op amp performance: what factors affect quality? Example case ua741 (bottom) versus NE5532 (top) audio signals, why is NE5532 better, what specific factors contribute to its superiority?

Submitted ⁨⁨9⁩ ⁨hours⁩ ago⁩ by ⁨basketugly@lemmy.world⁩ to ⁨electronics@discuss.tchncs.de⁩

https://lemmy.world/pictrs/image/cf0002e6-abe9-4407-8eb1-8acef489b6cd.jpeg

I built two circuits as similarly as possible 1) quad ua741 and dual NE5532. FFT on my Rigol scope showing peaks at 1k and 15k as set/expected (2 channels from Seesil generator are mixed with 1k signal at 80% of 15k signal amplitude) with this I believe I created a tool to do AM with my cheap Seesil generator and can also mix two audio signals.

That said, I have no clue what I am doing. I based my testing procedure off an Elenco radio kit.

So I guess I actually have two questions or areas where I am trying to understand better:

What makes one op-amp better than another? I am talking about the IC itself, I believe. Why is NE5532 better than ua741, I see and hear the difference, now why?
What should I be testing and/or what data should I be collecting to better understand and characterized?

Thank you for your time and consideration. I am 100% self-taught savage from the wilderness and stumbled into your camp, but we are not so different, I promise, just had to walk down different road in life. Thanks again.

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Tolookah@discuss.tchncs.de ⁨9⁩ ⁨hours⁩ ago
The difference you’re seeing is gain bandwidth product. en.m.wikipedia.org/wiki/Gain–bandwidth_product the 741 rolls off at 1MHz and the 5532 rolls off at 10MHz, so it’ll go about a decade higher frequency at about the same performance.

If you want the layout difference, in the 741 datasheet look at section 7.2, and on the ne5532, section 8.2, the schematic is different.

On top of that, the 741 was released in 1968, vs 1979 for the 5532. 10 years is huge.

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- basketugly@lemmy.world ⁨9⁩ ⁨hours⁩ ago
  Thank you, yes I specifically saw a breakdown in my sin wave at ~60 kHz on ua741, and NE5532 got to ~650 kHz before I saw distortion. I thought that was awesome. I will study the layouts as you suggested. Any other advice? Does this also explain the noise floor difference or no?
  
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Sadbutdru@sopuli.xyz ⁨8⁩ ⁨hours⁩ ago
Someone more knowledgeable than me will likely join in soon, but depending on your application one op amp might be better than another because of

higher slew rate (which affects max frequency)

higher unity gain bandwidth (if you need to amplify a wide range on frequencies)

better common mode rejection ratio (for working with small signals and electrically noisy environments)

lower input bias current (for low- power applications)

higher input/ lower output impedance (to not load sensitive instruments/ distort signals)

And probably loads of other things… cost… thermal…
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- basketugly@lemmy.world ⁨8⁩ ⁨hours⁩ ago
  Thank you, perhaps it is the CMRR that I need to explore? Perhaps this explains the noise floor difference? Thank you.
  
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