3 4 | Manley Labs Manley Massive Passive Stereo Tube Equalizer

THE FRONT PANEL

	22 ± 1K		82 ± 3K9		220 ± 10K		560 ± 27K
BOOST	SHELF	BOOST	SHELF	BOOST	SHELF	BOOST	SHELF
	OUT		OUT		OUT		OUT
CUT	BELL	CUT	BELL	CUT	BELL	CUT	BELL

			22 - 1K		82 ± 3K9		220 ± 10K		560 ± 27K
		BOOST	SHELF	BOOST	SHELF	BOOST	SHELF	BOOST	SHELF
			OUT		OUT		OUT		OUT
	POWER
IN	IN	CUT	BELL	CUT	BELL	CUT	BELL	CUT	BELL

GAIN

0	20		0	20		0	20		0	20	-6	+4		-6	+4		0	20		0	20		0	20		0	20
	DB			DB			DB			DB								DB			DB			DB			DB
BANDWIDTH			BANDWIDTH			BANDWIDTH				BANDWIDTH	12K	9K	LOW	12K	9K		BANDWIDTH			BANDWIDTH			BANDWIDTH			BANDWIDTH
											18K	7K5	PASS	18K		7K5
											OFF	6K		OFF		6K
FREQUENCY			FREQUENCY			FREQUENCY				FREQUENCY							FREQUENCY			FREQUENCY			FREQUENCY			FREQUENCY
100	150		390	560		1K	1K5		2K7	3K9							100	150		390	560		1K	1K5		2K7	3K9
100	220		390	820		1K	2K2		2K7	5K6	39	68	HIGH	39	68		100	220		390	820		1K	2K2		2K7	5K6
68		330	270	1K2	680		3K3	1K8		8K2	22	120	PASS	22		120	68	330	270		1K2	680		3K3	1K8		8K2
68		330	270	1K2	680		3K3	1K8		8K2			PASS				68	330	270		1K2	680		3K3	1K8		8K2
											OFF	220		OFF		220
47		470	180	1K8	470		4K7	1K2		12K							47	470	180		1K8	470		4K7	1K2		12K
33		680	120	2K7	330		6K8	820		16K							33	680	120		2K7	330		6K8	820		16K
22	1K		82	3K9		220	10K		560	27K		MASSIVE PASSIVE					22	1K		82	3K9		220	10K		560	27K
												STEREO EQUALIZER

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1)The Power Switch: First things first, turn it clockwise to power up the unit. There is no "power on LED", instead you can use any of the Boost / Off / Cut switches in Boost or Cut and they light immediately with power on. There is a "warm-up" circuit that forces the unit into "Bypass" for about 20 seconds, to prevent big thumps from hitting your speakers. This also prevents the blue LEDs that indicate "EQ IN" from lighting up for that 20 seconds. This is not a total hardwire bypass - if power is not on, the unit will not pass audio. At trade shows, we have seen a few people turn the "Power Switch" by accident, perhaps thinking it was a tone control. Not knowing, there is a "warm-up" circuit, and seeing no blue light action, they thought they may have broken the unit. The lack of a "power LED" is just one of the deliberate ideosyncracies. 4 reasons: there wasn't a great place to put one, it was redundant with 16 boost/cut LEDs (we were laughing at other panels with dozens of lit LEDs and a fast turn-on LCD screen also sporting a big power LED), and this unit is meant for professionals that we assume can plug in a piece of gear, see (or feel) the switch and turn it on, and it may annoy those who want all gear to be just "normal" ;-)

2)EQ IN buttons: Push to activate the EQ circuits. The buttons glow blue when EQ is IN including the Filters and Gain Trims. The "warm-up" circuit prevents both EQ to be IN and the buttons from lighting when it first gets powered up. In "bypass" (un- lit) the tubes are not in circuit but the input amplifier and balanced output transformer are in circuit. Yes, real blue LEDs.

3)Gain Trims: Intended to help match levels between "Bypass" and "EQ IN" modes so that the EQ effect can be more accurately judged. It is difficult to compare if the level jumps up or down and easy to prefer EQ when mostly it is just louder. These trims only have a small range of -6 to +4 dB of gain. With drastic EQ there may not be enough range to match levels but with drastic EQ this kind of comparison is of little use. The range is small to allow easier and finer adjustments.

4)Low Pass Filters: They pass lows and chop highs. There is a separate filter for each switch setting and they only share the switch and one resistor. The filters are entirely passive and "inserted" between the boost sections and cut sections.

The 18kHz filter is probably most useful for warming up digital. It seems to remove some irritating super-sonic noise associated with digital to analog converters. It is designed as a modified eliptical filter down 60dB one octave up (36kHz) on paper but in real life "only" drops about 40 dB. It is flat within 0.5dB up to 16kHz then very steeply drops. It is sonically subtle. 12kHz position can be considered general purpose hiss killing. It is also very flat up to 11kHz and drops at 30 dB/octave. 9kHz, 7.5kHz & 6 kHz. These are intended for more creative sound sculpting than as utility filters. They have a 1.5 to 2 dB bump or boost right before they cut at 18dB/octave. This helps compensate for the percieved loss of highs while still allowing deep HF cuts. This gives them a little color and edge as opposed to just dullness. You may find they help remove some of that buzzy super high distortion of cranked guitar rigs as well as help some synth and bass sounds. They are also intended to help with "effects" such as "telephone sound" and vintage simulations and for some techno, rap and industrial style music.

5)High Pass Filters: They pass highs and chop lows. There is a separate filter for each switch setting and they only share the switch and one resistor. The filters are entirely passive and "inserted" between the boost sections and cut sections. They are all 18dB/octave (most modern filters are 12), with no bumps and no resonances. We use a large, low DCR, custom inductor. The 22Hz is very subtle and is designed to remove sub-sonic frequencies that may have been boosted by previous EQ. Most signal below 25Hz is only good for testing or messing up sub-woofers. You may not hear the effect in the studio, but often you can see it on the meters. Now that sub-woofers are becoming common in autos and consumer systems, we are hearing more complaints of excess lows and LF garbage. This filter is in response to these concerns and requests from mastering engineers. The 39Hz filter can be used similarly, but may be audible with some material. This filter, as with the others, can be used with the normal boost/cut sections for a more tailored low EQ. This can allow bigger and more effective LF boosts while minimising the side-effects of excessive woofer excursions and unwanted audible LF noise like air conditioner or subway rumble.

The 68Hz filter is also general purpose and ideal for most vocals and pop removal. Also good in combination with shelves. 120 and 220Hz filters are intended for garbage removal, sonic sculpting, and effects. 120 is useful for some vocals. The 220 is for some close miked hi-hats and percussion instruments. Yup, 220Hz tends to be drastic and only occasionally valuable.

Check out the curves on page 16 for a little more detail on these filters.

Manley Massive Passive Stereo Tube Equalizer specifications

The Manley Massive Passive Stereo Tube Equalizer stands as a hallmark in the world of high-end audio processing, renowned for its unique design and exceptional sound character. This equalizer embodies the brand's commitment to quality and sonic integrity, making it a coveted piece of equipment for professional audio engineers and enthusiasts alike.

One of the standout features of the Massive Passive is its all-tube signal path. Utilizing vacuum tubes, the equalizer imparts a warm, rich tone that is often described as “musical”. This tube-based design works in conjunction with a passive equalization topology, which means that rather than boosting frequencies through active components, it relies on a network of inductors and capacitors, preserving the audio signal's purity while allowing for versatile tone shaping.

The Massive Passive is equipped with a wide range of frequency bands, allowing engineers to tailor their sound precisely. It features a dual-channel configuration with controls for both left and right channels, enabling stereo adjustments that maintain phase coherence. Each channel includes numerous frequency selections across both low and high ranges, granting access to numerous filtering options that highlight or attenuate specific frequencies as required.

An essential aspect of the Massive Passive is its innovative design, characterized by high-quality components, including Manley’s custom-designed transformers and circuit boards. These components are engineered to minimize noise and distortion, ensuring that the equalization process does not compromise the integrity of the source material. Users can enjoy the convenience of both low-frequency and high-frequency adjustments, as well as the ability to boost or cut with a substantial range, from a subtle touch to significant alterations.

One of the intelligent aspects of the Massive Passive is its 'bypass' feature. This allows users to seamlessly compare the processed sound against the original audio, making it easier to make informed decisions on adjustments. The build quality of the unit is also remarkable, showcasing a robust chassis that is both aesthetically pleasing and incredibly durable, signifying Manley Labs’ attention to detail.

Ultimately, the Manley Massive Passive Stereo Tube Equalizer encapsulates the essence of analog warmth and precision in audio processing. By integrating sophisticated engineering with user-friendly controls, it provides both professional and home studios with the tools necessary to achieve that sought-after sonic richness, making it a top choice among discerning audio professionals.