the LM 317 is the positive regulator and your positive voltage looks good as long as it is present on pin 8 of the opamps.
maybe regulator or adjustment resistors damaged/ out of tolerance?
Negative is Pin 4 ?
But seems ok, the LM 317 is the positive regulator and your positive voltage looks good as long as it is present on pin 8 of the opamps.
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Do you have an LM337 to replace it with?
If so, confirm that the resistors are within tolerance while the regulator is out of the circuit.
If so, confirm that the resistors are within tolerance while the regulator is out of the circuit.
So i was able to round up a lm337. The voltages on the op amps are +/- 17vdc now. What's weird is aside from the voltage change, the amp runs the exact same. Even the temperature of everything is the exact same.