Need Advice for a Weird Project

Great, for consistency I've attached the updated schematic and KiCAD archive (the Gerbers don't change). I gather you have got used to soldering SOIC-8 packages?

I have gotten better! I changed out my solder tip to a curved one and it was a game changer for me. I am curious, would it be possible to have the high-pass filter elements on a switch too (like the gain adjustment)? That would allow me to use the preamp on other projects as well (for general bioacoustic monitoring). Your thoughts?
 
You know better than I do whether 80 Hz is too high, as you know more about bioacoustic monitoring.

Start-up time is the time between the moment you apply the 5 V supply and the time the amplifier starts working as it is supposed to. It is presently about 1 second. How long could it be without becoming inconvenient?
 
I haven't tried to fit it on the PCB design yet, but the version with switchable cut-off frequency would be something like this. The lower cut-off setting is about 130 Hz. The modified amplifier needs about 5 seconds to settle instead of about 1 second.
 

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Awesome! I wasn't sure it would be possible/feasible to put the HPF on a switch. This will greatly improve the usefulness of the preamp to beyond just night flight calls of birds. I am already formulating a frog call project that would be able to utilize the preamp.

On another note, PCBWay screwed up my last order of 20 boards so I have a pretty good credit with them now. I will hold off on ordering until we can get a layout for the new design. The thought has also crossed my mind that you may want a copy of your designed PCB. If you would like I can certainly send you a copy or two (PM me your address). Thanks Marcel!
 
What about calling it the "ecotone" or "ecotones" preamp? One more thing that came up I wanted to ask about. The current PCB footprint fits near perfectly in the microphone housing as previously designed. There is room for expansion horizontally. There is about 1.2 cm of room in that direction. I have attached a photo to illustrate. Would it be possible to add the new switches and stay within those dimensions? If not, no big deal. Thanks!
 

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See the attachments. Switches SW2...SW4 together are one triple DIP switch; each of them has a single switch footprint in the KiCAD database, but as I placed those at a 0.1 inch pitch on the board, you can actually not use three single switches but only one triple switch. Everything (only just) fits in the area you asked for.
 

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Hey! Yes indeed. I meant to make a post last week but got too busy. I built it a couple weeks ago and been testing since then. I attached a couple photos of the setup. Switches 2,3, and 4 work well. One thing I noticed and wanted to ask about is if there is levels of filtering depending on which switch is used. It seemed like with just switch 2 pushed it was filtering some. Would love to know your thoughts.
 

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