Quoting david &lt;gnome(a)hawaii.rr.com&gt;om>: They do require a sort of preamp, but every soundcard which provides the 5V supply voltage for the electret capsule will have such a preamp. These 5V mic supplies are usually in every "normal" soundcard. I'm not talking about the ones you buy from the store but the ones which are included in your computer by default. HAMs will like a bit of soldering, so check this out: http://www.epanorama.net/circuits/microphone_powering.html It includes information on how to connect the capsules and information on the voltage provided by mic inputs on soundcards. Electret capsules can cost < $1 so it should be cheap enough for your needs. Sampo