Madrigal Imaging Mark Levinson, Dual Monaural Power Amplifier User Manual

Operating Manual

Mark Levinson

Nº29

Dual Monaural

Power Amplifier

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.

Important safety instructions

Please read all instructions and precautions carefully and completely before operating your Nº 29 Dual Monaural 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 is equipped 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. If your electrical outlets will not accept this type of plug, an adapter may be purchased. If an adapter is necessary, be sure it is an approved type and is used properly, supplying an earth ground. If you are not sure of the integrity of your home electrical system, contact a licensed electrician for assistance.

3. AC extension cords are not recommended for use with this product. If an extension cord must be used, be sure it is an approved type and has sufficient current-carrying capacity to power 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® dealer.

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.

Thank you for choosing the Mark Levinson® Nº29 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 and placement .......................................................................1

Unpacking .................................................................................................1

Placement ................................................................................................. 1

Ventilation ................................................................................................. 1

Custom installations.................................................................................. 1

Voltage selection ........................................................................................ 2

Figure 1: Rear-panel label .................................................................... 2

Signal connections ..................................................................................... 3

Connectors ............................................................................................... 3

Cables........................................................................................................ 3

Connection methods and operating modes ....................................... 3

Single-ended normal (non-inverting) operation................................... 3

Figure 2: Connections for single-ended normal (non-inverting)

operation ......................................................................................... 3

Figure 3: Female input connector ....................................................... 4

Single-ended inverting operation .......................................................... 4

Figure 4: Connections for single-ended inverting operation ........... 4

Balanced normal (non-inverting) operation ......................................... 5

Figure 5: Connections for balanced normal (non-inverting)

operation ......................................................................................... 5

Speaker connections .................................................................................6

Speaker cables ......................................................................................... 6

Lug connection ........................................................................................ 6

Figure 6: Spade and hook lugs ............................................................ 6

Pigtail connection .................................................................................... 6

Figure 7A: Pigtail connection ............................................................... 6

Figure 7B: Pigtail connection ............................................................... 7

Figure 7C: Pigtail connection .............................................................. 7

Connecting the speakers ........................................................................ 7

Power connection ....................................................................................... 8

Connecting the AC power cord ............................................................ 8

Figure 8: AC power cord polarity ........................................................ 8

Performance tips ...................................................................................... 8

Protection circuitry ................................................................................... 8

Bridged operation ....................................................................................... 9

Balanced bridged operation.................................................................. 9

Figure 9: Connections for balanced bridged operation ................. 9

Figure 10: Balanced bridging cable ................................................. 10

Single-ended bridged operation ......................................................... 10

Figure 11: Connections for single-ended bridged operation ........ 10

Figure 12: Single-ended bridging cable ........................................... 11

Care and maintenance ...........................................................................12

Cleaning .................................................................................................. 12

Fuses ......................................................................................................... 12

Specifications ............................................................................................13

Dimensions.................................................................................................14

Figure 13A: Dimensions, Nº29, top view ............................................ 14

Figure 13B: Dimensions, Nº29, side view............................................ 14

Unpacking and placement

Unpacking

PRECAUTION

Placement

Ventilation

Unpack your Nº29 amplifier and keep all packing materials for future transport.

To avoid damaging the connectors on input cables attached to the rear panel, NEVER rest the Nº29 on the rear panel, and NEVER tip it back in a way that would put stress on these connectors.

Carefully inspect your Nº29 for damage and flaws. If you find any, see your Mark Levinson dealer immediately.

To keep speaker cables as short as possible, place the Nº29 as close to the loudspeakers as practical.

Place the Nº29 at least three feet from the turntable and preamplifier. Otherwise, the Nº29 may induce hum into these sensitive components.

The Nº29 may be placed in a cabinet or on a shelf, but adequate ventilation must be provided to prevent overheating. The clearance provided by the unit's feet must be maintained to ensure unrestricted air flow across the bottom of the chassis. (Placing the Nº29 on carpeting, for example, may prevent adequate air circulation.) Clearance above the unit must also be maintained to allow air circulation and to prevent heat buildup.

Custom installations

The Nº29 incorporates thermal sensors located near each group of output devices. If the internal heatsink temperature becomes excessive, these sensors will shut off the amplifier before damage results. After a brief cooling period, the amplifier can be reactivated via the front-panel switch. If this occurs regularly during normal use, it's an indication that the ventilation provided for the amplifier is inadequate. If there's adequate ventilation and the problem continues, see your Mark Levinson dealer immediately.

For those involved in custom installations and cabinetry, this information may be useful:

■ All temperature measurements are made at the bottom of the

internal heatsink, 2 inches above the chassis floor.

■ Normal heatsink temperature at idle after warmup with unrestricted airflow at 22°C (72°F) ambient temperature: 35°C (95°F).

■ Maximum permissible heatsink temperature before thermal protection is activated: 80°C (176°F).

Drawings are included in this manual to facilitate special installations and custom cabinetry (see "Dimensions").

PRECAUTION

For your protection, review "Important safety instructions" before you install your Nº29.

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