Bode plot for opamp circuit is different depending if LTspice used, or Excel...why?

[Flyback]

Hello,
Please can you advise on why the Bode plot for an opamp circuit is different depending on whether I use LTspice to get it , or when I calculate it in Excel?
(If I do the Bode plots for a simple, passive RC circuit, then they are the same whether I use Excel or LTspice)
The below shows the opamp schematic in question, and the bode plots, plus LTspice simulation.
For example, at 50.31KHz…
Excel gives a gain of -6.74dB & phase of 163 degrees
LTspice gives a gain of –9.202dB & phase of 155 degrees
Also, as you can see, at low frequencies of around 1Hz, the gain and phase are massively different between Excel and LTspice.
The LTspice bode plot is the red one and the phase is a broken line.
Do you know the reason for the differences?

 

[MikeMl]

I would question your ability to model an opamp in Excel

 

[Flyback]

But the opamp has a massive DC gain......and in any case, when you get above 10Hz or so, the opamp factors just disappear.....and it is just Zfb/Zin.

opamps with feedback have characteristics which don't depend on the opamp parameters..i thought that was the whole poinf of opamps with feedback...the output depends on zfb and zin and not the opamp parameters?

 

[MikeMl]

By the time you get to your stated frequency of 50kHz, the specific opamp model has a large effect on what happens, as do parasitic capacitances. Sounds like you need to compare three cases: A Spice circuit using an ideal voltage-controlled voltage source, a spice circuit containing a specific opamp model, and an Excel simulation using an ideal voltage-controlled voltage source.