MPC Series Power Amplifiers Owner’s Manual TD-000074-00 TD-000074-00 Rev.
Table of Contents Table of Contents ................................................................................................................................................................................... 1 Warning notices ..................................................................................................................................................................................... 2 Speaker Output Shock Hazard ..................................................................
Cautions Sicherheitsvorschriften Rack Mounting Precautions Sicherheitsvorschriften für den Einbau in ein Gestell To avoid damage to the amplifier mounting ears and/or rack rails, the amplifier must be supported at all four corners when used in portable racks. Um Schäden auf den Befestigungsleisten des Verstärkers und/oder den Gestellschienen zu vermeiden, muß der Verstärker beim Einbau in ein tragbares Gestell an allen vier Ecken gestützt werden.
Description The MPC Series from JBL is a line of professional power amplifiers specifically designed for contracting applications. There are six models, each with two independent channels. Each model in the MPC Series line is available in a T version for driving either 200V, 140V, 100V, 70V, 50V, or 25V constant voltage lines and in a non-T versions for driving loudspeaker systems with impedances as low as 2 ohms. (See section on bridging for information about 200V, 140V, and 50V drive capabilities).
12 1 4 5 5 4 12 MPC600T front panel (MPC300, 300T, and 600 are similar) 3 12 2 1 2 3 2 4 2 12 MPC200T front panel (MPC200 is similar) 13 6 9 10 11 LOW IMPEDANCE CH1 DIR. OUTPUT BRIDGE MONO CH2 14 18 24 12 10 8 -dB 0 CH2 INPUT CH1 6 4 2 GROUND 14 18 STEREO 12 10 8 24 LEVEL INPUT PARALLEL BRIDGE -dB 0 CH1 LOW IMPEDANCE CH2 DIR. OUTPUT 6 4 2 8 14 CH1 AUDIO TRANSFORMER 0 70 100 ISOL.OUTPUT 70V 25V 100V CH2 AUDIO TRANSFORMER 0 70 100 ISOL.
b) DepthThe amplifiers require a rack depth of 45.7 cm (18 in) to clear the rear support ears. The rear panel is 42.9 cm (16.9 in) behind the plane of the front mounting rails, allowing some room for routing of wires. Stability, Reliability and ProtectionThe MPC Series is engineered for stability and exceptional reliability, with protection for open or short circuits and mismatched (underimpedance) loads. Protection is also built-in for ultrasonic, infrasonic (subsonic) and RF.
Outputs Covered barrier strips located on the rear panel allow safe, shockproof speaker cable connections to the amplifier outputs. See the diagrams for details on connecting speakers and/or distributed (25V, 70V, 100, 140V, and 200V) lines. Insulated connectors of the type shown are recommended. Always make sure the amplifier is turned off before you change any output connections or before lifting the safety shroud.
Driving Distributed Lines Make sure the sum of the power settings of all the speakers does not exceed the power rating of the amplifier. Be aware that the actual power draw on some loudspeakers can vary considerably from their tap labels. The tap labelings on some speakers refers to their power draw from the distributed line, while on others they refer to the power delivered from the transformer into the loudspeaker.
Loading an amp channelBe careful not to overload the channel when combining lowimpedance and distributed loads on the same amplifier channel, because either load affects the amount of power available for the other. The next two paragraphs explain how they load the amplifier output. Internal output signal flowEach T-version amplifer output connects directly to the LOW IMPEDANCE output terminals and to the primary of the audio output transformer.
2) Computing the minimum low impedance load with a known distributed line load The formula is: MinZ = 2 × [RatedLZP/(RatedLZP (Actual HZP × 2))] MinZ is the minimum load impedance that can be connected to the LOW IMPEDANCE output. RatedLZP is the maximum rated power of the amplifier into a 2Ω load. ActualHZP is the sum of all the power taps connected to the AUDIO TRANSFORMER output(s). Example: One channel of an MPC300T has 100 watts of distributed loudspeakers connected to the 70V (or 100V) output.
Using Multiple Distributed Line Voltages The MPC amplifiers allow you to connect distributed lines to any of the 100V, 70V, and 25V outputs at the same time. For example, a single channel could drive both a 70V and a 25V line; such flexibility could save you the expense of an additional amplifier. The total power of all the speakers connected to the AUDIO TRANSFORMER outputs should always be less than the power rating of the channel.
