I'm sure this is not pop corn noise - maybe just bad layout.😉
Testing the opamp on breadboard without close connected decoupling caps is just pure idiotic nonsense...
Decoupling is very important, also the 47R resistor at output of opamp (many circuits ignore the data sheet recommendations). If layout/decoupling is bad, you can't easily change to another opamp type without troubles. If e.g. a design is made for low impedance one cannot replace a LM4562 (easy drives 600R output) using an opamp which doesn't like output impedance below 2k.
Of course there exist badges with defective opamps. Glad that mine are all OK.
My MC preamp uses NE5534/LM4562 and the preamp tons of LM4562 and produces just random noise (with ultra low level!) if using full gain.
If the LM4562 and other high end opamp's would be so bad, why are the prices so high?
Have fun, Toni
P.S.: have also many LME49990 on Stock ... great parts
Testing the opamp on breadboard without close connected decoupling caps is just pure idiotic nonsense...
Decoupling is very important, also the 47R resistor at output of opamp (many circuits ignore the data sheet recommendations). If layout/decoupling is bad, you can't easily change to another opamp type without troubles. If e.g. a design is made for low impedance one cannot replace a LM4562 (easy drives 600R output) using an opamp which doesn't like output impedance below 2k.
Of course there exist badges with defective opamps. Glad that mine are all OK.
My MC preamp uses NE5534/LM4562 and the preamp tons of LM4562 and produces just random noise (with ultra low level!) if using full gain.
If the LM4562 and other high end opamp's would be so bad, why are the prices so high?
Have fun, Toni
P.S.: have also many LME49990 on Stock ... great parts
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The LM4562 is renouned for having a significant fraction of devices with excess noise (which TI really don't like being mentioned!) Its also one of the worst for EMI pickup, alas. It also has more current noise than the good old NE553x devices. Basically its not a good choice for any kind of preamp.
But you are right about decoupling, you can't get away with sloppy decoupling on an LM4562, unlike some chips it needs decoupling from each rail to ground, not just between the rails. Distortion jumps 60dB or so if you get that wrong!
[ I got that wrong, once... ]
But you are right about decoupling, you can't get away with sloppy decoupling on an LM4562, unlike some chips it needs decoupling from each rail to ground, not just between the rails. Distortion jumps 60dB or so if you get that wrong!
[ I got that wrong, once... ]
SA2022 uses mostly all LM4562 in high current low gain circuits where popcorn noise is hard to measure and not even hear able. NE5534 is used in MM (high input impedance situation with high gain) and MC circuits (high gain).
Never had any LM4562 showing the popcorn noise problem. Maybe because I have bought most of my LM4562 in the year 2012 where National Semi produced them in 2012 or before 2012.
Never had any LM4562 showing the popcorn noise problem. Maybe because I have bought most of my LM4562 in the year 2012 where National Semi produced them in 2012 or before 2012.
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Hello, good morning.
I'm interested in this project.
Do you have the complete board set for sale?
Please tell me the price and how to purchase.
I've also asked you for the price of the SA2023 project in its thread.
Best regards.
I'm interested in this project.
Do you have the complete board set for sale?
Please tell me the price and how to purchase.
I've also asked you for the price of the SA2023 project in its thread.
Best regards.