I sorta knew this at a surface level, now I know it better. Thanks.

You can also use a microfarad cap on the offset null as well and yes you can use a trim pot and once you get it set you can put a resistor or two resistors in place of it to replace the trim pot. Some trim pots create noise. And using a microfarad cap or even a polyester film cap can help alleviate that noise.🤗 I'm self taught so I learn from experience LOL. A lot of times it is to ensure that the offset null is removed from the output so you set the trim pot at zero. But of course it all depends on how you plan to use it with the long tail pair. And also of course you can use a trim pot and a resistor together. And of course the trim pot will adjust itself after time so you will have to go back in side the amplifier and adjust the trim pot again.

At 8:00, input bias CURRENT generates offset voltage if the I_b R_i are different. Care must be exercised, however, because the bias currents are also not typically equal... see input offset current, I_OS. The nA of the OP07 are seldom important. But input voltage is due to different V_be for the differential pair. This ratio drifts with time and temperature limiting the efficacy of the NULL option... see input offset drift. You can always add DC voltage to one of the inputs even if the chip has no nulling terminals. Horowitz and Hill "Art of Electronics" has a section showing how input transistor IC layout is optimized in precision devices. We do what we can to minimize how much device imperfections affect our designs.

Excellent explanation, thank you very much.

Great explanation, thanks.

I found “INTRODUCTION TO ELECTRONIC AMPLIFIERS” by Rodney B. Fabre. -1971 I love this book already. God Bless.

Thanks for the bonus IC de-lidding.

Basic question: How does a 0 volt input have any effect since the op amp's input transistors would need the base to be at roughly at least .6v (BE diode drop) to start conducting.

Nice!

Absolutely awesome video! That makes things so much easier to understand. I was looking at the NE5534 to play with since they're available and cheap and seeing your example makes their application note make so much more sense. Curious, what is the model of that meter on your bench? I'm in the market for a bench meter.

Merci!

Hello. Thanks for this video, I have an issue with and active speakers tweeter output having -23v Dc at the terminal, could this be from the opamp being unbalanced after a mosfet change in that circuit?

What's going on in the bottom right corner of the chip? Is that some kind of damage or just some dust or something obscuring the view?

What about Vdd and temp variations once the pot is nulled

The spec sheet for the NE5532 shows diodes across the two inputs, the spec sheet states the inputs cannot exceed -vcc or +vcc , would'nt this much voltage burn out the diodes across the inputs? I am confused.

I can totally understand that and I agree with you great video. 🤗💯💖 Yes you have to use extra parts so you might want to go ahead and by the genuine one 😂 either way you're going to spend the money of approximately $6 or more

What value resistors did you use

Oh pee zero seven