Technical Description, con’t

With Power Guard

Figure 20

Without Power Guard

Figure 19

able, since it can damage valuable loudspeaker sys- tem tweeters. You will never experience the harsh and damaging dis- tortion due to clipping.

The Power Guard cir- cuit is a waveform com- parator, monitoring both the input and output waveforms. Under nor- mal operating conditions, there are no differences between the shape of

these waveforms. If an amplifier channel is overdriven, there will be a difference between the two signal wave- forms. When the difference exceeds 0.3% (equivalent to 0.3% harmonic distor-

tion), the Power Guard activates the PG light and a dynamic electronic at- tenuator at the amplifier input reduces the input volume just enough to prevent any further in- crease in distortion. The Power Guard circuit acts so fast that there are ab- solutely no audible side effects and the sonic pu- rity of the music repro- duction is perfectly pre-

served. The MC501 Power Amplifier with Power Guard is not limited to just the rated power output, but will actually

produce distortion free output well above its rated power due to the McIntosh philosophy of conservative design.

Power Supply Circuits

To compliment the fully balanced design of the MC501 in- corporates a high voltage power supply. Refer to figure 21. High power amplifiers draw high current from the AC power line. Therefore, it is important that they plug directly into the wall outlet.

Also, most owners desire that there be one power switch for the whole audio system. The MC501 is equipped with a circuit that provides remote Power Control from the McIntosh Preamplifier or Control Center. When the Pream- plifier or Control Center is switched On, a digital “1”

(+5V) signal operates the power relay in the MC501. The MC501 also has a remote Power Control Out Jack. The Power Control signal from this jack is delayed by a fraction of a second so that the turn on power surge of the next power amplifier occurs at a later time. This helps prevent power circuit overload that could trip circuit breakers or blow fuses, a very important feature in a high power Home Theater System employing many MC501 Power Amplifi- ers.

The MC501 can provide greater than 100 amperes peak output current to drive uneven speaker loads. Some poor speaker designs have input impedance that dip to 1 or 2 ohms at various frequencies and the MC501 has the output current reserve to drive them. It can deliver over 500 Watts Output on tone bursts. The MC501 has huge main filter ca- pacitors that guarantee an excellent signal to noise ratio and the energy storage necessary for the wide dynamic range that “Digital Audio” demands.

Block Diagram

of the

Power Supply

Figure 21

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.