Gallien-Krueger Microbass MB150S, Service Manual

Page 1: ...Service Manual Micro Bass Series...

Page 2: ...Table of Contents Operating Instructions 3 Turn On Calibration Procedures 8 Schematics 17 Engineering Change Orders ECOs 33 Bill of Materials 43...

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Page 8: ...no crossover distortion and be about 1 2Vp p 4 Flip scope switch to look at Load B up and see it is also 1 2Vp p w no crossover distortion 5 For Combo units Switch internal speaker on make sure discon...

Page 9: ...A Treble to 10 Fig 2 Treble to 0 Fig 3 B Hi mid to 10 Fig 4 Hi mid to 0 Fig 5 C Lo mid to 10 Fig 6 Lo mid to 0 Fig 7 D Bass to 10 Fig 8 Bass to 0 Fig 9 VOICING FILTERS TEST 1 Engage low cut switch co...

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Page 12: ...so that LED s are off Only the power LED should be lit 3 Look at output should be clean sine wave w no crossover distortion and be about 0 6Vp p 4 For Combo units switch on internal speaker and make...

Page 13: ...crease boost to 10 compare to Fig 15 Turn to 0 2 Change scope trigger to A and scope A to 0 1V cm range 3 Look at direct out J4 pins 2 3 compare to Fig 16 4 Engage chorus switch with rate and depth to...

Page 14: ...plug in rest of way Output should be same as above NOISE TEST 1 Remove oscillator input 2 Turn large knobs to 10 small knobs to 0 switches out 3 Connect speaker to output listen for noise It should be...

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