Input, High Gain - Engl INVADER II Operator's Manual

17 Noise Gate
Press this button to activate an onboard Noise Gate and suppress excess noise in
channel 2, 3 or 4. Control the Noise Gate using the Level Threshold (49) knob on the
back of the amp. The LED above the button lights up to indicate the Noise Gate is
activated. This feature can also be switched via MIDI program change or the ENGL
Custom Z-9 Footswitch.
: The Noise Gate may open up inadvertently
IMPORTANT note; please read and heed
when the Noise Gate is activated, a high-gain channel is selected, and the volume
exceeds the Threshold knob setting. At very high volume and gain settings, this may
generate instant feedback, particularly if your guitar is facing the speakers. Rather
than musical and controlled, this is the shrill, unpleasant and potentially harmful
variety of feedback squealing that sends your audience and fellow musicians packing.
Though the amp is not more susceptible to feedback when the Noise Gate is activated,
the fact that it suppresses extraneous noise means you can't hear those telltale signs
that feedback is swelling and consequently can't take measures to suppress it. For this
reason, make an extra effort to be careful when the Noise Gate is activated: Before
you approach the amp and speaker cabinet with your guitar in hand, turn the guitar's
volume knob to the far left position (to 0 so that no signal is audible) to prevent the
pickups and speakers from interacting!
A tip from the designer:
Noise is a definite no-no in many situations. For example, studio etiquette demands
that you keep a lid on extraneous noise during short breaks. It's in the nature of high-
gain rigs to generate undesirable peripheral noise in overdriven channels. This is
attributable to the physical properties of an amp's constituent components, in
particular its active components. That's right; those cherished tubes are the culprits.
The Noise Gate is a tool that lets you silence this noise during breaks by way of signal
mute circuit. Note that electric guitars pick up interference signals, and these are
amplified tremendously at high gain levels in High Gain mode. The most common
source of noise is 50 or 60 hertz mains hum, particularly when the guitar is positioned
near transformers and power units. Because in worst-case scenarios this humming can
attain extremely high levels, the Noise Gate can hardly distinguish between the
musical signal and noise. This makes it hard to find the right Threshold setting. It is
entirely possible for this humming and other noise to rise to a level that deactivates the
Noise Gate and therefore becomes audible. My advice is to stay as far away from
transformers and power units as space allows.
18 Input
¼" unbalanced input jack. Plug your guitar in here using a shielded cord.
A tip from the designer:
Depending on the type of cord and its shielding, you may occasionally encounter
interference from sources such as radio stations or powerful magnetic fields. When
this occurs, try connecting your guitar to the amp using different cords. What's more,
to minimize signal degradation due to high-frequency loss, use the shortest cords
feasible (as a rule, the shorter the cord, the less susceptible it is to high-frequency
attenuation).
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