Bridged Mono Operation, Design Theory | Ashly FTX-1501, FTX-2001

Operating Manual - FTX-1001, FTX-1501, FTX-2001, CFT-1800 Power Amplifier

9.3Bridged Mono Operation

(Normal/bridging switch in, channel 1 input used, channel 1 level control used, BRIDGED output used)

10.DESIGN THEORY

Ashly FTX Series III amplifier circuits are totally discrete using high-voltage, wide bandwidth electronics. The input section is a complimentary Darlington differen- tial amplifier stage for high common-mode rejection, low noise and low distortion. All voltage gain stages in the amplifier operate class A for low distortion. The compli- mentary MOSFET output stage has almost infinite cur- rent gain, therefore the output driver stages are nearly lossless. All circuitry within the feedback loop is discrete which allows the amplifier to recover instantly and cleanly without any spikes or glitches from a clipped condition. This overall design approach inherently assures low noise, low distortion, and excellent transient and overload re- sponse. Inputs are bridging and active balanced, and all input connections can operate as balanced or unbalanced. The MOSFET output devices themselves do not require short circuit protection and V.I. limiting circuitry; how- ever, output relays are employed for turn-on delay and speaker protection from fault conditions. The output re- lays will open if DC voltage, ultrasonic signals, a shorted output, or an internal amplifier failure is detected. Any of these fault conditions will illuminate the protect mode LEDs on the front panel. Each amplifier channel operates completely independent of the other so that one channel in protect mode will not affect the other channel. Designed

into the FTX Series III and CFT amplifiers is the hard- ware necessary for computer control and monitoring as such systems become available. All electronic components are mounted to rugged plated-through glass-epoxy circuit boards. Large computer-grade electrolytic capacitors as- sure long service.

The FTX Series III amplifiers are packaged in a rugged 16-gauge steel chasses. The power transformer is located at the front center of the chassis to minimize front panel torsion. Each channel’s electronics and heat sink are identical yet completely independent and modular, each with a single plug-in connector for ease of servic- ing. Large custom black-anodized extruded aluminum heat sinks with fan cooling provide plenty of thermal head- room.

The CFT-1800 utilizes quiet convection cooling for studio control rooms, home hi-fi, and other applica- tions where low ambient noise is essential. Like the FTX Series III, the CFT-1800 is a modular design for ease of servicing. Because of the passive cooling in the CFT- 1800, thermal headroom is somewhat reduced from that of forced air cooling, thus making it inadvisable to drive 4 ohm loads at continuous high power with this ampli- fier. It is also important to allow for free air circulation above and below the amplifier to achieve optimum cool- ing action.

FTX-1001, CFT-1800, FTX-2001, FTX-1501 specifications

The Ashly FTX-1501 is a high-performance, flexible amplifier designed for professional audio applications. Renowned for its efficient power management and robust construction, the FTX-1501 is an excellent choice for both live sound reinforcement and installed sound systems.

One of the key features of the FTX-1501 is its power output. The amplifier delivers a powerful 1500 watts per channel at 4 ohms, making it capable of driving large speaker systems without compromising sound quality. This substantial power output is essential for demanding environments, where clarity and volume are critical.

In terms of technologies, the FTX-1501 incorporates advanced Class D amplification technology. This not only provides remarkable efficiency, reducing heat generation and power consumption, but also ensures a lightweight design. The amplifier's compact form factor makes it easy to transport and install, which is particularly advantageous for mobile sound engineers and touring musicians.

The FTX-1501 also features intelligent thermal management, which protects the amplifier from overheating during extended use. Integrated cooling fans adjust their speed in response to the internal temperature, ensuring optimal performance without excessive noise. This feature is critical in ensuring that the amplifier maintains its performance under various loading conditions.

Connectivity options on the FTX-1501 are versatile, catering to various audio input needs. It includes XLR and TRS inputs, alongside binding post and Speakon outputs, providing flexibility for different setups. This connectivity facilitates easy integration into existing audio systems, further enhancing its usability.

Another important aspect of the FTX-1501 is its robust build quality. The amplifier is housed in a rugged steel chassis, designed to withstand the demands of both touring and fixed installations. The front panel features a user-friendly interface with LED indicators for power and signal status, making monitoring straightforward during live events.

Finally, the Ashly FTX-1501 embodies a commitment to audio fidelity. Its design minimizes distortion and enhances signal integrity, allowing users to enjoy clear, dynamic sound reproduction even at high volume levels. Whether for small venues or large events, the Ashly FTX-1501 amplifier is engineered to deliver exceptional performance, reliability, and versatility, making it a trusted choice for audio professionals worldwide.