Fan Speed Regulation

 

Driver

 

U9A

Temp

Fan Drive

TS1, R25

Amp

 

Q20, Q19

 

Trip Switch

 

U9B

Cooling air for each channel is provided by a DC fan. The fan is configured to track the heatsink temperature, and increases in speed as the amplifier runs hotter. The heatsink temperature, Temp, is determined by the voltage divider TS1 and R25. When the amplifier is turned on the fan will stay off until the Temp voltage exceeds the reference voltage on pin 6 of the Trip Switch U9B and drives the output high to turn on the Fan Drive Amplifier, Q20 and Q19. The Driver U9A is configured as a linear amplifier and controls the output of the Fan Drive Amp to vary the fan speed.

Output Short Protection

 

Clip Detector

 

Shut Down

 

U3A

Comparator

Drive

Switch

 

 

U3B

Q5, Q4

Signal

 

 

 

 

 

Clip Detector

 

 

 

U4A

 

Short Latch

 

 

 

 

 

 

U4C, CR14

 

 

Comparator

Short

 

 

Indicator

 

 

U4A

 

 

CR1

 

 

 

Output

 

 

 

Signal

 

 

 

The Short detector monitors the Drive Signal and Output Signal levels and shuts down that channel when a shorted output condition is detected. Recovering from the Short protection requires turning the amplifier off to reset it.

The Clip Detectors U3A and U4B monitor the Drive Signal and change state when the drive signal level is sufficient to clip the output stage. The output of U3A goes high when the drive signal exceeds the clip threshold, and is connected to the input of U3B. If the output signal voltage is not sufficiently positive during a clip event the output of U3B goes low. The output of U4B goes low when the drive signal exceeds the clip threshold, and is connected to the input of U4A. If the output signal voltage is not sufficiently negative during a clip event the output of U4A goes low.

This condition, indicating high drive voltage and low output voltage, can occur only when the output is grounded. If the output of comparator stage U3B or U4A is low for the time sufficient for C26 to charge, then U4C latches low activating the Shut Down Switch Q5 and Q4, and lighting the indicator CR1. The output of U4C is held low by CR14 and will reset only after the power is turned off.

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Hafler P7000 manual Fan Speed Regulation

P7000 specifications

The Hafler P7000 is a professional power amplifier renowned for its robust performance and reliability in live sound and studio applications. A cornerstone of the Hafler brand, the P7000 embodies advanced technology and engineering, making it a popular choice among audio professionals.

One of the standout features of the P7000 is its high power output. It delivers up to 700 watts per channel at 4 ohms, providing ample headroom for demanding audio environments. This powerful output makes it suitable for driving large loudspeakers or multiple speaker systems, ensuring clear and dynamic sound reproduction even at high volumes.

The P7000 utilizes a class AB amplifier design, combining the benefits of class A and class B architecture. This design choice ensures low distortion levels while maintaining efficient operation. As a result, users can expect a warm and natural sound with low signal degradation, making the amplifier ideal for critical listening environments.

In terms of build quality, the Hafler P7000 is constructed with durability in mind. The chassis is made from robust materials that can withstand the rigors of frequent transport and use in various settings, from professional studios to live concert venues. Additionally, the amplifier features a well-ventilated design, minimizing overheating and ensuring reliability during extended operation.

The P7000 also includes advanced protection circuitry to safeguard against overload and short circuits. This feature not only protects the amplifier itself but also the connected speakers, providing peace of mind during high-energy performances. Furthermore, the amplifier incorporates a soft start circuit, which gradually ramps up power to the speakers, preventing sudden jolts that could cause speaker damage.

Connectivity is another key aspect of the Hafler P7000. It offers a variety of input options, including XLR and 1/4" TRS connectors, making it compatible with numerous audio sources and easy to integrate into any existing setup. Balanced inputs help reduce noise and interference, ensuring clean signal transfer over long cable runs.

With its combination of powerful output, reliable performance, and versatile connectivity, the Hafler P7000 stands out as a professional-grade amplifier. Whether used in a studio setting or live sound application, it provides audio professionals with the tools they need to achieve exceptional sound quality and consistency.