with Sony's low priced MD recorders explained
-R70/71, -R90/91, -R700, -N707)
Sony omitted the microphone
pre-amp's "low sensitivity" (-20 dB) setting on these recorders, so they
are often prone to mic pre-amp overload distortion (sometimes referred
to as "brickwalling") when recording even moderately loud sounds.
To resolve this issue,
there are several solutions:
- Use less sensitive microphones.
This works, but unfortunately, many low sensitivity microphones are
also lower in overall sound quality. Even when they are high quality,
the built in Sony mic preamp will add a noticeable amount of noise to
the recording. This is generally not a good solution for high fidelity
- Use an attenuator between the mics
and the mic input. This also works in some cases, but will lower
the bias voltage getting to the microphones (for those that require
it), which also lowers the maximum SPL the mics themselves can then
handle (sort of a catch 22). So, you solve one problem while potentially
creating another. However, this is a workable solution in situations
where the mic input is just beginning to overload....the attenuator
knocks the signal down just enough to eliminate the overload, but because
the sound isn't too loud, there is still enough bias power to run the
mics properly. Here
is an attenuator cable that will work in this situation. Usually,
with this cable, setting the level control at it's highest setting lowers
the signal just enough to eliminate the overload. Keep in mind that
even when this works, you are still adding some noise from the Sony
- Use a microphone power module with
level control. This solution will allow you to make all types of
recordings without distortion. Loud recording would be made using mics
plugged into a power module and the power module plugged into the 'line'
input of the recorder, thus bypassing the mic input of the recorder
completely. Medium loudness recordings would be made by plugging the
power module into the mic input, but with the level control of the power
module turned down sufficiently so that the mic input does not overload.
Quiet recordings would be made with the mics plugged directly into the
mic input. This is a pretty good solution, with the only drawback being
that you would still need to use the mic input for medium loud recordings,
thereby still adding some noise from the mic preamp of the recorder.
Here is the section of microphone
- Use a separate high quality microphone
preamplifier. This solution offers the highest quality recording,
albeit at the highest cost. Using a separate preamp will allow you to
make recordings of all kinds, with low noise and no distortion. Here
is an example
of this type of preamp.