Thermal Protection

	Soft Start Switch
	Q1
Temp	Comparator
TS1, R25	U5B
	THERMAL Indicator
	CR2

The Thermal protection is activated, and shuts down audio operation, when the amplifier heatsink reaches an excessively high temperature. The voltage divider R22 and R23 establishes the reference voltage on pin 5 of U5B. The control voltage, Temp, on pin 4 is established by the voltage divider TS1 and R25. TS1 is a NTC (Negative Temperature Coefficient) thermistor, mounted on the heatsink. As TS1 warms and the resistance falls, the voltage on pin 4 rises. When the voltage on pin 4 exceeds the voltage on pin 5, the output on pin 2 goes low, shutting down the Soft Start switch Q1 and lighting the THERMAL indicator.

Clipping Indicator

Drive	Clipping	LED Driver	CLIP Indicator
Signal	Detector	U5C	CR3
	U5A

The CLIP indicator is driven by the buffer U5C which is controlled by the comparator U5A. The voltage divider R56 and R57 established the reference voltage for the clipping detector at pin 7 of U5A. The reference voltage scales the output of U5A to indicate when the Drive Signal, at pin 6, demands in excess of the available voltage or current of the output stage. The output of U5A is stretched by R55 and C30 to prevent the CLIP indicator CR3 from flickering. Hysteresis is applied to the LED driver U5C by R53 to stabilize the output during input transitions.

Signal Present Indicator

Amplifier	Signal	LED Driver	SIGNAL
	Detector		Indicator
Output		Q8
	U5D		CR4

The SIGNAL indicator is controlled by the comparator U5D and the transistor Q8. The amplifier output is connected to the input pin 9. The voltage divider R58 and R59 scales the output voltage to change the comparator output state at an equivalent input voltage of 30mV. The output at pin 14 controls the transistor Q8 to shunt across and turn off the LED CR4.

– 15 –

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.