Camcorder XLR Adapter/Preamp/Mixer User’s Manual Page 13
Audio Settings
General Principles and Guidelines
HEADPHONE MONITORING: To be certain that your camcorder and mixer settings are optimized for the signal
being recorded, it is a best practice to monitor the audio using headphones driven by the camcorder. A meter may
indicate if there is sufficient signal. However, a meter gives you no indication of signal-to-noise. The signal level
may be fine, but the audio could still sound poor. This could be because of noise (background, echo, failing mic)
that you would not realize is present. So, it is a best practice to always monitor with headphones. Follow hearing
safety guidelines in the Warnings section of this manual.
DISTRIBUTION OF CAMCORDER/MIXER GAIN: There are numerous combinations of gain settings between the
camcorder and mixer that will result in identical signal levels. However, each combination has unique properties in
terms of noise and dynamic range. The mixer preamp is, in general, a lower noise device than the front end of
most camcorders. Better signal purity will result with the camcorder set to a low gain level, and let the juicedLink
low-noise preamps do the heavy lifting for the gain. This is controlled via various methods for different camcorders.
Higher-end camcorders will have a switch to turn off the ACG, then potentiometers to control the gain. Having the
potentiometers adjusted to approximately 1/3 level is a reasonable starting point. Some camcorders (such as many
of the Sony HDR series) may have a LOW setting. Although this does not turn the AGC off, it sets it at a much
lower level (injecting less noise).
CAMCORDER AGC: Automatic Gain Control (AGC) is circuitry that increases the gain for low signals, then cuts
back the gain for large signals. This is helpful to even out the audio for near/far sources, and prevent overloading
of the recording circuitry. There are definitely environments where AGC is called for, especially where signal levels
can vary greatly and be unpredictable. We chose not to implement a separate limiter in the mixer, since you have
the option to use AGC in your camcorder (and the limiter would add noise and burn current). The downside of the
AGC circuitry is that it always searches for some signal to amplify. During periods of low audio signal levels, the
AGC will start amplifying the ambient noise in the room, or other unwanted noise. If your environment’s signal
levels are generally constrained or more predictable, then the recorded audio quality will improve greatly by turning
the AGC off.
UNPREDICTABLE SIGNAL LEVEL ENVIRONMENTS: In unpredictable signal level environments (say, a kids
birthday party), the wide dynamic range and overload protection of the camcorder’s AGC circuitry.
RECORDING FINE AUDIO DETAIL: It is desirable to get the best noise performance from your equipment while
recording fine audio detail, such as dialogue. In these cases, set your camcorder to manual and throttle back the
gain to roughly 1/3 the level. Then, turn up the trim on the juicedLink’s low-noise preamps. This turns down the
camcorder’s noisy amps, and replaces it with the clean gain from the juicedLink.
Selecting Mixer Preamp Gain
Read the Input Attenuator section for instructions on selecting the appropriate attenuator position.
There are 3 preamp gain settings (HIGH, MED, and LOW). Having a number of gain settings to choose from
allows for an optimal adjustment range of the TRIM control. With microphone inputs during normal use, you will
find that you will be mostly on the HIGH setting. The MED and LOW settings will mostly come into play if you are
using extremely sensitive mics in very high SPL environments.
Adjusting Trim
On unused XLR input channels, turn down the TRIM all of the way. This removes the possibility of unused
channels adding noise to the output signal. Each channel is buffered, so this can be done without adversely
loading or effecting adjacent channel signal-to-noise ratio (unlike many passive adapters).
Read the previous sections DISTRIBUTION OF CAMCORDER/MIXER GAIN and CAMCORDER AGC for an
understanding of the principles and guidelines for the camcorder and mixer gain settings.
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