Mark Levinson No 332, No 331, No 333 Owners manual

Operating Manual

Mark Levinson

Nº 333 Nº 332

Nº 331

Dual Monaural

Power Amplifiers

Madrigal Audio Laboratories, Inc.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO

NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.

The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance.

Marking by the “CE” symbol (shown left) indicates compliance of this device with the EMC (Electromagnetic Compatibility) and LVD (Low Voltage Directive) standards of the European Community.

The information contained in the manual is subject to change without notice. The most current version of this manual will be posted on our web site at http://www.madrigal.com.

Important Safety Instructions

Please read all instructions and precautions carefully and completely before operating your Mark Levinson® power amplifier.

1. ALWAYS disconnect your entire system from the AC mains before connecting or disconnecting any cables, or when cleaning any component.

2. This product must be terminated with a three-conductor AC mains power cord which includes an earth ground connection. To prevent shock hazard, all three connections must ALWAYS be used.

3. AC extension cords are not recommended for use with this product.

4. NEVER use flammable or combustible chemicals for cleaning audio components.

5. NEVER operate this product with any covers removed.

6. NEVER wet the inside of this product with any liquid.

7. NEVER pour or spill liquids directly onto this unit.

8. NEVER block air flow through ventilation slots or heatsinks.

9. NEVER bypass any fuse.

10. NEVER replace any fuse with a value or type other than those specified.

11. NEVER attempt to repair this product. If a problem occurs, contact your Mark Levinson

12. NEVER expose this product to extremely high or low temperatures.

13. NEVER operate this product in an explosive atmosphere.

14. ALWAYS keep electrical equipment out of the reach of children.

15. ALWAYS unplug sensitive electronic equipment during lightning storms.

retailer.

From all of us at Madrigal Audio Laboratories, thank you for choosing your Mark Levinson 300-series Dual Monaural Power Amplifier.

A great deal of effort went into the design and construction of this precision device. Used properly, it will give you many years of enjoyment.

Table of Contents

Unpacking Your Amplifier ........................................................................... 6

Warm up/break-in period ................................................................................. 6

Placement Considerations ......................................................................... 7

Ventilation ........................................................................................................... 7

Operating Voltage, Nº333 ........................................................................... 8

Nº 333 AC mains maximum current requirements .................................... 8

Nº 333 rear-panel label ............................................................................... 9

Operating Voltage, Nº332 & Nº331 ............................................................ 10

Nº 332 AC mains maximum current requirements .................................. 10

Nº 331 AC mains maximum current requirements .................................... 11

Nº 332/331 rear-panel label ....................................................................... 11

Special Design Features ............................................................................12

Massive Power Supply .......................................................................................12

Balanced design ...............................................................................................12

True Voltage Source........................................................................................... 12

Adaptive Biasing of the Output Stage ........................................................... 13

Extensive Protection .......................................................................................... 13

Front Panel ..................................................................................................15

Rear Panel ..................................................................................................16

Remote turn-on tip polarity ...................................................................... 18

Bridged Operation .................................................................................... 22

Bridging Explained ........................................................................................... 22

Balanced Bridging ........................................................................................... 22

Balanced Bridging Kit ............................................................................... 22

Balanced Bridged Input Connection ..................................................... 23

Single-Ended Bridging ...................................................................................... 24

Single-Ended Bridging Kit ......................................................................... 25

Single-Ended Bridged Input Connection ................................................ 25

Biamplification .......................................................................................... 27

Balanced Y-adapter ................................................................................. 27

Passive biamping wiring diagram ........................................................... 28

Care & Maintenance ................................................................................ 29

U.S. and Canadian Warranty .................................................................... 30

Obtaining Service ...................................................................................... 31

Specifications ............................................................................................ 32

Dimensions: Nº 333 & Nº332 ..................................................................... 33

Dimensions: Nº 331 .................................................................................... 35

Unpacking Your Amplifier

Warning! Under no circumstances should you consider unpacking your

amplifier without adequate assistance, as both personal injury and damage to the product is likely unless you follow the procedures listed below.

The shipping weight of your Dual Monaural Power Amplifier is over 100 lbs. (45 kg)—the Nº333, for example, weighs in at 150 pounds (68 kg)! Any freight this massive must be handled with extreme care to avoid injury. At least two strong people are required to unpack these amplifiers safely.