Bridged Mono Input ConnectionThe following diagrams show input and output connections for bridged mono mode. Note that the MPC200 and 200T models use a different method for bridged mono than do the MPC300, 300T, 600 & 600T. MPC200 & 200T Bridged Mono Configuration 1) To engage the bridged mono mode, jumper the barrier strip inputs on the rear, in accordance with the diagram printed under the barrier strip inputs. 2) Connect the amplifier input to channel 1 only with the jumpers as shown to channel 2.
Low Impedance Bridged Mono ApplicationsThe bridged mono mode produces higher output voltages with the trade-off of requiring a higher impedance load and providing a slightly lower damping factor. Nevertheless, it is an effective way of providing very high power levels to loudspeakers such as 4Ω or 8Ω subwoofers. Minimum ImpedanceThe bridged mono configuration places the two channels of the amplifier in series with each other. As such, each channel is seeing half the total load impedance.
Controls The channel attenuator controls, labeled in dB of attenuation, are located on the rear panel. They have 11 detents and are adjustable from 0 dB (full gain) to ∞ (full attenuation). Displays The LED displays on models MPC200 and 200T are different from those on models MPC300, 300T, 600, and 600T.
AC Power The MPC amplifiers are available for 120 or 220240 VAC, 50 or 60 Hz operation. Each amplifier is factory configured for the line voltage of the market into which it is sold. Operation Before first turning on the amplifier, turn the gain controls offi.e., fully counterclockwise until you confirm the amplifier is operating properly. MPC200 & 200T Upon turning on the AC switch, the POWER LEDs will light and the amplifier will mute for 3 seconds.
Short-Circuit ProtectionMPC amplifiers use the proven Output Averaging short circuit protection system. The circuit permits full output current even into resistive or reactive 2Ω load, but reduces the current safely by about 75% if the output is shorted. Transient MutingTurn-on and turn-off muting keeps transientsboth from the amplifier itself and from upstream equipmentfrom reaching the speakers when the amplifier is turned on or off.
Specifications Direct Output Models Audio Transformer AND Direct Outputs Electronics MPC200 MPC300 MPC600 MPC200T MPC300T MPC600T Direct Power Out 4Ω bridge 1 kHz, 1% THD 1 8Ω bridge 45 Hz20 kHz, 1% THD 2Ω load/channel 2, 1 kHz, 1% THD1 4Ω load/channel 2, 45 Hz20 kHz, 1% THD 700 W 450 W 350 W 225 W 900 W 600 W 450 W 300 W 1800 W 1200 W 900 W 600 W 700 W 450 W 350 W 225 W 900 W 600 W 450 W 300 W 1800 W 1200 W 900 W 600 W 350 W 175 W 150 W 500 W 250 W 200 W 1000 W 500 W 400 W Isolated Con
Power Consumption Some background on AC ratings is necessary to fully understand power consumption specifications. Essentially, there are three ratings of interest: (1) the legal operating current as measured by the Safety Agencies, (2) the maximum expected average current draw under worst-case program material, and (3) the peak current draw at full output power.
Heat Emission Any power that enters the amplifier through the power cord and does not exit through the speaker outputs turns into heat, which the amplifier must rid itself of by exhausting it to the outside. In indoor use this may present a challenge to the buildings air conditioning system. Use the table below to predict the heat that will be emitted by your amplifier. Note: the audio test signal for 1/8 and 1/3 power testing is pink noise; the signal for fullpower testing is a 1 kHz sine wave.
Troubleshooting PROBLEM: Channel will not come out of muting. Reduce the gain to ∞ attenuation. If this releases the muting, raise the gain back up slowly while you watch the SIGNAL and CLIP indicators. The problem may be an abnormal signal (possibly with excessive ultrasonic energy, for example) that could otherwise damage your speakers. If reducing the gain control to ∞ attenuation does not release muting, the channel is defective or overheated (see overheating section).
For Further Assistance WITHIN THE UNITED STATES: General Information or Technical Assistance For more information on JBL products, including these power amplifiers, contact your nearest JBL Professional products dealer or the JBL factory at the address below. Repairs Please do not ship your amplifier to JBL or a JBL authorized repair facility without prior authorization. You may obtain that authorization by contacting the factory or repair facility directly.
JBL Professional 8500 Balboa Boulevard, P.O. Box 2200 Northridge, California 91329 U.S.A.
