Tapco manual SQ2 Features, Front Panel Features, Gate, Compressor/Limiter

SQ•2 Features

					3		4		CHANNEL 1	6			8	10					11																	12
1		GATE							5							GAIN REDUCTION(dB)							GATE							CHANNEL 2						AIR
							COMPRESSOR / LIMITER								AIR													COMPRESSOR / LIMITER
	-	-30	-15	-20	-10	2	2.5	10	50	0.5	1	-6	0			30	20	15	10 6	4	2	1	-30	-15	-20	-10	2	2.5	10	50	0.5	1	-6	0
		50			0		5		100	0.3			+6			CH 1							-50			0		5		100	0.3			+6		ON
					+10																					+10
	-70		0 -30					8 1	150	0.1		2 -14	+14										-70	0 -30					8 1	150	0.1		2 -14	+14
						1.5										CH 2											1.5
																	CH 1				CH 2
	OFF		+10	-40	+20	1	LIM	0.1	200	50ms	3	-20	+20	OFF	FULL	AUTO		IN		AUTO		IN	OFF	+10	-40	+20	1	LIM	0.1	200	50ms	3	-20	+20	OFF	FULL
		dBu			dBu		n:1		ms	sec			dB										dBu			dBu		n:1		ms	sec			dB
			CLOSE						AUTO				CHAN 1											CLOSE						AUTO				CHAN 2		POWER
									IN/OUT				IN/OUT																	IN/OUT				IN/OUT
	THRESHOLD			THRESHOLD			RATIO	ATTACK		RELEASE			OUTPUT		LEVEL								THRESHOLD		THRESHOLD			RATIO	ATTACK		RELEASE			OUTPUT		LEVEL
			2						7				9

BY

SQ•2

FRONT PANEL FEATURES

The controls for Channels 1 and 2 are the same, so these descriptions apply to both channels.

GATE

1. THRESHOLD

Use this control to set the point where the gate begins to attenuate the signal. It ranges from OFF (no gating action) to +10 dBu.

When the signal drops below the level indicated by the knob setting, the gate “closes” and the adaptive gain reduction of the downward expander kicks in.

5. ATTACK

This control determines how fast the compressor reacts once the threshold has been exceeded. It ranges from 0.1 ms (milliseconds) to 200 ms.

If you want to use the compressor as a limiter, set the ATTACK knob to its lowest setting (0.1 ms). This way the limiter quickly catches the fast transients before they can clip the signal.

Otherwise, set the ATTACK knob to a somewhat higher setting to avoid the “pumping” effect you sometimes hear when a compressor is triggered on and off frequently.

2. CLOSE LED

This LED lights when the signal drops below the threshold and the gate “closes.” It indicates that the gate is working.

COMPRESSOR/LIMITER

3. THRESHOLD

This control is used to set the point where the compressor begins to attenuate the signal. It ranges from –40 to +20 dBu.

As the input level increases, the output level increases linearly until the threshold point is reached. When the signal rises above the level indicated by the THRESHOLD knob setting, the compressor begins to act on the signal and the output level no longer increases linearly. Instead it increases at a reduced rate determined by the ratio setting.

4. RATIO

The RATIO control determines the change in output level as a function of the change in input level, once the threshold has been crossed. It ranges from 1:1 (off) to LIM (full compression), where the compressor acts as a peak limiter and the signal stops increasing once it crosses the threshold.

As an example of how the compressor works, if the RATIO is set to 2 (2:1), an increase in the input level of 10 dB results in a 5 dB increase in the output level (assuming the input signal is above the threshold level).

6. RELEASE

This determines how fast the compressor turns off once the signal falls below the threshold. It ranges from 50 ms to 3 seconds.

Again, set the RELEASE knob to its lowest setting (50 ms) when using the compressor as a limiter. Otherwise, setting the RELEASE knob to a higher setting helps smooth out the compressor’s action, making it less audible.

7. AUTO IN/OUT

Push this switch in to bypass the ATTACK and RELEASE controls and let the SQ•2 automatically determine the optimum settings, depending on the type of signal present. When the AUTO button is pushed in, the AUTO LED below the GAIN REDUCTION Meters lights.

8. OUTPUT

This control provides “make-up gain” for the compressed signal. It ranges from –20 to +20 dB. Use this control to compensate for the loss of gain caused by the action of the compressor.

For example, if you are seeing an average gain reduction on the meter of about 6 dB, turn the OUTPUT control up to +6 dB to make up for it.

9. CHAN IN/OUT

This is a “bypass” switch that effectively disables the gate and compressor circuits. You can use this switch to compare the processed signal to the unprocessed signal. When the CHAN IN/OUT button is pushed in, the IN LED below the GAIN REDUCTION Meters lights.

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