Hi,
I recently bought a Fostex FR-2LE and I've been making some test
recordings with it. I've noticed a steady tone that shows up only
when phantom power is turned on. When sampling at 96/24, the tone is
on both channels at about 30,700 Hz; with trim and gain up full,
using AT 3032s, it is about -66 dB (L channel) and -72dB (R
channel). If the internal mics are used, with phantom on, the tone
is there, but at a lower level. When sampling at 44/16, the tone is
somewhere around 16 kHz, about the same levels. If phantom is turned
off, and internal mics used, there is no such noise at any sample rate.
I assume this is electrical noise from the switching circuit used to
generate the P48. Has anyone else observed it? Is this typical of
the Fostex, or do I have a bad unit? And why would it change
frequency depending on the sample rate?
It's a small amount of noise, but if you shift the 96/24 file down
three octaves, it is definitely audible.
Carter Scholz
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