naturerecordists
[Top] [All Lists]

Re: converting unbalanced signal to balanced and FR-2LE

Subject: Re: converting unbalanced signal to balanced and FR-2LE
From: "Philip Tyler" macmang4125
Date: Mon Feb 11, 2008 11:27 am ((PST))
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
> >
> >  
> 



      __________________________________________________________
Sent from Yahoo! Mail - a smarter inbox http://uk.mail.yahoo.com






<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