Even with my more limited experience, I prefer to run my microphone
through an external pre-amp, to boost it up to line level, and then use
the Line Level Input - even for the microphone - for the reasons you
give for preferring the line level input for other sources.
This parallels and is analogous to how I use microphones on computer
sound cards - the mic inputs have little pre-amps to boost the lower mic
input to line level in the card, and an external preamp is often
quieter, more stable, and less subject to noise and EMI/RFI than the mic
input - for much the same reasons you state for radio input. Similarly,
it is less prone to over modulation/overloading from too strong input
strength.
The bonus on the OMNI VII is the front panel has fewer connectors and
cables coming to it, as the line in input is on a rear panel connector.
Just MY take.
===================== K8JHR =========================
On 7/7/2012 10:55 PM, Bob McGraw - K4TAX wrote:
The typical result can be overdrive of the 1st audio stage which is before
the gain control circuit. Once this stage is over driven no amount of
reducing the audio gain will correct the issue. The 2nd issue is that the
level required to operate the audio stages correctly requires the external
source to be a very low level which is followed by quite high gain
amplification. The result as Gary points out is RF in the audio.
Today's radios that do provide a Line Input are more likely to have a
separate audio path structured at the correct level configuration. They are
much better suited to handle external devices for digital and data
operations.
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