Beta 3 U15a Service Manual -

Bi-amp design (typically Class AB or Class H for the LF/HF sections, depending on the production module generation). LF Power: 300W RMS into 4 Ohms. HF Power: 100W RMS into 8 Ohms. Crossover Frequency: 1.8kHz. Input Sensitivity: Line: 0dBV (0.775V); Mic: -40dBV. 2. Module Layout & Section Identification

Specifics on the 15-inch woofer and high-frequency compression driver.

Unbolt the compression driver from the integrated horn wave-guide. Handle with care; dropping the driver can crack the ferrite/neodymium magnet structure. Step 3: Removing the Amplifier Module (Rear Panel)

If you want, I can:

In these communities, be respectful and provide as much detail as possible about your issue (e.g., "My U15a powers on, and the woofer works, but the horn is silent"). This increases your chances of getting helpful replies.

| Rev | Date | Description | Author | |-----|------|-------------|--------| | 1.0 | 2024-01-15 | Initial service manual release | Technical Publications |

The service manual divides the internal electronics plate into three distinct modules. Identifying these sections prevents accidental damage to high-voltage components during probing. Power Supply Unit (PSU) Located at the base of the internal PCB assembly. Beta 3 U15a Service Manual

Working on active loudspeakers exposes technicians to lethal voltages. Follow these basic protocols:

Always discharge the main power supply capacitors using a high-power resistor (e.g., 100 Ohm, 10W) before touching the PCB trace side. Residual energy can linger for hours after power-off.

Remove the perimeter screws surrounding the metal rear plate. Do not remove the screws holding the heatsink to the plate unless you are replacing thermal paste. Tilt the plate outward slowly. Bi-amp design (typically Class AB or Class H

: 2 x XLR inputs matching balanced configurations at 20 kΩ and unbalanced at 10 kΩ.

Strange noises or vibration