Included with your new Mark Levinson amplifier is two pairs of knit, white gloves designed to assist you in the initial unpacking and placement of your new purchase. Please accept them as a token of our appreciation for having purchased one of our products.

Caution! Do not attempt to lift your power amplifier from its packing

carton alone. Never attempt to lift your power amplifier while bending from the waist. Always stand as straight as possible and use your leg muscles to lift your amplifier.

After unpacking your power amplifier, keep all packing materials for future transport. In the event that you need to ship your amplifier, only the original,

purpose-designed shipping carton is acceptable. Any other method of shipping this heavy product will almost certainly result in damage to the amplifier—damage that would not be covered by the warranty.

Carefully inspect your amplifier for possible damage due to shipping. If you discover any, contact your Mark Levinson dealer immediately.

Warm up/break-in period Although your Mark Levinson 300-series power amplifier delivers outstanding

performance straight out of the box, you should expect to hear it continue to improve as it reaches its normal operating temperatures and its various components “break-in.” It has been our experience that the greatest changes occur within the first 25-50 hours, but that the amplifier will continue to improve in sound quality for about 300 hours, after which time it remains quite constant.

The only exception to this rule is if power is removed from the unit, allowing it to cool down. In this case you should expect a brief warm-up period before the amplifier’s sound quality is at its best. (Fortunately, you will never have to repeat the full 300 hour break-in period.)

Placement Considerations

PRECAUTION

For your protection, review “Important Safety Instructions” and “Operating Voltage” before you install your amplifier.

Your Mark Levinson 300-series power amplifier is specifically designed to stand on the floor, and must be used as a freestanding unit. In most installations, locating it near the loudspeakers is best. Obviously, this approach minimizes the length of the speaker wires and necessitates longer interconnecting cables from the preamplifier to the power amplifier. The advantage to this strategy lies in the fact that the interconnecting cables carry low-current signals which are more readily transmitted over distances with great accuracy than are the necessarily high current signals required by loudspeakers.

Note that adequate clearance for the AC cord and connecting signal cables must be left behind your amplifier. We suggest leaving at least six inches (15 cm) of free space behind your amplifier so all cables have sufficient room to bend without crimping or undue strain.

If yours is a CE-certified unit (e.g., European market), the amplifier should also be placed in such a way that the power switch on the rear panel is easily accessible. This switch disconnects power from even the supervisory power supply, resulting in effective disconnection of the amplifier from the AC mains. (Note that under these conditions, the amplifier cannot respond to remote-turn-on commands, etc.)

Ventilation As a freestanding unit, your power amplifier normally has no problem with venti-

lation. Regardless of where you choose to locate your amplifier, we advise locating the amplifier well away from sensitive low-level components, typically near the floor. (The massive output currents of which the 300-series amplifiers are capable can generate significant magnetic fields, which could conceivably induce noise in some sensitive components.)

The Nº333 dual monaural power amplifier dissipates approximately 350 watts of energy as heat when “at idle.” The Nº332 and Nº331 dissipate about 325 and 260 watts at idle, respectively. It is therefore normal and perfectly safe for them to run somewhat warm. They do, however, require free air flow around them to allow adequate heat dissipation through air circulation. The top plate and heatsinks of the amplifier must be kept free from any obstruction that would reduce the free flow of air.

Allow at least 4–6 inches above the amplifier and at least 2 inches to sides for adequate ventilation. If the amplifier becomes too warm to touch, the ventilation is inadequate. (Note that your new amplifier is protected against thermal damage. Inadequate ventilation may cause nuisance shutdowns, but should not cause permanent damage to the amplifier.)

Mechanical drawings are included in this manual to facilitate special installations where necessary (see “Dimensions” at the end of this manual).

Operating Voltage, Nº333

Your Mark Levinson Dual Monaural Power Amplifier is characterized by its remarkable ability to pass a musical signal with utter integrity, regardless of how demanding that signal and the loudspeakers used might be. When called upon to do so, your amplifier is capable of generating truly prodigious power levels into virtually any speaker load, on either an instantaneous or a continuous basis.

