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.
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.
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 ...........................................
Unpacking and placement Unpacking PRECAUTION 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.
Voltage selection The Nº29 is factory-set (internally) for 100V, 120V, 200V, 220V, or 240V AC mains operation. Check that the label on the rear panel of the amplifier indicates the correct AC operating voltage for your location.
Signal connections Connectors The Nº29 incorporates RCA-type and XLR-type connectors for audio signal input. The Madrigal-designed RCA-type connectors used for single-ended audio interconnection are a great improvement over ordinary RCAtype connectors. The gold-plated XLR-type connectors employed are of European design, and are made to professional application standards.
Single-ended inverting operation Inverting operation should be used if a phase reversal is required. In this mode of operation, the output signal of the amplifier will be 180° out of phase with the input signal. This may be required if one component in the system inverts the signal and absolute phase at the loudspeaker is desired. For inverting operation, the main output cables of the preamplifier must be connected to the XLR-type inputs on the rear panel of the Nº29.
Balanced normal (non-inverting) operation If your preamplifier is equipped with a balanced main output, it's best to wire the Nº29 for balanced operation, particularly if long cable lengths are required between the preamplifier and the Nº29. (See Figure 3 for the pin assignments of the Nº29's XLR-type inputs.) Connect the XLR-type male line-mount connector to the preamplifier, carefully observing pin assignments.
Speaker connections PRECAUTION NEVER connect the Nº29's output terminals to any device other than a loudspeaker. PRECAUTION NEVER short-circuit the amplifier output terminals. PRECAUTION NEVER connect the left-channel output terminals to the right-channel output terminals. Speaker cables The Nº29 is equipped with gold-plated, high-current, five-way binding posts for output termination to a loudspeaker system.
3. Strip 1/2" of insulation from the speaker cable. 4. Gently slide the (5/8") bare end of the 14-gauge wire into the center of the bare speaker cable (be careful not to spread the individual wires of the speaker cable). 1/2" (12.7mm) Tin Figure 7B: Pigtail connection Speaker cable Solder 5. Solder this connection. A high-wattage soldering gun may be necessary to provide adequate heat. 6. Lightly "tin" the remaining (1/2") bare end of the 14-gauge wire. 7.
Power connection After making your loudspeaker connections, apply power to your preamplifier and allow it to stabilize. (Mark Levinson preamplifiers, for example, require about one minute to stabilize.) Connecting the AC power cord Connect the AC power cord (included in the accessory pack) to the AC connector on the rear panel of the Nº29, then to the AC mains outlet.
Bridged operation When greater power output is desired, the Nº29 may be bridged for monophonic operation into load impedances of at least 2Ω. Note: Make sure the loudspeaker is rated to handle high power levels. For example, a bridged Nº29 driving an 8Ω loudspeaker is capable of delivering 200W RMS. Balanced bridged operation For the best bridged performance, we recommend balanced interconnection. If your preamplifier provides balanced output, follow the steps below.
XLR female line-mount (rear view) 1 2 3 Signal ground (shield) Twisted pair Figure 10: Balanced bridging cable 2 Left-channel XLR male line-mount (rear view) 1 Signal ground (shield) 3 2 Twisted pair 1 Right-channel XLR male line-mount (rear view) 3 2. Connect the bridging cable's male XLR-type connectors to the Nº29's left- and right-channel XLR-type input connectors, taking care to insert the correct cable end into its designated channel. 3.
2. Connect the bridging cable between the left- and right-channel XLR-type input connectors, taking care to insert the correct cable end into its designated channel. You may fabricate such a cable according to Figure 12; it's also available through your Mark Levinson dealer as part of a single-ended bridging kit. Note: If fabricating the bridging cable, be sure to use highquality audio interconnect cable (such as Madrigal HPC).
Care and maintenance Cleaning To remove dust from the cabinet of the Nº29, use a feather duster. To remove dirt and fingerprints, use isopropyl alcohol applied to a soft cloth. Poor connections cause sonic degradation. We recommend, therefore, that you clean all speaker connection with denatured alcohol at least once a year. Consult your Mark Levinson dealer for other ways to optimize connections. Fuses PRECAUTION 12 The Nº29's fuses are located on the rear panel.
Specifications The correlation between published specifications and sonic quality is unreliable. A list of numbers reveals virtually nothing. All technical measurements must be subject to qualitative as well as quantitative interpretation. Measurements of the Nº29 yield excellent results by any standards. However, only those specifications that apply to the actual operation of the amplifier are included here.
Dimensions 1/8" (3.2) Figure 13A: Dimensions, Nº29, top view 1-3/4" (44.5) 4-29/64" (113.1) 17-1/2" (444.5) 1-7/16" TYP. (36.5) 17-1/4" (438.2) 1" TYP. (25.4) 1-9/16" (39.7) 1-3/32" (27.5) 2-53/64" (71.8) 4-1/8" (104.8) 3/8" (9.5) 14-3/16" (360.4) 29/32" (23.0) 21/32" (16.7) Figure 13B: Dimensions, Nº29, side view 1-7/16" (36.5) 5-7/8" 5-1/4" (174.8) (133.4) 13/16" 7/64" (20.7) (2.8) 14 1-5/8" (41.3) 5/8" (15.9) 3-45/64" (94.1) 6-11/16" 169.9) 2-21/64" (59.
MADRIGAL AUDIO LABORATORIES 2081 South Main Street, P.O. Box 781 Middletown, Connecticut 06457 USA Telephone: (203) 346-0896 Fax: (203) 346-1540 ® is a registered trademark of Madrigal Audio Laboratories, Inc. 16 630042-1 ©1993 Madrigal Audio Laboratories, Inc. All rights reserved. Printed in U.S.A.
