At 6:49 PM +0000 3/26/08, Phil Tyler wrote:
>Excellent info Raimund!
>
>Is there any merit in giving results for the line input? The reason
>I ask is that there seem to
>be a number of people using separate mic pre-amps and the info might
>be useful?
>
>Phil
>
Hi Phil--
Its always smart to ask and confirm, but the engineering should be
fairly straight-forward for Olympus and the other manufacturers to
provide very low-noise performance using the -10dB "line" input set
at unity gain. To match FR2-LE or Hi-MD performance, one would need
an external pre with comparable noise performance and the cost of
these is as much or more than the recorders. If you have SD MP-2 or
Mix Pre that you aren't using, hook it up to the line input on an H2
and you _should_ have a very high quality combo. As a reference, the
lower cost portable pres folks are suggesting have noise performance
around that of the LS-10 so there's not much point in that route if
lower noise is sought. A good percentage of the pres have only 40dB
gain which many would find too low for nature recording.
Based on Raimund's noise spec for the LS-10, one would need mics with
around 15dB(A) self- noise or lower to hear the noise from the
LS-10's mic pre at maximum gain. That number drops to around 12dB(A)
for Hi-MD and the FR2-LE's pre noise is likely to be inaudible with
quietest mics we typically use.
It adds bulk, but one can use a Rolls PB224 portable phantom supply
and connect lower-noise mics like the AT-3032's to the 3.5mm mic
input. The recorder's noise would be audible with these mics but the
noise performance should be much improved compared to that of mics
with >16dB(A) self-noise. Rob D.
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