naturerecordists
[Top] [All Lists]

6. Using Line Input/Ext Pre (was Olympus LS-10

Subject: 6. Using Line Input/Ext Pre (was Olympus LS-10
From: "Rob Danielson" danielson_audio
Date: Wed Mar 26, 2008 11:39 pm ((PDT))
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 these 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.


-- 






<Prev in Thread] Current Thread [Next in Thread>
  • 6. Using Line Input/Ext Pre (was Olympus LS-10, Rob Danielson <=
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU