⭕ One McIntosh MC402 Two Channel High Power Solid-State power amplifier.



This amp is in extremely fine shape. It has been tested, it has the McIntosh box and packing (actually a box within a box) for safe travel, a copy of the owners manual, and a power cord.



I looked it over and I cannot find any blemishes of significance to report.



If youve been looking for an MC402 is super shape, your ship has come in!



This amplifier provides enough power to bring out the potential from any speaker. It puts out a minimum of 400 Watts Per Channel continuous RMS across the 20-20,000Hz range with that super low .005% distortion.



Some power amps have high power into 8-Ohms but can overheat into 4-Ohm speakers and even blow up into 2-Ohms!



Other high-end amps may deliver their highest power into 2-Ohms but then deliver half power into 4-Ohm speakers and very little power-for-the-money into 8-Ohm speakers. Its just a compromise. A compromise McIntosh is unwilling make.



This amplifier is different; it has OUTPUT TRANSFORMERS (Autoformers). They match the speaker load to the amplifier. That means that this amplifier can pump out 400 Watts into 2-Ohms. And 400 Watts into 4-Ohms. And 400 Watts into 8-Ohms!



Since this is a high-current model, if you connect a nominally 8-Ohm speaker to the 8-Ohm tap, and the speaker dips to 3.2-Ohms in the bass (like those famous British speakers), the MC402 will approximately double its power output.



The output transformer enables you to get all the power you paid for with any speaker, and not be robbed of power if you happen to NOT own low-impedance speakers!



You could even run a pair of 8-Ohm speakers on the 8-Ohm tap, a pair of 4-Ohm speakers on the 4-Ohm tap, and FOUR pair of speakers all in parallel around your kidney-shaped swimming pool (a 2-Ohm total load) on the 2-Ohm tap ALL AT ONCE!



Another MAJOR benefit of an output transformer is that the amplifier runs JUST AS COOL INTO LOW IMPEDANCES (are you listening Electrostatic speaker owners?).



This amp has HUGE heat-sinks, and LOOKS like it would run hot.



Nothing could be further from the truth. This amp runs quite cool. The heat-sinks are that large to keep the transistors cool. The cooler they run, the longer they last. Thats one reason why McIntosh amps last so long.



Another benefit of the output transformer is complete protection of the speaker from DC current in case of (very rare) amplifier failure. Other amplifiers incorporate an output relay that disconnects the speaker if the amp fails. These relays have contacts that can get dirty and corrode AND WILL FAIL WITH TIME!



With the Autoformer, any DC is shunted directly to ground and cannot reach your speakers and hurt them.



The downside to using output transformers? They add weight. This is not the amp for someone who moves every month.



These are WIDE-BANDWIDTH transformers with response from 10Hz-100,000Hz.



All speakers sound better with high power. I have sold Hi-Fi for over 33 years, and NOBODY has ever come back to me and said they bought TOO MUCH POWER. You may be considering this amp so you can power any speaker you may ever want to buy.



But what about your present speakers that cant handle all that power? Can they be damaged by the MC402?



No problem. . .just use a different tap!



An 8-Ohm speaker on the 8-Ohm tap receives 400 Watts. On the 4-Ohm tap, the same 8-Ohm speaker would see a little over 200 Watts. One the 2-Ohm tap, it would receive about 120 Watts. Is that cool or what???



There CAN BE one down side, traditionally, to ultra-high power amps, though.



More power means more amplifier gain and more transistors and a higher noise floor. Not this amp, though.



This is a QUAD-BALANCED amplifier. It works like balanced cables.



Inside, there are really two TOTALLY BALANCED 200-Watt amplifiers in EACH CHANNEL. One 200-Watt amp amplifies the music as it is.



The other identical 200-Watt amp amplifies the music OUT-OF-PHASE. Then the two signal meet up in the self-inverting mirror-image double-wound output transformer.



The power combines to 400 Watts, and the noise is cancelled! How low is the noise? A good amp has noise about 100dB below full output. Some are as low as 110dB below full output. Thats a lot better, since every 3dB more means you can play the amp as TWICE the power before you hear noise.



This amps noise floor is 120dB below full power. That is so far superior to other amps that its almost hard to comprehend.



This QUAD BALANCED circuit can ONLY be done when an amplifier has output Autoformers.



