microphone cap test

Did a simple test

disconnected the capsule from a microphone build.

Installed a 100pf polystyrene cap in its place one side to the capsule charge voltage and the other to the input

I could record my voice talking at the cap could be a cool recording effect a polystyene cap inside a microphone grill as the transducer.

Ricardo has posted about microphonic caps

I finished building a microphone design of mine yesterday and tested this. Have others that tested input caps grounded the other side of the cap? if so test with the capsule charge voltage.

Hi Gus

I have also come across this with rolled polystyrene caps which were put in place as a proxy for the real capsule whilst testing. But I hadn't thought of using it as a sound effect. 

We shouldn't be too surprised - capsules are capacitors anyway.

Cheers!
Stewart

Just remember if you use audiophool polystyrenes to connect your capsule to the FET, it is adding this to the signal too.

NPO/CGO ceramics don't usually do this ... or do it at a much lower level.

Just one more reason to rewire things to eliminate the JFET gate coupling cap...

ricardo said:

Just remember if you use audiophool polystyrenes to connect your capsule to the FET, it is adding this to the signal too.

NPO/CGO ceramics don't usually do this ... or do it at a much lower level.

Click to expand...

Khron said:

Just one more reason to rewire things to eliminate the JFET gate coupling cap...

Click to expand...

Exactly!!!!