From Newsgroup: rec.audio.pro
Harvey Sanenbum <
harvey50120@micro.net> wrote:
Does anyone here know the electret specs for the old Zoom H2? I
recently had one go bad and I have removed the four electret elements.
I plan on using the one pair with 90 degree separation as a plug-in for
my other Zoom H2. I know the Zoom can be set to automatically power the >electrets, but I want to have the option of using separate bias voltage
from a 9V battery and would need best load resistor and capacitor specs
for the circuit. Thank you.
I don't now the parameters but most of those electret capsules use the same FET-IC anyway. Give it a try.
If you're going to use them as unbalanced devices with a 9V battery, you
have only two components to worry about. Use a capacitor that is 10uF or larger (a 10uf cap gives you a -3dB point of 20 Hz into a 600 ohm load... double the capacitance and you halve the corner frequency... double the
load impedance and you halve the corner frequency).
As far as the resistor goes, start with 2.2K and try it. Does it overload
too easily at high levels? If so, reduce the value which will increase the current through the capsule. You don't know what the maximum current rating
on the capsule is, so stay conservative.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
--- Synchronet 3.21b-Linux NewsLink 1.2