Creation CK12 capsule and power supply question

[Putchy]

But even before that, you'll want some sort of Faraday cage around the capsule and impedance adapter circuitry. Unless you'll be happy end up with mostly mains & harmonics thereof, instead of useful audio signal.

Yes, I've already built one.

Only if you intend to connect to a high-impedance input. But even so, expect lots of mains hum/buzz and other interference. And before you ask, no, you do NOT want to use the built-in audio in a laptop or a desktop.

What do you advise me to put between the output of the circuit and a recording device in this case?

 

[Khron]

What do you advise me to put between the output of the circuit and a recording device in this case?

If you also wanna record, in addition to viewing waveforms (plenty of ways to do that on a computer), you'll probably want to score a used, if possible reputable brand, 2-channel USB audio interface.