Raimund,
I'm trying to understand this problem. =C2=A0Are you saying that the microp=
hone is drawing power from the phantom supply in an unbalanced way, and pos=
sibly causing different amounts of noise from the phantom supply to show up=
on the two legs of the (supposedly) balanced circuit? =C2=A0Or is it that =
the output impedance of the microphone is unbalanced in the two legs and th=
us causes the amount of noise in the two circuits to be unequal at the two =
inputs to the microphone preamp?
It had occurred to me some years ago that it would be very useful to see te=
sts of the output impedance of microphones, both the common mode part and t=
he differential part. =C2=A0It would show how well the system (microphone, =
cable, and preamp) do at rejecting noise from external sources.
Eric
From: " [naturerecordists]" <naturerecordists@=
yahoogroups.com>
To:
Sent: Tuesday, May 13, 2014 1:55 AM
Subject: [Nature Recordists] Re: Fostex FR-2LE ?
=C2=A0
Hi H=C3=A5kan,
I agree with you that there is no reason to worry about that minor phantom =
power noise issue on the TASCAM DR-680.
The person who published that "problem" also contacted me privately and rep=
orted the details. He used a cheap Behringer B-5 microphone that obviously =
lacks a balanced output stage.
Some time ago we discussed here a similiar effect on the Roland R-44 (and R=
-26) in combination with an unblanced DPA phantom power adaptor. So, there =
are similiar effetcs in other recorders too.
Fortunately, all these phantom power related noise problems will go away as=
soon as one uses a properly balanced microphone.
Regarding your note on the external preamps: I don't hink that you are miss=
ing anything here. There seems to be some kind of a placebo effect that mak=
e some folks believe that a preamp would improve the recordings even if the=
re is no objective poof for that...
Regards,
Raimund
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