Depending on the demands placed on the amplifier by your loudspeaker and your listening habits, it is possible (although unlikely) for the capabilities of your electrical service to become the limiting factor in the performance of your system. As a result, the Nº 333 has been designed to be capable of taking advantage of dedicated high current AC mains supplies which cannot limit its performance.

For compatibility with existing household outlets, a standard three prong, 15 ampere plug is provided on the captive, high current AC mains cable. If you decide to use a dedicated, higher-current (30 ampere) line for your Nº 333, the only thing that needs to be changed is the AC plug itself.

Important: When it comes to high current AC wiring such as the Nº 333 is

capable of using, building regulations and electrical codes vary from region to region, and even from one municipality to the next. For this reason, it is impossible for us to anticipate the requirements of your area with regard to high current AC hookups. If you plan to install a dedicated, high current AC line for your Nº 333, please review this section carefully and then contact a local electrical contractor for advice.

Nº 333 AC mains maximum

current requirements

The Mark Levinson Nº 333 amplifiers may be factory-set for 100V, 120V, 200V, 210V, 220V, 230V or 240V AC mains operation at either 50 or 60Hz, based on the country for which they are manufactured. Depending on local electrical codes and regulations, the plug on the supplied AC input module may need to be replaced by a local, licensed electrical contractor. The maximum current requirements (in amperes) at these various voltages under various test conditions are listed in the table shown below. (Note that only 230V units are sold in the Euro-

pean Union countries, per CE requirements.)

100V 120V 200V 210V 220V 230V 240V

Off .1 .09 .05 .047 .045 .043 .042 Standby 2.04 1.70 1.02 .971 .927 .887 .850 On, at idle 3.49 2.91 1.75 1.66 1.59 1.52 1.46 300w @ 8Ω* 18.48 15.4 9.24 8.80 8.40 8.03 7.70 600w @ 4Ω* 31.9 26.6 15.9 15.2 14.5 13.9 13.3 1200w @ 2Ω* 54.2 45.2 27.1 25.9 24.7 23.6 22.6 * power ratings are continuous (rms) with less than 0.5% THD, from 20-20,000 Hz.

It is important to understand that these are worst-case requirements under severe test conditions, which are extremely unlikely to be encountered in normal use.

The power demands that a single Nº 333 might conceivably make when being used to reproduce music with actual loudspeakers are substantially lower, safely within the normal abilities of 100V and 120V, 15 ampere lines. Still, for the best possible performance with extremely difficult loads, we recommend installing a dedicated AC line for the amplifier with 30-ampere capability.

The operating voltage of the Nº 333 cannot be changed by the user, and any attempt to do so will void the warranty. If you need to change the operating voltage of your Nº 333 power amplifiers, or if the voltage indicated on the rear panel label is not available in your area, contact your Mark Levinson dealer for assistance.

Nº 333 rear-panel label

DUAL MONA URAL PO WER AMPLIFIER Nº 333

Operating Voltage, Nº332 & Nº331

Depending on the demands placed on your amplifier by your loudspeaker and your listening habits, it may use a significant portion of the total current capability of a standard, 15 ampere household AC mains circuit. Fortunately, most installations do not require special attention be paid to the AC mains service. If you have multiple, powerful amplifiers such as you new Mark Levinson amplifier, or other appliances on the same circuit that use significant current, you may want to consider having a dedicated AC line installed for your home entertainment system.

For compatibility with existing household outlets, a standard three conductor, 15 ampere, IEC-standard, detachable AC mains cable is provided for use with your amplifier.

Nº 332 AC mains maximum

current requirements

Mark Levinson power amplifiers may be factory-set for 100V, 120V, 200V, 210V, 220V, 230V or 240V AC mains operation at either 50 or 60Hz, based on the country for which they are manufactured. Depending on local electrical codes and regulations, the plug on the supplied AC input module may need to be replaced by a local, licensed electrical contractor. The maximum current requirements at these various voltages under various test conditions are listed in the tables shown below. (Note that only 230V units are sold in the European Union countries, per

CE requirements.)

100V 120V 200V 210V 220V 230V 240V

Off .1 .09 .05 .047 .045 .043 .042 Standby 2.04 1.70 1.02 .971 .927 .887 .850 On, at idle 3.24 2.70 1.62 1.54 1.47 1.41 1.35 200w @ 8Ω* 12.8 10.7 6.38 6.07 5.80 5.54 5.31 400w @ 4Ω* 21.8 18.2 10.9 10.7 9.89 9.46 9.06 800w @ 2Ω* 37.8 31.6 18.9 18.0 17.2 16.5 15.8 * power ratings are continuous (rms) with less than 0.5% THD, from 20-20,000 Hz.

