Parallel shunt RC network of op amp feedback loop

[Miyagi_83]

Hi, everyone.
Probably a basic question here. I've seen a couple of op-amp-based preamp and pedal schematics where the feedback loop leg going to ground is arranged as in the image attached, namely as a parallel combination of two RC networks.
What, if any, advantage does this setup have over the more simple approach, with just one resistor and one capacitor?
Thanks in advance for any input.
M.

[Loudthud]

The one with the smaller cap is providing a treble boost. The one with the larger cap sets the low frequency response.

[Miyagi_83]

Ok, now I get it. Thanks, Loudthud.

[Tassieviking]

The 100pF cap with the Gain pot form a Low Pass filter.
The 15nF with the 27k resistor form  a High Pass filter at 393 Hz
The 470nF with the 120k resistor for a High Pass filter at 2.8Hz
When 2 filters overlap the fall or rise of the filters change.
( as far as I remember)

This is a good link to read up for you:
https://www.electrosmash.com/proco-rat
I like the calculators on this site because I'm lazy:
http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php

[Miyagi_83]

Thank you very much, Tasmanian Viking

[Miyagi_83]

That's some great stuff, guys. I mean, I did know it was a high-pass filter (I'd learnt that from Teemuk's book), but I wasn't aware that putting two in parallel enables you to amplify different frequencies. It opens up a whole lot of design possibilities.

[Tassieviking]

Here is another calculator design tool place thingy, it can be a little bit harder to use:
http://sim.okawa-denshi.jp/en/

You most likely know about the tone stack calculator:
https://www.guitarscience.net/tsc/eseries.htm#RIN=1300&R2=220k&R3=100k&RB=1M&R5=220k&RT=1M&C1=10n&C2=250p&C3=100n&C4=5n&RB_pot=LogA&RT_pot=LogA

If you like to play with tubes here is one I like to use for simple stuff:
https://www.ampbooks.com/mobile/amplifier-calculators/
https://www.vtadiy.com/loadline-calculators/loadline-calculator/

[Miyagi_83]

Here is another calculator design tool place thingy, it can be a little bit harder to use:
http://sim.okawa-denshi.jp/en/

I didn't know about this one. Thanks! I'll check it out when I get home.

[Miyagi_83]

Here is another calculator design tool place thingy, it can be a little bit harder to use:
http://sim.okawa-denshi.jp/en/

Oh, brother, this is awesome! It's got a bunch of useful features. I'm bookmarking it for sure. Thanks again for showing me this