Mackie 1642-VLZ3 50. AUX SENDS SOLO and LED, STEREO RETURNS (LEVEL), 52. TO AUX 1 and TO AUX, 53. MAIN MIX TO SUBS (for RETURN 3), 54. 1–2/3–4(for RETURN 3)

VLZ3-		50. AUX SENDS SOLO and LED
		In live sound situations, AUX SEND [6] outputs 1
		and 2 are likely to feed your stage monitors. You’ll want
1642		to check the mix you’re sending them, and that’s what
		these two buttons are for. (AUX 3 and 4 have no such
		switch.) Beside each switch is a green LED that, just
		like the channel’s –20 LED, helps you find the rogue
		SOLO switch.
		The only thing different about AUX SENDS SOLO is
		that it’s not really PFL (pre-fader listen), and it’s not
		really SIP (solo-in-place), it’s actually AFL (after-fader
		listen.) Read on:
		In the NORMAL (AFL) position of the MODE [44]
		switch, you’ll get AUX SEND 1’s solo signal, post-AUX
		SENDS [49] master level, in the left side of the control
		room, headphones, and meters, and AUX SEND 2 on
		the right side. (If you ever use AUX 1 and 2 to create a
		stereo monitor mix, you’ll understand why.)
		In the LEVEL SET (PFL) position of the MODE
		switch, you’ll get the signal dead-center, but still post-
		AUX SENDS master level.
		51.	STEREO RETURNS (LEVEL)
		These four controls set the overall level of effects
		received from the STEREO RETURN [7] input jacks.
		These controls are designed to handle a wide range of
		signal levels — each knob goes from off, to unity gain at
		the detent, to 20 dB gain fully clockwise, to compensate
		for low-level effects. Signals passing through these con-
		trols proceed directly to the MAIN MIX [37] fader, with
		exceptions that we’ll discuss in a moment.
		Typically, these knobs can just live at the center
		detent, and the effects device’s output control should
		be set at whatever they call unity gain (check their
		manual). If that turns out to be too loud or too quiet,
		adjust the effects device’s outputs, not the mixer. That
		way, the mixer’s knobs are easy to relocate at the center
		detent.
		52. TO AUX 1 and TO AUX 2
		If you want to add reverb or delay to the stage monitor
		mixes, these are the knobs for you. Operating indepen-
		dently of their respectively numbered STEREO RE-
		TURNS [51] level controls, these knobs are the same as
		the AUX 1 [35] and 2 knobs in the channel strip.
		These two knobs feed STEREO RETURN signals to
		their respective AUX SEND [6] outputs: TO AUX 1 feeds
		STEREO RETURN 1 to AUX SEND 1 [49] master, and
		TO AUX 2 feeds STEREO RETURN 2 to AUX SEND 2
		master. They are off when turned fully down, deliver
		unity gain at the center detent, and provide up to 15 dB
		of gain turned fully up. STEREO RETURN 3 and 4 have
		no such knobs.
	22		1642-VLZ3

53. MAIN MIX TO SUBS (for RETURN 3)

With this switch up, STEREO RETURN 3 behaves like all the others — it delivers a stereo signal, regulated by its level knob, to the main mix. When you engage this switch, the signals are removed from the main mix buses and sent to the 1-2/3-4 switch [54], which diverts the signal once more. We’re not finished. Please read on:

54. 1–2/3–4 (for RETURN 3)

If the MAIN MIX TO SUBS [53] switch is disengaged, the 1–2/3–4 switch does absolutely nothing. Let’s now assume it’s engaged. STEREO RETURN 3’s stereo signal will not be sent to the main mix, but to SUBGROUP FADERS [38] 1 and 2 (this switch up) or 3 and 4 (this switch down).

Let’s say you’ve made a stereo drum submix on SUBGROUP FADERS 1 and 2, so you can ride those two faders instead of the seven channels that the drums came from. SUBGROUP FADER 1 has its ASSIGN TO MAIN MIX [39], left button engaged and SUBGROUP FADER 2 has its ASSIGN TO MAIN MIX, right button engaged, blending the drum submix back into the main mix. The drum channels are also sending signals to your reverb via the AUX SENDS [6], and the reverb outputs are patched into STEREO RETURN 3 [7]. So far so good.

Even though you could send STEREO RETURN 3 directly to the main mix (MAIN MIX TO SUBS [53] switch up), you don’t want to. Instead, engage the MAIN MIX TO SUBS switch and make sure the 1–2/3–4 switch is up. Now the reverb return will be blended into the drum submix, and as you ride those two faders, the reverb level will follow.

Why do we want that? Because if you had just sent the reverb directly to the main mix (MAIN MIX TO SUBS switch up) and you did a drum fade-out using SUBGROUP FADERS 1 and 2, the “dry” signals would fade out, but the “wet” signals would keep on singing. All you would hear is the drum reverb (the “wet”), and none of the original drum signals (the “dry”). That’s because the reverb is being fed by the channel’s AUX sends, and they have no idea that you’ve pulled down the SUBGROUP FADERS. That’s why we threw in these switches.