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How to get rid of peaking in analog filter example?

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Yuu:
Hello, I'm reading Valkenburg's Analog filter design book and I simulated example 3.11. Green is output at R5.



It's a bandstop filter that works alright but as you can see there is peaking at around 2 and 5 MHz. That's undesirable. How do you get rid of that?
I know how to compensate for single gain stages. You basically want the op-amp to be a unity-gain buffer at high frequencies. Well, these things already have high-ish value caps across them!

Valkenburg basically says "oh if the ringing isn't acceptable just replace the op-amp with a faster one." In the example he goes from an LM741 to a HA2542-2. Well, these OPA things I'm simulating with should be decently fast (well, larger bandwidth) AND unity-gain stable so I don't see what the issue is.

Yuu:
Tried a different op-amp and it changed the peak locations. Definitely something going with the filter capacitors making poles with the op-amp internals or something. I'll continue chugging along in the book but it makes me wonder how the heck anyone makes analog filters without making a high frequency oscillator.

Benta:
Is this a question? Your filter behaves exactly as Schaumann/Valkenburg predict.

Yuu:

--- Quote from: Benta on October 02, 2023, 11:29:16 pm ---Is this a question? Your filter behaves exactly as Schaumann/Valkenburg predict.

--- End quote ---


--- Quote from: Yuu on October 01, 2023, 04:32:45 pm ---It's a bandstop filter that works alright but as you can see there is peaking at around 2 and 5 MHz. That's undesirable. How do you get rid of that?

--- End quote ---

Benta:
Well, Valkenburg already answered it.
Seriously, that filter topology is so weird, I've never seen it used in practice (that probably also explains the lack of responses).

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