McIntosh Amp Ratings

An interesting observation I had made about mcintosh specs which I believe a one of the contributing factors to making them more universal and tube sounding is partially the autoformer deal, but also they have very low damping factor in comparison to esoteric Solid state amps… Most of them are like 100 to 150… Big amps with tons of juice that everybody seems to get off on have 600 or 2000 damping factor, to me these amps are mostly toughted as " More defined bass" or "Tighter" but to me they sound more constipated, and many times less organic than most Mcintosh designs.

Also being the damping factor is so low on them it seems that’s really the one Spec that matches up to most tube designs, which might be part of the key they seem to be more of that musical and accepted sound. I don't really know, but just an observation.

I understand McInotsh amps have a certain following, but Undertow, what you're saying makes little or no sense. Other amps sound constipated? Wow. That totally contradicts my observation, which is McIntosh amps sound fine with an easy load speakers. When you pair their amps with a difficult to drive speakers that have some impedance curves, or what have you, smaller McIntosh amps sound constipated. Actually any Mac amp up to MC501 monoblocks can not really be paired with any challenging load. You need to at least start with MC501 monoblocks for such task. And the fact that McIntosh amps don't double down doesn't help either. For example, with B&W 803D or even N803, MC402 sounds OK on lower levels, but the louder you get, the more obvious the dynamic restrictions seem.

I mean I do understand if you like McIntosh sound. That is totally up to you. But deeming McIntosh amps as above anything else is a bit of an overstatement, to say the least.

Hi, Mc-602 owner,
Yes Auto formers will restrict the dynamics as you reach the end of the power band. It's a trade off between clipping and max power.

McIntosh amps don't clip. Protecting one's speakers from damage!

So the real question is how much power does I need to achieve the volume level desired.

Fundamental rule is to double volume it takes 10 times the power.

Meaning if you like to listen to soft levels 10 watts is average, double volume is 100 watts, to double again 1,000 watts. As you can see it does not take that much volume to max out a 1,000 watt amp. How much air do you want to move? This is where the term headroom comes into being. I say you should have at least one level double volume of headroom.
My McIntosh MC-602 will put out 600 watts and not even get hot. At 60 watts I move a lot of air and still have 540 watts to play with.

Another factor one should consider when choosing a amp. HEAT will destroy it over time. McIntosh amps have a long history of running cool. Just look at all of the used 40-50 year old amps for sale on Audiogon still getting good money. With McIntosh if you keep it long enough you can sell it for more than the original price.... How many other Mfg. can claim this ?????

The last point I will make is Big amps have so much more detail @ one half watt output. I love my MC-602

My 501's drive a very difficult load in Thiel 3.6, low impendance factor but fairly stable curve, with no problem in a room probably too large for the speakers. They never run out of gas, fill the room with music and I usually crank them!

Seems to me that there's a fair amount of mis-information being batted around, here. The use of autoformers on the output end of an amp is used to ensure that there is the best transfer of power from the amp to the speakers when the speaker load is attached to the most appropriate tap for that speaker's impedance curve.

This is the same electronic principle as found in matching a Moving Coil cart via a Step Up transformer into a phono preamp, and is the basis for any matching of 2 devices where low level signals need to passed with minimum loss of energy.

If you compare the output specs into 2,4, or 8 ohms for the solid state Mac amps that do and do not have output autoformers, you'll see that the specs for the ones with autoformers will quote the same power output at all impedances. The amps without autoformers will show rising power output power as the impedance goes down. The thing here is that the non-autoformer will tend to get hotter driving lower impedance loads since there is a larger impedance mismatch. Think of that heat as power that didn't get to your speakers from that mismatch.

BTW, Mac amps are not _normally_ driven into clipping due to the Power Guard circuit, which limits output drive as maximum power is approached. You can stil abuse the amp if you really want to but I can tell you from direct experience that this feature has saved many a set of speakers in professional situations - not to mention drunken college parties.

Cheers,

David