Bose Acoustimass 3 Series Manual 

parallel for 115V operation, depending on the position of the customer accessible voltage select switch. If the system is accidentally energized at 230V with the switch in the 115V position, the replaceable fuse (F1 located on the Main PCB assembly), will open the circuit within two minutes. This will be the only damage to the system. A non-serviceable thermal fuse is located inside the transformer to limit the maximum temperature to 145 °C under abnormal conditions. However, in most cases the externa ...

Frequency Response Curves Figure 2. Left/Right Channel Frequency Response Curve AM-3P II bass channel frequency response with bass control at min., max. and flat positions for 30 and 200 mVrms input level. A boost occurs at 55Hz for low input levels-i.e.-30mV. The gain measurements in this graph should be referenced to the input level. AM-3P II left/right channel frequency response with treble control at min., max. and flat positions. The gain measurements in this graph should be referenced to the input level. ...

High frequency equalization and crossover is achieved through three cascaded active EQ stages. These stages consist of U103, U104 and U105. The purpose of equalization is twofold: • It provides very sharp low frequency attenuation below 200 Hz (the crossover frequency) to prevent overload of the L/R speakers • It provides finely tailored correction in the speaker passband so that overall frequency response of the system is acoustically correct The U103 stage is a combination 2nd order 200 Hz high-pass filter and 5 dB 2 kHz dip notch filter. The U10 ...

Primary Voltage: 120 Vrms, 60 Hz Nominal (Test Circuit A) 240 Vrms, 50 Hz Nominal (Test Circuit B) Exiting Current @ 10% High Line: 200mA @ 132 Vrms, 60 Hz 300mA @ 264 Vrms, 50 Hz Secondary Load Line (@ Nominal Primary Voltage): Vout = 21.0 Vdc Maximum (Referenced to C.T.) @ No Load Vout = 14.0 Vdc ± 5% (Referenced to C.T.) @ Idc = 3.2 A V1 = 10.0 Vrms ± 10% (Referenced to C.T.) @ No Load ...

*S1A,*S1B Cable Assy., Quick Disc 145314 *See Note 5 *P/N until 1/13/95 *S1A,*S1B Switch,Rocker, SPST,Wired 176259 *See Note 5 *P/N as of 1/13/95 *S2 Switch,Slide,DPDT 145307 *See Note 5 *S1 Switch,Rocker, SPST 143629 *See Note 5 AM-3P II Main EQ PCB Assembly Part List Miscellaneous ! ! ! Notes: 1. Used on PCB 175302-1 US/International 2. Used on PCB 175302-3 Eur ...

NOTE: These procedures test the satellite without the bass module. 1. Sweep Test A. Connect an oscillator to a power amplifier. Adjust the amplifier output to 4 Vrms. Connect the amplifier leads to the satellite (cube speaker) input terminals. Sweep the oscillator from 100 Hz to 5 kHz. If any twiddler buzzes or sounds distorted, replace it. 2. Phase Test IMPORTANT: Supply voltage should only be momentarily applied to the satellite input terminals to avoid possible damage to the twiddlers. A. Set a DC power supply to 8 volts. To ensure that each twiddler is connecte ...

4X 21 24 22 23 Figure 7. Woofer Location in Module 6 5 4 2 3 1 7 Release Snaps ...

NOTE: This test can be performed with a fully assembled module. A. Connect an oscillator to the module’s L/R audio input terminals. Adjust the oscillator to 100 Hz, 220 mVrms. B. Rotate the bass control knob fully clockwise and counterclockwise from it's center or “normal” position. The bass level should increase and decrease cleanly without making a scratchy noise. Clean or replace any potentiometer that makes this noise. C. Repeat this procedure for the treble control using a frequency of 4 kHz. 4. Frequency Response of L/R (Twiddler) Channels NOTE: This test ca ...