Alice 561 Noise Gate with limiter
561 500 series NOISE GATE with limiter
A Noise Gate is designed to clean up and isolate individual microphone signals by allowing only the required signal through and ‘gating’ quieter unwanted signals.
Noise gates can be notoriously difficult to use successfully because they tend to ‘trigger’ with some of the unwanted sounds and consume too much studio time with fine adjustment of controls.
The 561 is simple and quick to operate. The main amplifier path is normally active.
A single push-button switch enables the gate. There are minimal controls and ‘at a glance’ led indicators displaying the status of the gate. A red light indicates when the active switch has been pressed. The yellow light shows that the gate is closed. When the gate is triggered by a sound the yellow light goes out and a green light replaces it.
As with other Alice professional equipment the 561 has a super quality low noise signal path with balancing transformers input and output. With the gate switched out the amplifier can provide up to 10dB of audio gain and works brilliantly as an impedance converter maintaining best possible quality from incoming signals.
The balanced transformer input feeds into a system gain control to set the volume level of the signal path.
The side-chain goes via a threshold control to set the gating level and into filters to minimise the effect of unwanted ‘off mic’ sounds.
A ‘release’ control sets the time taken by the gate to return to its ‘off’ state, this has a powerful effect on the sound of the audio signal, from a ‘staccato’ switch to a more relaxed natural sound.
The 561 minimises false triggering by introducing an element of filtering into the operating side-chain; the gating is frequency as well as volume level selective.
The gating process has built-in hysteresis and is highly resistant to any on/off chatter which has been a problem with some gates.
The volume attenuation of the gate when it is active is 55dB
The attack time ‘switch-on time’ is within 1 millisecond and the release time ‘switch-off time’ is adjustable with the ‘release’ control from a minimum of about 1 millisecond up to 20 milliseconds.