naturerecordists
[Top] [All Lists]

Re: Sharp minidisc MD DR7

Subject: Re: Sharp minidisc MD DR7
From: "Adam Liberman" <>
Date: Tue, 25 Nov 2003 06:27:51 -0000
I'll add my 2 cents:

1) The plug-in-power can cause a loud crackling noise when the mic 
plug wiggles slightly or rotates. It may depend also on what mic you 
are using, and is probably more of a problem with dynamic mics as a 
variation of the resistance at the jack will cause the "plug-in-
power" voltage across the mic element to vary. Therefore, you may 
find it necessary to add a blocking capacitor. I use a Panasonic FC 
27uF/25v capacitor. It fits inside the XLR connector and only causes 
a roll-off of 0.3dB at 20Hz measured with this model.

2) Several news reporters have complained to me that this model has 
a noisy mic preamp. You will get better results with a high-output 
condensor mic instead of a dynamic, but as nature sounds are often 
of low intensity and need high gain, you should make sure that you 
get acceptable noise results with the combination of recorder, 
microphone, and subject matter. Eventually, I hope to do comparitive 
measurements to quantify the problem with different recorders.

3) You may get better noise performance using a matching transformer 
(200 ohm input to "medium impedance" output), but this will depend 
on what input impedance the mic preamp is optimized for (which I 
haven't myself tested). Most consumer mics that would accept plug-in-
power are likely to have a 600 ohm output impedance, which may be 
why (combined with the crackling problem) they recommend these mics, 
even though they are unsuitable for professional use.

- Adam Liberman
Liberman Sound

Thanks,
Adam

--- In  Vicki Powys <> 
wrote:
> 
> Can anyone confirm if the Sharp minidisc MD DR7 (which may also be 
listed as
> DR480) will only accept microphones that use plug-in power?  The 
manual
> suggests using only "mics that can be powered from the mic 
socket".  What
> would happen if you used a battery-powered mic such as a 
Sennheiser K6
> series mic?
> 
> Vicki Powys
> Australia



________________________________________________________________________
________________________________________________________________________

<Prev in Thread] Current Thread [Next in Thread>
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