u/strictlyforsupport

https://preview.redd.it/s8bgm9n73gbh1.png?width=737&format=png&auto=webp&s=15bb40caa1d8f5dbe8477dd1965cbc1dfa246836

Hello, I'm building a microphone preamp based on this schematic. My question is about protecting the output circuit. Say I accidentally plug it into the audio output of, say, a computer audio interface or electronic instrument instead of the intended audio input, this is likely to damage C4 due to reverse polarity, is that correct?

If so, I'm trying to think of ways to build protection into the circuit to prevent that from happening. Normally, I'd think to make an op amp buffer, but since this is a single supply this would rectify the AC signal.

Would a NP capacitor do the trick? That would be convenient seeing that those are so often recommended for audio circuits.

Thanks in advance for any advice!

I purchased a few of these cheap MAX4466 electret microphone amplifier modules (here's an article on them) and decided to switch out the stock EC mic with a nicer low noise EC mic, the AOM-5024L-HD-R.

It works, and indeed has significantly less noise than the stock mic, but there is a pronounced loss of high frequencies above 5khz when doing some rudimentary A/B testing just recording an acoustic guitar into a module with the stock mic, and a model with the AOM-5024.

The AOM-5024 is supposed to be professional grade, and the frequency response in the datasheet linked above shows consistent readings between 5khz to ~15khz, so I don't think it's the mic itself.

I have a very rudimentary understanding of electronics, but not enough to the point where I would know where to look in the schematic of the module to see where there is some low pass filtering that I can modify. If there isn't any, perhaps then I should consider adding some sort of active high shelf to the output? It's a learning opportunity!

Below is the schematic for the module. I'm happy to provide more information if needed. Any advice is helpful, thanks!

https://preview.redd.it/qptgor4eb3ah1.jpg?width=750&format=pjpg&auto=webp&s=7097be7185f807ba1a463bf05f60e20b17e21180