Mackie_M2600_Service_Manual电路图.pdf

M2600 FR Series Power Amplifier SERVICE MANUAL 1998, 1999 MACKIE DESIGNS, INC. 820-180-00 RadioFans.CN 收音机爱 好者资料库 Page 3 is interactive Go To Bulletins 2 SERVICE ON THIS EQUIPMENT IS TO BE PERFORMED BY EXPERIENCED REPAIR TECHNICIANS ONLY RadioFans.CN 收音机爱 好者资料库 3 INTRODUCTION This manual contains basic service information. It is essential that you have a copy of the users manual as this contains the complete operating instructions. SERVICE TECHNICAL ASSISTANCE Mackie Designs, Service Technical Assistance, is available 8AM - 5PM PST, Monday through Friday for Authorized Mackie Service Centers, at 1-800-258-6883. Feel free to call with any questions and speak with a carefully-calibrated technician. If one is not available, leave a detailed message and a qualified Mackoid will return your call asap. DISCLAIMER The information contained in this manual is proprietary to Mackie Designs, Inc. The entire manual is protected under copyright and may not be reproduced by any means without express written permission from Mackie Designs, Inc. SERVICE ON THIS EQUIPMENT IS TO BE PERFORMED BY EXPERIENCED REPAIR TECHNICIANS ONLY CONTENTS INTRODUCTION .3 Technical Support .3 Disclaimer.3 BLOCK DIAGRAM .4 SPECIFICATIONS .5 TROUBLESHOOTING TIPS. 6-7 RELIABILITY VERIFICATION . 8-9 CIRCUIT THEORY . 10-13 ASSEMBLY DRAWINGS . 14-19 PARTS LIST . 20-30 FOLD-OUT SECTIONS: schematics and pcb layouts Channel 1. 129-1 Channel 2. 130-1 Input board. 131-1 Display board. 132-1 Power Distribution and in-rush limit. 133-1 Voltage Amp and protection. 170-1 Power Supply . 171-1 Output board. 172-1 15 V supply/Fan drive board . 186-1 RadioFans.CN 收音机爱 好者资料库 Click on any item to open that page ALL BOARDS 4 + + CH.1 100 VDC + CH.1 115 VDC + CH.2 115 VDC TOROIDAL POWER TRANSFORMER LAMP FUSE MACKIE DESIGNS M2600 BLOCK DIAGRAM 9/21/1998 LOW CUT FILTER CROSSOVER INVERTER (FOR BRIDGED MONO OPERATION) FREQ CH.1 GAIN CH.2 GAIN 60-90-120Hz THRULOWHIGH LIMITOFF-LOW OUT POWER SWITCH IN-RUSH LIMIT 30 VDC +15 VDC -15 VDC 22 VAC + CH.2 100 VDC TRANSFORMER THERMAL LINE INPUT (1/4 TRS) LINE INPUT (XLR-FEMALE) THRU OUTPUT (XLR-MALE) STEREO-MONO-BRIDGED STEREO-MONO-BRIDGED STEREO-MONO-BRIDGED LIMITER CONTROL CH1 CH2 LOW HIGH LOW CUT FILTER CROSSOVER FREQ SHORT 2 IN-RUSH CONTROL THRULOWHIGH LIMITOFF-LOW OUT LIMITOFF-LOW OUT LINE INPUT (1/4 TRS) LINE INPUT (XLR-FEMALE) THRU OUTPUT (XLR-MALE) 60-90-120Hz LOW HIGH SHORT 1 (THE SHORT LEDS ARE JOINED IN BRIDGED MODE) LIMITER CHANNEL 1 POWER AMPLIFIER FUSE OUTPUT RELAY 100VDC 115VDC 22VAC FUSE +100VDC +15VDC +15VDC +115VDC METER DRIVE OL 3 6 9 20 SIG PROTECT SHORT SHORT 1 CH 1 SIGCH 1 SIG CH 2 SIG CH. 1 SPEAKER OUT CH. 2 SPEAKER OUT CH. 1 SPEAKON CH. 2 SPEAKON BRIDGED MONO SPEAKON PROTECTION CIRCUITRY MUTE DC OFFSET PROTECT SHORT OUTPUT STAGE CURRENT OUTPUT STAGE VOLTAGE TRANSIENT SOA FLT STEADY STATE SOA FLT OUTPUT DISSIPATION LOW VOLTAGE DETECT IN-RUSH CONTROL CH.1 DISSIPATION MUTE LIMITER CHANNEL 2 POWER AMPLIFIER FUSE OUTPUT RELAY 100VDC 115VDC 22VAC FUSE +100VDC +15VDC +15VDC +115VDC METER DRIVE OL 3 6 9 20 SIG PROTECT SHORT CH 2 SIG PROTECTION CIRCUITRY MUTE DC OFFSET PROTECT SHORT OUTPUT STAGE CURRENT OUTPUT STAGE VOLTAGE TRANSIENT SOA FLT STEADY STATE SOA FLT OUTPUT DISSIPATION LOW VOLTAGE DETECT IN-RUSH CONTROL CH.2 DISSIPATION MUTE +30VDC -30VDC HOT LED COLD LED CH.1 MUTE CH.2 MUTE 80 0C MUTE 52 0C UN-MUTE 80 0C MUTE 52 0C UN-MUTE CH 1 TEMP SENSOR CH 2 TEMP SENSOR OVER TEMPERATURE DETECTOR TRANSFORMER THERMAL SWITCH VARIABLE SPEED FAN CONTROLLER 45 0C 650C SPEED CONTROL CH.1 45 0C 650C SPEED CONTROL CH.2 FAN IDLE/VARIABLE CH.1 POWER DETECTOR FAN IDLE/VARIABLE CH.2 POWER DETECTOR CH.1 DISSIPATION CH.2 DISSIPATION FAN 1- 1+ 1- 1+ - + - + 1- 1+ SHORT 2 (THE CHANNELS ARE SUMMED IN MONO OR BRIDGED MODE) Block diagram 5 Maximum Power at 1% THD, midband: 500 watts per channel into 8 850watts per channel into 4 1300 watts per channel into 2 1700 watts into 8 bridged 2600 watts into 4 bridged Continuous Sine Wave Average Output Power, both channels driven: 425 watts per channel into 8 from 20Hz to 20kHz, with no more than 0.025% THD 700 watts per channel into 4 from 20Hz to 20kHz, with no more than 0.05% THD 1000 watts per channel into 2 from 20Hz to 20kHz, with no more than 0.1% THD Bridged mono operation: 1,400 watts into 8 from 20Hz to 20kHz, with no more than 0.05% THD 2000 watts into 4 from 20Hz to 20kHz, with no more than 0.1% THD Note: Power ratings are specified at 120VAC line voltages. The M2600 power amplifier draws large