Audio professionals have long recognized Ashly products for their innovative design and sturdy construction. Since 1982, the company has been producing amplifiers using power MOSFET technology. Twenty years of continual research and improvement have yielded the Powerflex 6250 multichannel amplifier ($2,069).
The 6250 is essentially three separate stereo amplifiers, each providing 250 Watts per channel of power to 4 ohms. All connections and controls, with the exception of the power switch, are on the rear panel. Each channel features separate input level controls. Grouped controls for stereo pairs include a low-cut filter, offering 12 dB per octave of attenuation below 50 Hz, a stereo/mono switch and a dual channel/bridge mode switch.
When in bridge mode, each stereo pair provides 500 Watts continuous into 8 ohms. The system is compatible with 25V and 70V systems supplying 150 Watts at 25V in stereo mode and 500 Watts at 70V in mono bridged mode.
The Powerflex 6250 employs internal microprocessor and DSP algorithms to optimize output switching characteristics. This optimization results in a “spread spectrum” switched output that varies with input amplitude and frequency. According to the company, this circuitry eliminates the usual harshness associated with high-frequency audio in standard Class D amplifiers.
Ashly also uses microprocessors to monitor and control the 6250’s self-diagnostics. Damages caused by excessive high frequency, DC offset, thermal overload, power supply over/under voltage, AC power interruption, and output overcurrents are all prevented by the system. The protection circuitry is allocated in stereo groups so a fault on one channel of a stereo pair will mute both channels of that pair. The microprocessor continues monitoring the circuit and reconnects the speakers after several seconds when the fault is cleared.
A two-speed fan cools the amplifier. The fan switches to high speed at a measured heat sink extrusion temperature of 70-75 degrees celsius. When the temperature reaches 85-90 degrees celsius the amplifier goes into protect mode.
Included on the front panel are status LEDs. Separate lights for protect, thermal, clip and signal indicate the operating condition of each of the six channels. The power switch and associated LED are also located here.
I used this amplifier for a variety of uses and in all cases it performed exceptionally well. First I ran it in a stage monitor rig. For most small jobs, 250 Watts is enough power and the fact that there are six channels of it in only three rack spaces is extraordinary.
I also ran the amp in a typical install type multiple-speaker set up. The built-in high-pass filter proved especially useful. The amp sounded full without challenging the speakers.
This is a very versatile amplifier. The high output levels, compatibility with 25V and 70V systems, and advanced protection circuitry qualify it for a multitude of applications.
Contact: Ashly Audio at 800-828-6308; 716-872-0010; www.ashly.com.