User Guide

Dynamic Processing
Unity Gain
When working with signals that are constantly at a high level, the channel gain can accommodate these signals
with ease. When working with varying signals (such as the vocalist discussed earlier) it may be desirable to reduce
the dynamic range of the signal so that the loud parts aren’t so loud (and don’t overload your channel input) and
the quiet bits aren’t too quiet (so the signal to noise ratio would be increased).
Limiters and Compressors have a similar function which is to reduce the dynamic range of a signal. The means by
which they do this won’t be discussed here but, these devices have the ability to reduce the level of loud signals
automatically and also raise the gain to ‘make up’ the level as desired. The channel gain can now be set with
adequate headroom to accommodate both loud and quiet signals and the compressor can reduce the dynamic
range and ‘make up’ any reduction in level. By inserting such a device into the channel’s insert point you have the
ability to remove the guesswork from setting your system gain.
However (and this is a big however), there are still sources of potential problems. The Verona is able to operate at
levels up to +21dBu on both the insert send and return. If the maximum input level of the compressor was less
than +21dBu then it is possible to overload the input of the compressor. The only way to resolve this situation
would be to drop the channel input gain so that the input level of the compressor was not being overloaded. Bear
in mind however, the level returned from the compressor would also be lower than +21dBu and excessive use of
the compressor ‘make up’ gain would overload the output of the compressor!
Unity gain is a gain of 1 (i.e. no gain or attenuation is applied to a signal).
If a signal entered a mono line level input of the Verona at 0dBu and the gain was set to +15dB (an internal 15dB
attenuation sets the net gain to 0dB), then the signal was routed to each output at 0dB, the channel fader was set
to 0dB and each output fader was set to 0dB, the output should be 0dBu (or unity). Some console manufacturers
mark the 0dB level of their faders and pots ‘U’.
Simple. But that’s just one signal. If we have two 0dBu signals entering the Verona (assuming they are coherent -
i.e. the same level and phase) to be summed in the busses, the output would no longer be 0dBu.
Simply,
0dBu = 0.775 volts
0.775 volts + 0.775 volts = 1.55 volts
1.55 volts is 0.775 volts +6dB (or a gain of 2)
To retain an output of 0dBu (our previous unity level) each input must be reduced.
0.775 volts / 2 = 0.3875 volts
0.3875 volts is 0.775 volts -6dB (or a gain of 1/2)
So each fader must be reduced to -6dB to retain the unity gain level of 0dBu on the console output. When using
four inputs at 0dBu, the faders must be reduced to -12dB. Real life signals are not continuous, but the principal is
the same. If you have a sinusoidal input that is nominally 0dBu on all 48 inputs with the channel faders at 0dB, the
output is likely to be well above the 21dBu maximum output of the console and leave no headroom spare. With
real world signals, 48channels summed together will give around 6 to 9dB gain because it is unlikely that all 48
channels will receive the same signal at the same time. Instead signals will occur at different times, and there will
be cancellation due to phase and frequency differences.
Operators Manual - Page 29
Setting Up The VeronaSetting Up The Verona