Block Diagram

Technical Description

Design Philosophy

The design philosophy incorporated in the MC501 in- volved several different techniques, all based on sound sci- entific logic. Every stage of voltage or current amplifica- tion must be as linear as possible prior to the use of nega- tive feedback. McIntosh engineers know how to properly design negative feedback circuits so they contribute to the extremely low distortion performance expected from a McIntosh amplifier. The typical McIntosh owner would never accept the approximately 100 times higher distortion of many non-feedback designs.

Double Balanced Push-Pull design is used from input to output. Each half of the amplifier contains complimentary balanced circuitry. The resulting double balanced configu- ration cancels even order distortion. Refer to figure 14.

All transistors are selected to have nearly constant cur- rent gain over the entire current range they must cover. Output transistors in particular, have matched uniform cur- rent gain, high current bandwidth product and large active region safe operating area. An automatic tracking bias sys- tem completely eliminates any trace of crossover distor- tion. Precision metal film resistors and low dielectric ab- sorption film capacitors are used in all critical circuit loca- tions.

The output signals of the two balanced circuits are coupled together in the unique McIntosh MC501 Output Autoformer. It provides low distortion power transfer at frequencies from below 20Hz to well beyond 20,000Hz with optimum impedance points of two ohms, four ohms and eight ohms. The unequaled expertise of McIntosh in the design and manufacturing of autoformers is legendary in the high fidelity industry.

The high efficiency circuit design of the MC501 con- tributes to low operating temperatures. More than 1,045 square inches of heat sink area keep the MC501 operating safely with convection cooling. No fans are needed.

Autoformers

All solid state power amplifier output circuits work best into what is called an optimum load. This optimum load may vary considerably from what a loudspeaker requires. In the case of more than one loudspeaker connected in par- allel, the load to the power amplifier may drop to two ohms or even less. A power amplifier connected to a load that is lower than optimum, causes more output current to flow, which results in extra heat being generated in the power output stage. This increase in temperature will result in a reduced life expectancy for the amplifier.

of the

Amplifier and Meter Circuitry

Figure 14

MC501 specifications

The McIntosh MC501 is a high-performance monaural amplifier that exemplifies the blend of cutting-edge technology and exquisite craftsmanship inherent in McIntosh products. Renowned for its exceptional audio performance, the MC501 is designed to deliver powerful and precise sound reproduction, making it a prized component in any audiophile's collection.

One of the standout features of the MC501 is its output power, providing a robust 500 watts into 2, 4, or 8-ohm loads. This level of power ensures that the amplifier can drive even the most demanding speakers with ease, producing dynamic sound across various listening environments. The MC501 features a unique autoformers design, allowing it to maintain consistent impedance, which results in superior sound clarity and dynamics regardless of speaker type.

The technological advancements in the MC501 include McIntosh's iconic Power Guard circuit. This system monitors the audio signal and automatically reduces the amplifier's output if it detects any distortion, protecting both the amp and the connected speakers from damage. Additionally, the amplifier incorporates McIntosh's Sentry Biasing technology, which ensures optimal performance while preventing overheating, making it a reliable choice for extended listening sessions.

Aesthetically, the MC501 is as impressive as it is functional. It showcases the brand's signature blue watt meters and backlit logo, which not only enhance its visual appeal but also provide real-time feedback on power output levels. Its solid construction and elegant design make the MC501 a striking addition to any audio setup, embodying a luxurious look that is synonymous with McIntosh.

Moreover, the MC501 is engineered with a balanced design, featuring both balanced and unbalanced inputs to ensure compatibility with various audio sources. This flexibility allows users to integrate the amplifier seamlessly into their existing audio systems while maintaining the highest sound quality.

In summary, the McIntosh MC501 monaural amplifier delivers exceptional power, advanced technologies, and unrivaled sound quality. Its robust output capabilities, protective features, and stunning design make it a cornerstone of any high-end audio system, appealing to both seasoned audiophiles and newcomers looking to elevate their listening experience. With the MC501, McIntosh continues to uphold its legacy of excellence in the world of high-fidelity audio.