Nº 331 AC mains maximum

current requirements

100V 120V 200V 210V 220V 230V 240V

Off .1 .09 .05 .047 .045 .043 .042 Standby 1.08 0.90 0.54 0.52 0.49 0.47 0.45 On, at idle 2.60 2.20 1.32 1.26 1.20 1.15 1.10 100w @ 8Ω* 7.32 6.10 3.66 3.48 3.33 3.20 3.05 200w @ 4Ω* 12.4 10.4 6.20 5.90 5.63 5.40 5.17 400w @ 2Ω* 21.5 18.0 10.8 10.3 9.80 9.40 8.98

* power ratings are continuous (rms) with less than 0.5% THD, from 20-20,000 Hz.

It is important to understand that these are worst-case requirements under severe test conditions, which are extremely unlikely to be encountered in normal use. The power demands that a single amplifier might conceivably make when being used to reproduce music with actual loudspeakers are substantially lower. Still, for the best possible performance with extremely difficult loads, we recommend installing a dedicated AC line for your amplifier.

The operating voltage of your amplifier cannot be changed by the user, and any attempt to do so will void the warranty. If you need to change the operating voltage of your power amplifiers, or if the voltage indicated on the rear panel label is not available in your area, contact your Mark Levinson dealer for assistance.

Nº 332/331 rear-panel label

DUAL MONA URAL PO WER AMPLIFIER Nº 333

Special Design Features

Congratulations on your purchase of a Mark Levinson Nº 300-series Dual Monaural Power Amplifier. While your new amplifier is straightforward in its everyday use, it includes several design features which are responsible for its outstanding performance. In particular, your new Dual Monaural power amplifier defies the accepted wisdom that it is impossible to design a large, powerful amplifier that also has all of the finesse of the finest smaller amplifiers. A few of the technical highlights that make this possible are given below.

Massive Power Supply Each Mark Levinson 300-series amplifier includes two large, completely indepen-

dent power supplies—one for each channel. Each supply includes a high capacity, low noise toroidal transformer, and two large, low ESR capacitors in each channel. Since these are true, dual monaural designs, each channel has its own dedicated power supply. Specifically, the amplifiers use:

Nº 333: two 2450 VA transformers four 50,000 µF capacitors Nº 332: two 1338 VA transformers four 50,000 µF capacitors Nº 331: two 801 VA transformers four 44,000 µF capacitors

Heavy oxygen-free copper bus bars enhance the efficiency of power distribution within the amplifier and eliminate variances introduced by the wiring harnesses, etc. more commonly found even in high performance amplifiers. High frequency power supply bypass is accomplished on individual PC boards by five components of several film types. The resulting uniformly low power supply impedance seen by the various circuits within the amplifier lays the foundation for both the massive power and the extraordinary finesse that characterizes the 300-series.

Balanced design A truly balanced input topology eliminates the need for an input buffer amplifica-

tion stage and allows the first stage differential amplifier to be driven directly by the source. Matched impedances are presented to the source and both signals travel through identical circuit paths.

Painstaking attention to layout of the amplifier was essential to minimize magnetic field distortions possible with such a massive power delivery system, including careful mirror-imaging of circuits to cancel magnetic fields. A balanced input signal remains balanced throughout the voltage gain stages. Rejection of common mode noise and distortion is achieved in the final, current gain stage.

True Voltage Source The 300-series power amplifiers operate as virtually perfect textbook cases of a

“voltage source.” This is to say that they will maintain whatever the appropriate voltage might be at any moment (given the demands of the music, and within the rated voltage output of the amplifier) without any particular regard for the current demands of the loudspeaker.

Because of this “voltage source” characteristic, the 300-series amplifiers double their power output every time the loudspeaker impedance is cut by half. For ex-

ample, the Nº333’s continuous rated power is 300 watts per channel at 8Ω; 600 watts per channel at 4Ω; 1200 watts per channel at 2Ω—assuming the electrical circuit in the wall can support these extraordinary power levels. A continuous 2Ω

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