Being BALANCED from input to output, this amp will perform EVEN BETTER using its BALANCED inputs, if your preamp is so equipped. Used this way, the noise floor drops to 124dB below full output!



The amplifier is protected from overheating if not properly ventilated and run at full power (you would be deaf!) by THERMAL CUTOUTS.



Additionally, the amplifier is protected from short circuits in your speaker lines by SENTRY MONITOR.



Your speakers are protected from amplifier clipping by POWER GUARD.



POWER GUARD turns the volume down, and then back up, if the musical peak would otherwise overdrive the amp and send clipping distortion to your speakers.



The secret is the speed. . .it can turn on and off within 1/1000 of a second. It incorporates OPTICAL LDRs to do this. In other words, PROTECTION AT THE SPEED OF LIGHT!



Power guard does NOT trigger at any particular power level.



Instead, it only activates when the amplifier JUST starts to clip.



In the MC402, that about 460 Watts continuous into 8-Ohms. The amp can put out well over 1200 Watts per channel on peaks if your speaker dips in impedance at some frequency. Power Guard still lets it do that.



If, however, you try to get 1300 Watts out of it, it will simply hold at 1200 Watts so you dont clip.



This amplifier has HUGE solid-metal gold-plated speaker terminals. There are three sets for the three impedance taps. There are BALANCED and UNBALANCED inputs, and a POWER CONTROL in and out.



If you have a McIntosh preamp (or many others), connect a data cable from your preamp to the amp. When you turn your preamp on, the amp turns on.



The MC402 amp also has INRUSH CURRENT PROTECTION.



That means that the amp takes a moment to come up in voltage on turn-on. This makes the amp last longer and prevents circuit-breaker popping in older homes.



The MC402 has McIntoshs signature blue meters. They are driven by McIntoshs DYNAMIC PEAK LOCKING CIRCUIT.



It takes into account the ballistics of the meter, looks at the duration of the music peak, and forces the meter up for high accuracy even on super-short transients.



On the MC402, they also respond to CURRENT, so they are accurate even when your speakers fluctuate in impedance.



If there is a peak of 200 Watts on your 8-Ohm speaker, but at that frequency your speaker actually dips to 4-Ohms, the meter reads the real 400 Watts delivered. Brilliant!



This amplifier can also be put into MONOBLOCK MODE.



Most amps, when mono-blocked, BRIDGE themselves, putting the two channel in SERIES, which makes the amp dislike low impedance speakers. The MC402 is different.



When you put an MC402 in MONO mode, it parallels the channels. This allows the amp to deliver at LEAST 800 Watts into 4-Ohm, 2-Ohm, and 1-Ohm loads.



This would make it a perfect choice to run passive subwoofers, a chain of speakers around a building, or, if you already own an MC402, you can now have 800 Watts per channel with two of them AND STILL RUN LOW IMPEDANCE SPEAKERS!



Best of all, since they can run into 1-Ohm loads all day long and stay cool, they would be perfect for running high-current-demand speakers.



The MC402 has a thick 3-D glass panel, and LED fiber-optic lighting, so there are no light bulbs to ever burn out.



Best of all, this amp get you into THE CLUB. Whats that?



For the rest of your life, if you walk into a store to upgrade your speakers, a good salesman will most likely ask you first what kind of amp you have.



This is to ensure that you have sufficient power to give your speakers what they need for peak performance (are you listening all B&W speaker owners???).



If you have this amplifier, you can answer. . .I have a McIntosh MC402 Power amp with 400 Watts per channel continuous, 800 Watts per channel instantaneous peak Watts per channel, with under .005% distortion and Power Guard so the amp wont clip with up to 14dB of overdrive.



It also has output transformers, so I will get this full power with 8-Ohm, 4-Ohm, 2-Ohm speakers.



The salesman will tell you that there has never been any speaker made that you cannot derive peak performance from with your amp. The world is your oyster. Youre set for life, amp-wise. Is that a great feeling, or what???



You can cross upgrade amp to a McIntosh off your bucket list today.



If you want a combination of smoothness, detail, and effortless power from a power amp that can drive any speaker ever made to its potential, this is your amp.



This amp weighs 146 pounds in its box-within-a-box. The amp itself measures 17 ½ wide x 9 ½ high x about 20 inches deep including clearance for connectors.



This model also has LED fiber-optic lighting, so you never need to worry about replacing the front-panel light bulbs. . .there are none!