Mark Levinson 28 Owners Manual

Operating Manual

Mark Levinson

Nº28

Preamplifier

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 Nº28 Preamplifier.

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® retailer.

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.

From all of us at Madrigal Audio Laboratories, thank you for choosing the Mark Levinson® Nº28 Preamplifier.

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

Front panel ...................................................................................................1

Rear panel ................................................................................................... 2

Unpacking and placement .......................................................................4

Unpacking .............................................................................................. 4

Placement ............................................................................................. 4

Ventilation ..............................................................................................4

Voltage selection ........................................................................................5

PLS-228 bottom-panel label .......................................................... 5

Set-up and installation ................................................................................6

Connectors and cables ....................................................................... 6

Internal adjustments: line gain ............................................................. 6

Line gain settings ............................................................................ 6

Internal adjustments: phono gain ....................................................... 6

Phono gain settings (high-gain option) ....................................... 6

Phono gain settings (low-gain option) ......................................... 6

Internal adjustments: cartridge loading ............................................. 7

Cartridge loading settings (high-gain option) ............................ 7

Cartridge loading settings (low-gain option) .............................. 7

Internal adjustments: optional load terminals ................................... 7

Terminating the optional load ...................................................... 7

Internal adjustments: varying the input capacitance ...................... 8

Making the internal adjustments ......................................................... 8

Nº28, internal adjustments ............................................................. 8

Power connection and system activation ......................................... 9

AC power cord polarity ................................................................. 9

Care and maintenance ...........................................................................10

Specifications ............................................................................................11

Phono section ...................................................................................... 11

Line section .......................................................................................... 11

Dimensions................................................................................................. 12

Dimensions, Nº28, top view.......................................................... 12

Dimensions, Nº28, side view ......................................................... 12

Dimensions, PLS-228, top view ..................................................... 13

Dimensions, PLS-228, side view .................................................... 13

PHONO/

AUX 2

TUNER

AUX 1

INPUT SELECTOR MONITOR SELECTOR RECORD SELECTOR OUTPUT LEVEL

TAPE 1

TAPE 2AUX 3

TAPE 1

MADRIGAL AUDIO LABORATORIES

Nº 28

PREAMPLIFIER

INPUT

MONITORDEFEATTAPE 2

OFF

1 2 3 4

Front panel

1 INPUT SELECTOR

Selects one of the seven inputs: CD, TUNER, PHONO/AUX 1, AUX 2, AUX 3, TAPE 1, or TAPE 2.

2 RECORD SELECTOR

Selects between the program source (selected via the INPUT SELECTOR), and either of two tape monitor inputs (selected via the MONITOR SELECTOR).

In the DEFEAT position, the tape outputs are disconnected.

In the INPUT position, the tape outputs are connected while still monitoring the selected source.

In the MONITOR position, the selected tape machine can be monitored without affecting the signal at the tape outputs.

Note: Because of the switching arrangement employed in the Nº28, we recommend that while making a critical recording you don't operate the RECORD SELECTOR switch.

If you wish to monitor the signal from tape, set the RECORD SELECTOR to MONITOR and use your tape machine's monitor switch to switch between input and tape.

3 MONITOR SELECTOR

When the RECORD SELECTOR is in the MONITOR position, this selects between the TAPE 1 and TAPE 2 inputs.

4 OUTPUT LEVEL

Adjusts volume at the main outputs.

The OUTPUT LEVEL control doesn't affect the tape outputs.

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