MC462 Owners Club

[mati1979]

Originally Posted by Bob Bubeck

I believe that you will find that the MC462 has greater grip and tighter response in the bass and midbass (e.g., more realistic tympani rolls), a less colored midrange and upper midrange, and a larger, more open deeper sound stage than the MC302.

I wonder what the difference would be with a 312

[Stahle]

Originally Posted by mati1979

I wonder what the difference would be with a 312

I wondered the same thing at the time I purchased my MC462. Since neither were available to listen to, I thought it best to pay the extra and get the MC462 for the 50% increase in power and the quad balanced technology. After living with the MC462 for nearly six months, let’s just say that I’m no longer wondering if I should have saved the money because I love this amp.

[inlinephil]

We bought our MC462 used about 6 months ago and have loved it since the start. This particular unit was replaced by its seller with two 1.4kW monoblocks after only a few weeks of listening. It sat in its box for almost a year before he decided to sell and we are glad he did.

As a side note, while struggling students in college back in 1972, my wife was eyeing up the MC2300 and wanted to trade our Duster 340 for it. The owner agreed but at the time it was our only form of reliable transportation. Unfortunately, I had to say no and bought a MC2100 instead [still have it], but I loved her enthusiasm. Now after several decades, she finally has her dream amp and we still have our car!

Our system is mostly hand made [EET/BMET from Oklahoma State] and love to tweak things. The output stage of our preamp [Audio Research LS27] already is capacitively coupled; so is the input stage of the MC462. This is redundant and one of them can be eliminated. Since the ARC uses VERY high quality coupling caps [MC462 uses ceramic SMD 10uF/50V], one day in the near future I will short out those MC462 input caps with some pieces of PC-OCC wire and we will see how the sound changes. I anticipate good things.

While I'm in there, I will swap out the 15A fuse and socket to a low-Z 15A magnetic breaker and look at how difficult it would be to upgrade the 0.5 ohm 5W 5% emitter resistors to hand-matched non-inductive types [they're mounted on the heat-sink PC board which means a lot of disassembly for access].

There may be other improvements waiting to be performed [ground loops, etc.] but I will have to examine the circuitry and layout closely to see what else could be done. For now, it sounds *VERY* good and as others have mentioned, pianos are incredible as is the tight bass. So stay tuned and be patient...

[Formerly YB-2]

Originally Posted by inlinephil

Our system is mostly hand made [EET/BMET from Oklahoma State] and love to tweak things. The output stage of our preamp [Audio Research LS27] already is capacitively coupled; so is the input stage of the MC462. This is redundant and one of them can be eliminated. Since the ARC uses VERY high quality coupling caps [MC462 uses ceramic SMD 10uF/50V], one day in the near future I will short out those MC462 input caps with some pieces of PC-OCC wire and we will see how the sound changes. I anticipate good things.

There may be other improvements waiting to be performed [ground loops, etc.] but I will have to examine the circuitry and layout closely to see what else could be done. For now, it sounds *VERY* good and as others have mentioned, pianos are incredible as is the tight bass.

You are a most brave 'tweaker'. Good luck with what most folks would consider an already well designed piece.

I used to have great fun as a child making and sailing small sailboats on Theta Pond. But, that was ~20yr before you got to OSU.

[inlinephil]

It's not that the MC462 is not well designed; it is. However, companies must make a profit to stay in business and cost cutting is an essential part of that business model.

It is in these areas that sonic improvements can be made. I'm pretty certain that the design lab's version of the MC462 has a resemblance to the production version but it is definitely not 1:1 identical.

So if one knows where cost savings are implemented and if one changes that part of the design to a higher quality but yet more costly component, additional sonic improvements can be achieved.

For example, one of the main differences between the MC452 and the MC462 is the size of the capacitor bank in the main power supply [about 300 Joules for the MC462 vs. 200 Joules for the MC452]. This is part of what gives this the MC462 its commanding bass authority and exceptional inner detailing. To increase this energy storage capability, the increased price had to follow [you never get anything for nothing].

One cannot just start yanking out components and replacing them with something else. There's a lot of thought and engineering behind why certain devices were chosen in the production version like stability and freedom from spurious oscillations to name just two. But knowing what to look for and exactly what to use instead is the key. For example, I would never change out the bridge rectifier in this unit since footnotes in the schematic specifically warn against replacing it with another type [of which there are many]. Obviously the engineers did their homework and listened to the differences settling on that particular device.

So yes, it is a brave/bold effort to try and improve an already great product. But these two options [the fuse to CB and the capacitor elimination] are pretty safe bets, at least for my system. The capacitor change totally depends upon your preamplifier's output stage design [e.g., DC vs. AC coupling] although the CB is pretty much universal.

[Formerly YB-2]

Phil - I'm interested in how you found that the MC462 is cap-coupled. McIntosh is notoriously stingy with schematics and technical info on their newer products. Did you open it up and trace the input? Those caps are likely there for DC protection. Will be interested in your results.

[tdelahanty]

I would like to mention three things. Mac cannot control what pre-amp is used with the 462 hence the input cap. Try to identify the emitter resistors they are probably counter wound to eliminate inductance. I would not do these mods in the event of a failure which might cancel warranty or good will repairs.

[inlinephil]

Originally Posted by Formerly YB-2

Phil - I'm interested in how you found that the MC462 is cap-coupled. McIntosh is notoriously stingy with schematics and technical info on their newer products. Did you open it up and trace the input? Those caps are likely there for DC protection. Will be interested in your results.

Yes, indeed they are there for DC input protection on the MC462. That is why I mentioned that for my preamp, the ARC LS27, it has and AC-coupled output therefore making the input caps on the Mac redundant.

Being an engineer and working with McIntosh and other well-know high-end manufacturers for decades, I have access to things most folks do not. I have the service manual for the MC462 and of course one can understand why I cannot share that with folks so please do not ask. Yes, I found the input caps on this schematic.

It will be next year before I have time to implement these changes. And yes, doing this sort of modification will undoubtedly void your warranty.

[miatadan]

Originally Posted by mati1979

I wonder what the difference would be with a 312

I had the MC312 for 5 years before replacing it with the MC462 ( after replacing complete system after it was stolen from break in in 2018 )

It is not just the power output but the additional headroom for peaks and higher current )

First time my Magnepan’s had good bass without turning on JL Audio subwoofer.

Dan

[Bernhard]

Hi,

I consider to buy a McIntosh MC452 (I know this is the 462 forum here, but I guess for my question that doesn't matter - just correct me if I am wrong).

I have two questions:

I have a Rotel Michi P5 Pre-Amp (don't hate me too much..) and I could not find a good information if there is a way to use the remote power wake up cable between those two. The McIntosh seems to have an additional "light"-feature added to the conventional 12V trigger cable used by most pre-/power amps I know. So I wonder if that could/would still work?

The McIntosh MC452 has 2,4 and 8 Ohm power outputs on the back. I run very old Infinity Kappa 8.0 and they will need the 2 Ohm outputs - so far so good. But so far I had them bi-wired (I don't want to start an argument if that makes any sense - I basically had to, because I don't have the bridges for the terminals and all of my amps so far supported bi-wiring - so I simply went with that...).

The question I have now - the McIntosh MC452 has multiple output terminals, so is it possible to use more than one of them at the same time? I didn't find details about that in the manual. I was asking myself if I could connect the bass to the 2 ohm and the 2. speaker terminal to the 4 ohm for the rest of the speakers of the Kappa.. Or if only the 2 ohm terminal can be used and I do have to find a bridge for the terminals on the speaker.. I didn't find any information regarding that in the manual, so I hope you could help me with that?

regards,
Bernhard