amounts of current from the AC line with continuous sine wave test- ing. Accurate measurement of power requires a steady and stable AC supply. This means the line impedance must be very low to insure that the peak AC line voltage does not sag to less than 97% of its value. If driving highly reactive loads, we recommend that the limiter circuit be engaged. Power Bandwidth: 20Hz to 70kHz (+0, -3 dB) 700W into 4 Frequency Response: 20Hz to 40kHz (+0, -1 dB) 10Hz to 70kHz (+0, -3 dB) Distortion: SMPTE IMD, TIM< 0.025% 8 < 0.050% 4 107 dB below rated power into 4 Channel Separation: 80 dB 1kHz Damping Factor: 350 400Hz Input Impedance: 24k balanced Input Sensitivity: 1.23 volts (+4 dBu) for rated power into 4 ohms Gain: 32.7 dB (43V/V) Maximum Input Level: 9.75 volts (+22 dBu) Rise Time: 60V/s Current Slew Rate 30A/s at 2 CMRR: 40 dB, 20Hz to 20kHz Load Angle: 8(jx) time independent at 8 4(jx) time dependent, T 6 min. at 4 2(1jx) time dependent, T 2 min. at 2 Transient Recovery: < 1s for 20 dB overdrive 1kHz High Frequency Overload and Latching: No latch up at any frequency or level. High Frequency Stability: Unconditionally stable, driving any reactive or capacitive load. Turn On Delay: 3-5 seconds Variable Low-Cut Filter: 10Hz (Off) to 170Hz, 2nd-Order Bessel Internal Crossover: Switched: 60Hz/90Hz/120Hz, 4th-Order Linkwitz-Riley Lowpass outputs switchable to internal Subwoofer mode. Lowpass and Highpass outputs switchable to Thru output jacks. Limiter Section: Complementary Positive and Negative Peak Detecting Indicators: 6 meter LEDs per channel SIG (Signal Present), -20, -9, -6, -3, OL (Overload) CH 1 1) Prevent output transistors saturating, 2) Drive the LIMITER LDR. Referring to the again to the 170 schematic: Q20 is a common base amplifier, it will turn on if Q2s collector rises more than three diode drops above the +100V supply, preventing Q2s collector from rising further. There are three diode drops between Q2s collector and the base of pre-driver transistor (Q26 on 129 board). Once the output from the collector of Q2 makes it to the emitter of the output devices, there will be a total of six diode drops in series. Three “drops” up and six down: As a result, the output transistor emitters will never see a voltage greater than three diode drop below the +100V supply (even if the +100V supply fluctuates) and will never saturate. This will consequently remove saturation of the output stage, as a source common mode conduction. When the amplifier clips, Q20 and Q15 also send out “clipping pulses” at their collectors that is coincident with baker clamp conduction. These clipping pulses are cross- coupled to Q21 and Q22 and are stored in C47 and C51. These stored pulses allow for quick attack and slow release required by a peak limiter. Output from Q21 and Q22 is coupled to the LDR LED section via R110 and R152. PROTECTION CIRCUITS The M2600 has several protection circuits in addition to main rail fuses on each channel. Circuits mute the amp if the output devices are loaded beyond their safe operating area (SOA). If there is DC on the output line, output relays open, disconnecting the load. The amplifier will also mute if the power transformer or main heatsink get too hot, if the input AC line voltage is low, or if either of the +/-15V supplies fails. Turn-On Inrush Current Limiter For the first second of operation there are two 15W power resistors (located on the 133 board) in series with the power transformer which eliminates what would otherwise be an extremely high turn-on current. After 1 second these resistors are shunted with a relay. This relay is turned on when the collector of Q26 (170 board) goes high. Note that either or both Q26s on the two 170 boards can turn on this relay. 12 SOA protection There are two SOA detectors in the M-2600: One that monitors steady state output stage dissipation and one that monitors transient high current events. Both detectors need to monitor the output stage current. A voltage, representing output stage current, is derived by first sampling the voltage drop across the output transistor emitter resistors. These voltages are rectified via U9A R87, R88, R59 and R89. The rectified voltage is converted to a current via U9B, Q23, and associated. This current is referenced to the output line and must first be re-referenced to the +115V supply via Q14, D47 and associated. The current available at the connector of Q14 is converted to a voltage that is ground referenced via R138 and R162. This is buffered via U8A and adjusted via