Hafler GX2300CE, GX2600 What Else Distinguishes These AMPLIFIERS?, Universal Line Voltage Input

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WHAT ELSE DISTINGUISHES THESE AMPLIFIERS?

Constant power into varying impedance. It takes twice as much current to develop a given wattage into 2Ω as it does into 8Ω—but only half the voltage. Many amplifiers quote a high output current at 2Ω but have an unpublished operating time measured in a handful of seconds—before thermal shutdown (hopefully) precludes thermal meltdown.

Our solution for this is selectable rail voltages for optimizing the amplifier to the load. This is impractical for conventional line-frequency supplies—and it comes at a cost for switching supplies. A full PWM design is needed, adding a coupled out- put inductor, a current-sense transformer and a current-mode controller IC. An impedance selector switch is also needed for each channel, simultaneously altering the rail voltage and the current limit. Each channel of the amplifier can be inde- pendently optimized for 2Ω, 4Ω, and 8Ω, useful in bi-amping and tri-amping, etc. Both 70 and 100 volt constant voltage line operation are possible. A chart on the back of the amplifier explain the various options.

UNIVERSAL LINE VOLTAGE INPUT

Voltage selection is provided in two bands: 100-140 volts and 200-260 volts, (both 50/60 Hz) via two quick-connect termi- nals located on the EMI filter board, accessed by removing the top cover. The current-mode control system automatically corrects for the bulk of power line variation with each band. This allows most of the PWM action to be reserved for pro- gramming and regulation of output voltages. A flyback topology provides the numerous housekeeping low voltages required by various circuits.

PROTECTION CIRCUITS

Fan control circuit - Each amplifier channel has a fan control circuit that measures the temperature of the heatsink, and adjusts the fan speed accordingly. This thermally-tracking fan speed circuit keeps fan noise to a minimum when power demands are low. Typically the fans will be turning slowly even at idle conditions - although abnormally low room temper- atures may allow the fans to turn off completely. The fan control circuit also has a turn-on blast feature that runs the fans at full speed for a few seconds every time the amplifier is turned on. This serves the dual function of cleaning out the air tun- nel, and providing a simple means to check the fans for proper operation. If you suspect that the fans are not operating cor- rectly, try turning the amplifier off, then listening or feeling for the turn-on blast when the amplifier is turned back on.

Thermal Standby - If excessive heatsink temperature is detected, the individual amplifier channel will go into thermal stand- by mode. The amplifier will be turned off, and the THERMAL LED illuminates until heatsink temperatures return to normal. At that time the amplifier automatically turns back on, and continues operating normally.

NOMAD protection - The amplifier output MOSFETs are protected from excessive power dissipation by NOMAD protec- tion circuitry. NOMAD (Non-Multiplying Advance Decision) limits the power when it measures signal voltage and current conditions that will exceed the pre-determined power limit of the MOSFETs. This instantaneous power calculation is per- formed on each output MOSFET, causing the amplifier to automatically limit power when needed. In this way, a speaker load with an impedance “dip” over a particular frequency range will only activate the NOMAD protection when sufficient audio is present at that same frequency range, but continue operating normally otherwise.

Short protection - The NOMAD protection circuit also protects against shorts, and will instantly limit the output power if speaker wires are shorted together. Normal operation will continue immediately after the short is removed.

Power Supply Current Limiting protection- The switching power supply will protect itself from excessive power dissipation by continuously monitoring currents in the switching MOSFETs. The Current Limiting circuit measures the currents in the switching MOSFETs and will instantly limit them to a safe level.

Soft turn-on/fastturn-off- Speaker loads are protected from turn-on/turn-off transients by a circuit that monitors the power supply, and controls the amplifier when power on/off events are detected. At turn-on, this circuit waits for power supply voltages to settle, then sends a turn-on ramp signal to slowly turn the amplifier on. At turn-off, this circuit acts quickly to turn off the amplifier before power supply capacitors discharge, and voltages collapse into the output signal - causing speaker “pops”.

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Contents Page Page Table of Contents Declaration of Conformity U T I O N L I G R O H T U N G T E N T I O N Notare Importanti Informazioni Sulla Sicurezza Specifications GX2300 GX2600Technical Design Features WHY a NEW Amplifier TOPOLOGY?Introduction What Else Distinguishes These AMPLIFIERS? Universal Line Voltage InputProtection Circuits Design Features Biamp StereoInstallation POWER/THERMAL RequirementsCooling NoiseAudio Ground CHASSIS/FLOAT Switch Power SwitchOutput Operation InputEarth Grounded Source Equipment Floated Source Equipment Floated equipmentDelay PhaseCD Horn Equalization CrossoverSTEREO/BIAMP Switch STEREO/MONO 70V 100V SwitchLevel Controls ProtectLoad Switch SignalThermal ClippingWiring Diagrams Stereo Mode GX2300/GX2600Bridge Mono Mode GX2300/GX2600 2300100V Mono Mode GX2300/GX2600 70V Stereo Mode GX2600 onlyService Policy and Limited Warranty What is CoveredLayouts EMI Filter Crossover CD EQTime DELAY/PHASE Inverter Schematic Diagrams Bridge RectifierPC-2460-e.sch-1 Crossover CD EQ Time DELAY/PHASE Inverter Amplifier C600maualB.sch-1 Protection C600maualB.sch-2 High Voltage Control Page Housekeeping Control C600maualB.sch-6 Input C600maualB.sch-8 Power C600maualB.sch-5 MAN-2987-A 6/00 MJT

GX2600CE, GX2300, GX2600, GX2300CE specifications

The Hafler GX series amplifiers, including the GX2300CE, GX2600, GX2300, and GX2600CE, represent a sophisticated blend of power and precision in audio amplification technology. Designed for both professional and home audio use, these amplifiers deliver high-quality sound reproduction while maintaining reliability and durability.

The GX2300CE and GX2600 are particularly noted for their robust power output. The GX2300CE can produce an impressive output of 125 watts per channel into 8 ohms, making it suitable for driving a wide range of speakers with ease. The GX2600 pushes this power even further, targeting serious audiophiles who demand more dynamics and headroom from their audio systems. With a 220 watts per channel output at 8 ohms, it is built to handle even the most demanding acoustic environments.

One of the standout features of these amplifiers is their use of Hafler's proprietary "Current Feedback" technology. This innovative design allows for greater bandwidth and reduced distortion, ensuring that the audio signal remains true to the original source. The result is a clear, transparent sound that enhances the listening experience. Alongside this technology, the amplifiers come equipped with multiple input options, including XLR and RCA inputs, providing flexibility for various audio sources.

In terms of build quality, the GX series showcases Hafler’s commitment to durability and aesthetics. The rugged chassis is designed not only to withstand the rigors of both studio and stage environments but also to minimize resonance and external vibrations. The front panel is user-friendly, with easily accessible controls for volume and input selection, enhancing convenience in any audio setup.

The GX2300 and GX2600 also feature advanced thermal protection circuitry, preventing overheating and ensuring long-term reliability. This feature is particularly beneficial for extended playback sessions or in high-demand situations when the amplifiers are pushed to their limits.

In conclusion, the Hafler GX2300CE, GX2600, GX2300, and GX2600CE amplifiers are engineered to provide exceptional audio clarity, robust power, and advanced technology. Whether used in a professional studio or a home theater system, these amplifiers stand out for their performance and adaptability, making them a favored choice among audio enthusiasts and professionals alike.
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