OK! Problem solved. It's the adapters (obviously). I found that pins 1
and 3 were also in contact with the outer barrel of the XLR.
Disassembling the adapter separating the 1/4 input section from the
XLR output section made the noise to stop. Thanks a lot for your
advice.
Hector
On Feb 11, 2008 2:27 PM, Philip Tyler <> wrote:
>
>
>
>
>
>
> Hi Hector
>
> Just checking, you have turned the phantom power off
> have you on the FR2 LE? As that could cause problems.
>
> Wiring the earth / screened to both pins 1 and 3
> should not cause problems, unless the input is not
> transformer balanced but electronically balanced. But
> I would have thought that the FR2 LE had transformers
> on its input.
>
> I wire my unbalanced microphones the way I outlined
> and I have not had any problems.
>
> If I am wiring up the balanced output of an
> electronically balanced unit to work into an
> unbalanced device then you only use pins 2 and 1
> leaving pin 3 floating.
>
> Phil
>
>
>
> --- Hector Centeno <> wrote:
>
> > Hello,
> >
> > Thank you for your responses. Yes, I'm aware that
> > the 1/4 inputs in
> > the FR-2LE are line level so the first thing I did
> > was to use a 1/4
> > inch to XLR adapter to plug the AT-822 1/4 outputs
> > (which basically
> > does what Phil suggested: hot to pin 2, ground to
> > pin 1 and 3) but to
> > my surprise I got a loud noise interference
> > (buzzings that seem to
> > come from the electronic circuits) mixed with the
> > audio signal. So
> > following this advice
> > http://www.dplay.com/dv/balance/balance.html#cross I
> > built a
> > 1/4-female to XLR-male cable soldering the hot (red)
> > wire to pin 2 and
> > the ground (white) to pin 3 leaving pin 1
> > disconnected. Now there is
> > no noise! But if I touch the connector on the 1/4
> > end (which is
> > metallic) I get a soft ground hum. Any suggestions?
> >
> > Cheers,
> >
> > Hector
> >
> >
> > On Feb 11, 2008 1:19 PM, oryoki2000
> > <> wrote:
> > >
> > >
> > >
> > >
> > >
> > >
> > > Hector,
> > >
> > > I think you'll have to convert your mic cables to
> > XLR, and not because
> > > of the balanced vs unbalanced signal issue.
> > >
> > > Page 42 of the FR-2LE manual describes the analog
> > inputs
> > >
> > > "These connectors are "combo" type (both 1/4" and
> > XLR) and can connect
> > > an external microphone via the XLR connector or
> > an external line level
> > > source via the 1/4" connector."
> > >
> > > On page 50, the manual says
> > >
> > > "The XLR connection accepts an analog signal
> > between -50 dBu and -10
> > > dBu...the phone plug accepts a -10 dBV analog
> > audio signal."
> > >
> > > -10 dBV is equivalent to -7.78 dBu
> > >
> > > This says to me that the 1/4" inputs won't work
> > well with a microphone
> > > unless the audio source is extremely loud (rock
> > band, plane taking
> > > off, huge crashing waves, etc.)
> > >
> > > To test this idea, I found an inexpensive Radio
> > Shack mic with 1/4"
> > > output in a drawer. I plugged it into my FR-2LE
> > and started
> > > recording. I had to talk in a very loud voice, a
> > shout almost, to
> > > register a signal.
> > >
> > > So the 1/4" input is probably not the right
> > choice if you're trying to
> > > capture a natural ambience. It might be just
> > right to record steam
> > > locomotives, however!
> > >
> > > --oryoki
> > >
> > >
> >
>
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