R162 such that 1 amp of output stage current is equal to 100mV of detected output. This current is compared to what represents a safe operating current at U4A (part of the transient SOA-Fault detector). If the current is greater than allowed for more than 10mS (Timing determined by R77 and C36), U4B sends out a fault indication which mutes the amplifier via U3C and associated, and fires the short led for 5.5 seconds (U3B and associated). While the output stage is quite tolerant of very high current demands for a very short time, it would destroy itself if it had to provide these currents on a long-term basis. The second detector actually looks at long-term dissipation in the output stage, and if excessive, will mute the amplifier. We already have a signal that is proportional to output stage current as described above. This signal is fed to one input of analog multiplier U7 via R80 and R84. U6A and U6B and their associated components look at the -100V supply and the amplifier output line. These voltages are converted to currents via R101, R129 and R130 and are rectified and summed such that for every volt between the output line and the supply rail, 100mV is presented as output. This second signal is presented to the other input of multiplier U7 via R133 and R82. Output from U7 is in the form of a current and is converted to a voltage via R136 and U8B. The gain of this multiplier is such that for 200 watts of output stage dissipation, 1 volt of output is obtained. The output of U8B is instantaneous power and is long-term averaged via R135 and C40. The cutoff of the filter is quite low in frequency, such that even a 20Hz signal on the amplifier output results in very little ripple voltage at C40. If the voltage on C40 is greater than 5V (equivalent to 1000W of output stage dissipation), U4C will toggle, muting the amplifier and firing the SHORT LED as above. Approximately 200mS of dissipation above 1000W is required to cause a fault. DC Fault Detection The amplifier output drives the subsonic lowpass filter of the DC fault detector (R154, C65 and C64). If the amplifier were to fail and short to the +100V rail, C64/C65 will charge to more that 5V in a few hundred milliseconds. Local +/-5.1V references on U2C and U2D set the threshold where: when the amplifier output voltage is “stuck” to greater than +/-5.1V, either comparator output will go low. This will open Q27, and in turn open the speaker relay on the respective channel board. When the amplifier is initialized, “MUTE-VA” is high and this biases C64/C65 above 5.1V via D14 and R36. This offset results in a delay of about 2 seconds from when the amplifier turns on (“MUTE-VA” low) and when the speaker relay closes. Low Voltage Detector D15, D2, and R7 supply a local 5V reference and are supplied current from the unregulated +30V supply via R32. 22VAC from the +/-30V windings is half-wave rectified via D26 and stored by C18. R53 limits the absolute peak current to protect D26. The voltage on C18 is divided down 13 via R33 and R8 and compared against the 5V reference at U3A. If the AC line voltage falls to around 60% of nominal (around 70VAC), the output of U3A goes low, resetting the mute and short monostables via D5 and D12. If the +15V supply fails, D3 and D4 bias the U3A inputs such that the amplifier is also muted. In the event of the -15V supply failing, R7 is no longer able to pull the anode of D15 low, and this also causes U3A to go low and mute the amplifier. THERMAL MANAGEMENT The T-Design Heatsink/Fan cools the output devices evenly and does not collect dust on the circuitry. The fan operates at variable speeds, controlled by output stage dissipation and temperature data supplied from both LM35DZs mounted on the heatsink. Fan Control Circuit Referring to the 186 board: The fan voltage comes from a feedback regulator circuit formed by U3B, Q2, Q1 and associated components. The fan supply is actually referenced to the -30V supply, so U3A and Q3 act to shift the ground-referenced control voltage “FAST-FAN” to a -30V supply reference. The output voltage of this regulator is adjusted via R1. D7 and C9 give the fan an initial full fan voltage “kick” (28V) to insure the fan starts spinning. The “FAST-FAN” control line varies from -1.6V (Slow) to -15V (Fast). Short J3 temporarily and adjust R1 for a voltage across the fan equal to 28V. Referring to the 170 board: The fan is never allowed to go faster than idle speed (Slow) unless the output stage dissipation is greater than 136 watts and the heatsink tempe