JBL MPC manuale d’uso

21 MPC Series Power Amplifiers Owner ’ s Manual TD-000074-00 TD-000074-00 R e v . C[...]

1 T able of Contents T able of Contents .............................................................................................................. ..................................................................... 1 W ar ning notices .............................................................................................................[...]

2 Rack Mounting Precautions T o a void dama ge to the amplifier mounting ears and/or rack rails , the amplifier must be supported at all four corners when used in portable racks . Consult JBL Ser vice Dept for av ailability of R ear Support Brac ke ts . Lifting Precautions In order to saf ely mov e or install the amplifier, it is recommended that t[...]

3 Description T he MPC Series from JBL is a line of professional pow er amplifiers specifically designed for contracting applica tions . There are six models , eac h with two independent channels . Eac h model in the MPC Series line is availa b le in a T v ersion for dri ving either 200V , 140V , 100V , 70V , 50V , or 25V constant v oltage[...]

4 1 22 5 12 12 33 4 4 5 12 2 4 12 12 CH1 CH2 CH1 CH2 BRIDGE MONO BRIDGE MONO LOW IMPEDANCE LOW IMPEDANCE DIR. OUTPUT DIR. OUTPUT ISOL.OUTPUT ISOL.OUTPUT AUDIO TRANSFORMER AUDIO TRANSFORMER 70V 70V 25V 25V 100V 100V 07 0 1 0 0 07 0 1 0 0 0 0 -dB -dB 10 10 88 66 44 22 24 24 18 18 14 14 STEREO 12 12 CH2 INPUT CH1 C H2 C H 1 PARALLEL BRIDGE LEVEL LEVEL[...]

5 b) Dept hThe amplifiers require a r ac k depth of 45.7 cm (18 in) to clear the rear support ears . T he r ear panel is 42.9 cm (16.9 in) behind the plane of the fr ont mounting rails , allo wing some room for r outing of wires . Stability , Reliability and Protection The MPC Series is engineered for stability and exceptional reliability , w[...]

6 Outputs Cover ed barrier strips located on the r ear panel allow safe , shockproof speaker ca b le connec- tions to the amplifier outputs . See the dia grams for details on connecting speaker s and/or distributed (25V , 70V , 100, 140V , and 200V) lines . Insulated connector s of the type sho wn are recommended. Alw a ys make sure the amplifier i[...]

7 Driving Distributed Lines Make sure the sum of the pow er settings of all the speaker s does not exceed the po wer rating of the amplifier . Be aware tha t the actual power dra w on some loudspeakers can v ary considerably from their tap labels . The tap labelings on some speaker s refers to their power dr a w from the distributed line, w hile on[...]

8 Loading an amp channel Be careful not to o v er load the c hannel when combining low- impedance and distributed loads on the same amplifier c hannel, because either load af fects the amount of p ow er a vaila ble for the other . T he next two par ag raphs explain how the y load the amplifier output. Inter nal output signal f l o w Each T - [...]

9 The tables below ar e general guidelines on which combinations ar e acce ptable. MPC200T Sum of Speaker T aps Connected to AUDIO TRANSFORMER Outputs 0 W 22 W* 44 W** 88 W*** 175 W**** Load connected to 2 Ω ✔ ✗✗✗✗ LOW IMPE D ANCE 4 Ω ✔✔✔✗ ✗ output 8 Ω ✔✔✔✔✗ 16 Ω ✔✔✔✔✗ 32 Ω ✔✔✔✔✗ MPC300T S[...]

10 Using Multiple Distributed Line V oltages The MPC amplifiers allo w you to connect distributed lines to an y of the 100V , 70V , and 25V outputs at the same time. F or example, a single c hannel could driv e both a 70V and a 25V line; such flexibility could sa ve y ou the e xpense of an additional amplifier . The total pow er of all the speakers[...]

11 Bridged Mono Input Connection The follo wing dia grams 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) T o engag e the bridged mono mode, jumper the barrier strip in[...]

12 Low Impedance Bridged Mono Applications T he bridged mono mode produces higher output v oltages with the trade-off of requiring a higher impedance load and providing a slightly lo wer damping factor . Never - theless , it is an eff ectiv e way of pr oviding v er y high power le vels to loudspeak er s such as 4 Ω or 8 Ω subw oofers. Minimu[...]

13 Controls T he c hannel atten uator controls , labeled in dB of atten uation, are located on the r ear panel. T hey ha ve 11 detents and are adjustable from 0 dB (full gain) to ∞ (full attenuation). Displays T he LED displa ys on models MPC200 and 200T are dif f erent from those on models MPC300, 300T , 600, and 600T . Models MPC300, MPC300T , [...]

14 AC Power The MPC amplifiers are av ailable for 120 or 220240 V A C, 50 or 60 Hz operation. Eac h amplifier is factory configured for the line volta g e of the market into whic h it is sold. Operation Before fir st turning on the amplifier, tur n the gain controls of fi.e ., fully counterc lockwise until you confirm the amplifier is oper[...]

15 Shor t-Circuit Pr otection MPC amplifier s use the prov en Output A veraging short circuit protection system. The circuit per mits full output cur rent even into r esistiv e or r eactiv e 2 Ω load, but reduces the current saf ely by about 75% if the output is shor ted. T ransient Muting T ur n-on and turn-off m uting k eeps transients[...]

16 Specifications Direct Output Models Audio Transfo rmer AND Direct Outputs Electronics MPC200 MPC300 MPC600 MPC200T MPC300T MPC600T Direct P ow er Out 4 Ω bridge 1 kHz, 1% THD 1 700 W 900 W 1800 W 700 W 900 W 1800 W 8 Ω bridge 45 Hz20 kHz, 1% THD 450 W 600 W 1200 W 450 W 600 W 1200 W 2 Ω load/channel 2 , 1 kHz, 1% THD 1 350 W 450 W 900 W[...]

17 Power Consumption Some background on A C ratings is necessar y to fully understand po wer consumption specifications . Essentiall y , ther e are thr ee ratings of interest: (1) the legal operating current as measured by the Saf ety Ag encies , (2) the maxim um e xpected a verage current dra w under worst-case pr og ram material, and (3) the peak[...]

18 Heat Emission Any pow er that enters the amplifier thr ough the power cor d and does not exit through the speaker outputs turns into heat, which the amplifier m ust rid itself of by exhausting it to the outside . In indoor use this may pr esent a challenge to the building s air conditioning system. Use the table below to predict the hea t tha[...]

19 T roubleshooting PROBLEM: Channel will not come out of muting .  Reduce the gain to ∞ a tten uation. If this releases the muting , raise the gain bac k up slowly while you watc h the SIGN AL and CLIP indicators . The problem may be an abnormal signal (possibly with ex cessi ve ultrasonic ener g y , for example) that could otherwise dama g e[...]

20 For Further Assistance WITHIN THE UNITED ST ATES: General Infor mation or T echnical Assistance F or more inf or mation on JBL products , inc luding these power amplifier s , 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 [...]

22 JBL Professional 8500 Balboa Boulevard, P .O. Box 2200 Northridge, California 91329 U.S.A. A Harman International Company MPC MANUAL 6/98[...]