Q2 Audio Compex F760X-RS, Руководство пользователя

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The Expander/Gate Section: Expand Mode
i). in the ‘Expand’ mode the low level gain reduction slope is of the order of 2:1. The control is ‘feed forward’ so that the
expander side-chain is arranged to monitor the input signal prior to the F760 input attenuators. The meter will indicate gain
reduction when it operates and at the same time the green indicator will flash to differentiate it from high level gain reduc -
tion (limiting/compression).
j.) To set up the Expander mode it is probably best to switch the compressor section to 1:1 and back off the main input at -
tenuator until Pk. Limiting it only just operating.
k). Switch the Expand/Gate switch to ‘Expand” and the Expand Attack to ‘M’. With the Expander Threshold fully anti-clock -
wise (shut – i.e. infinitely high) adjust the Expander Range control so that the maximum amount of low level attenuation is
set-up on the meter (i.e. 20dB) and the green indicator will be on.
l). Now open the Threshold control until the meter and light indicate no gain reduction when signal is present but with fast
expander Release attenuates quickly on unwanted noise/crosstalk. Thus the threshold is adjusted so that it is just open to
allow all wanted signal through, but is closing rapidly during pauses. If it is operating on noise and crosstalk there will be
no modulation effect and fastest release (attenuate time) can be sued (see Expander/Gate – Considerations). The open
speed will be determined by the Attack control switch.
m). Should the maximum attenuation range not be reached during pauses, this will be because the expander is being held
open to some degree on input noise (see Expander/Gate – Considerations). One must either accept the limited range
possible or turn back the threshold pot slightly so some of the wanted signal may now begin to be expanded; release and
attack may need adjustment to avoid modulation effects. The alternative is to use the GATE position.
n). Having established the Expander mode satisfactorily switch it ‘out’ re-establish the compression section by selecting
the ratio and increasing the input attenuator to give compression required. Then switch the Expand mode to ‘In’. Make any
final fine adjustments.
The Expander/Gate Section: GATE MODE
o). the Gate position provides low level gain reduction at a slope of 20:1. IN thie mode the control side-chain in in a ‘feed -
back’ arrangement deriving its sense-data frm the F760 output. Thus the Compressor/limiter sections myst be established
and fully operating whilst the Gate Threshold if found.
p). Having set up the Compressor/Limiter sections switch the F760bypass ‘In/Out’ switch to ‘Out’ so that no signal is going
through the unit.
q). Switch the Expander/Gate switch to the Gate mode. The green light will come on and the meter indicate gain reduction
providing the Range control is not on ‘0’. Adjust the Range control for the maximum amount of low level gain reduction
required ( i.e. -20 or whatever).
r). Switch in the F760 and adjust the Threshold of the Gate along with the Release and Attack controls so that it is closing
quickly on noise, yet fully open in the presence of wanted signal. (see EXPANDER/GATE - Considerations)
STEREO OPERATION
s). The Compressor section and Expander/Gate section are matched for stereo in stereo units. The ‘Stereo-Link’ switch
links the relative control voltages so that gain reduction is always identical on both channels thus obviating and image
shift. For simplicity it is best to set-up controls identically on both channels – setting each channel prior to throwing the
Stereo switch ‘IN’.
t.) The Peak Limit sections are not linked and will continue to function independently; momentary attenuation of transients
will not be appreciably noticeable with regard to image shift.