On 23/02/2022 20:40, David Satz wrote:
> re: noise measurements on mike preamps -- everyone says that it's a
> So it's way beyond "take those listed numbers with a grain of salt." On the contrary, they're pretty much irrelevant unless you happen to need the gain levels that they were measuring at, AND your microphone's output circuit behaves like a pair of 150-Ohm resistors. It's not just that your mileage MAY vary--it absolutely WILL vary. You would almost certainly make different decisions about preamps if you measured in a way that takes your specific microphones and gain settings into account.
>
In Jake T's case, when using the H2, he is using condenser microphone
capsules integrated with the recorder circuitry directly, so the capsule
impedance is extremely high, and matched to circuitry on the board which
would normally be inside the capsule. IIRC, they are electret condenser
capsules, with all that implies for noise levels. For what it is,
though, the quality is very good, especially for "normal" recording
jobs. The only way to get a noise figure is to put it in an anechoic,
soundproof chamber.
The Zoom supplied H5 microphones are a low voltage powered condenser mic
in a clip on module, and come in various flavours, ranging from a
standard 90 degree crossed XY to a short stereo shotgun. The advantage
of the H5 over the H2 is that the H5 has proper phantom power for any
eternal microphones you want to use, and XLR/ TRS jack combined
connectors, rather than the low voltage unbalanced supply on a 3.5mm
stereo jack of the H2. For silliness, in Jake's application, you could
plug in a long Schoeps shotgun as used on many movie sets for better
gain and noise, but the cost is ridiculous.
Due to the low sound pressures involved, Jake is also running the
preamps flat out, with no pad between the mic and the preamp, which
won't be helping the noise figures.
--
Tciao for Now!
John.