Okay I Bought the Magnepan 3.6's

Thanks for all the very interesting feedback, comments, and recommendations. My final analysis of the Mac 402 is that it is not the amp I want for my rig and my new 3'6's... I'll have to look elsewhere. Still leaning towards one of the Pass or possibly trying the Wyred 4 Sound ST-1000; in any case I am still looking!

If you happen to live in the Atlanta area and have one of these, please let me know.

Bombaywalla,

You are correct the Maggies are a relatively benign load in terms of current requirements; as long as the amp is comfortable into 4 ohm loads, there shouldn't be a problem. What you are forgetting is that Maggies do suffer from dynamic compression that gets worse the harder you push them. Your calculations would be correct if they were linear, but they are probably suffering from 2-6 dbs of compression in the mid 90 db range.

My experience with my 2.7s was that with 200 watts behind them, they were completely underwhelming. When I borrowed a friends older Yamaha M80 amplifier (330w/ch) I flat out would run it out of power, the VU meters would light up like a Christmas tree in Times Square. It was only when I bought an Adcom GFA-5500 (350w/ch with 1.7 db of headroom i.e. 500 a side on peaks) that they started feel better. Even with the Adcom, I would light up the clipping lights on loud passages. I ultimately ended up with a Sunfire Stereo (600 per side) and if I could swing it would go to the signature version at 1200 per side. This was all in a 14 x 17 foot room.

The x.150 puts out 300 watts/ch into a 4 ohm load, which as others have said is not adequate from their experience. My experience says that 300 watts/ch in a smaller room wasn't adequate, so I have no reason to believe it would be in a larger room.

The article you cite in Stereopile sums it pretty well when the review says "Another consideration is that although the 3.6/R is a benign load—mainly resistive and a fairly flat 4 ohms—at 86dB/2.83V/m they’re not terribly sensitive. The VAC Renaissance 70/70 is an unusually strong 70W amp, but wasn’t really enough to make the Maggies sing. The Mark Levinson No.20.6s, VTL Ichibans, and Classé CAM-350s all did better jobs of resolving low-level dynamics and detail, and opened up the soundstage noticeably. I spent time with all three, but ended up preferring and doing most of my listening with the Classé monoblocks, which are rated as delivering 700Wpc into the Maggies’ 4 ohm load."

Don't get pushed by some of the above posts into thinking you must have 350wpc, 600wpc, 1000wpc, 1,200 wpc. And the post above misstakes my experience that the Pass x150.5 was inadequate - wrong!

Of course, if you want to spend the $$, then you can't go wrong with a higher powered amp, other things being equal.
But, as I said above, it depends on how loud you play the maggies. The Pass 150.5, as I said above, is really a 250wpc amp disguised as a 150wpc, as per the Hi Fi News tests and is much more than merely adequate.

My 150.5 has more power than my prior Classe CA-201 (stated as 200wpc). My friend's 150.5 had, in his opinion, more power than his prior Classe CA-401 (400wpc), particularly in producing deeper more powerful bass than either of the Classes, which both of us felt were somewhat on the soft side on the bass. The Pass was better in all other categories also - detail, transparency, etc.

But, if you are unsure about the 150.5 and want to ensure adequate power but not go overboard on the power/price issues, I would say you can't go wrong with the Pass X250.5.

DNE, when you say the Pass is really a 250watt amp disguised as a 150 watt amp, that is a bit misleading. Most well designed high end amps will handily exceed their rated output by 1-2db's, the amount of out performance you claim for the Pass. I think the pass is a great amp, if I were rich, I would buy one, but I also think given the size of the buyer's room, and fact that he was not enthused with the McIntosh 402 with 400 watts per channel and 2 dbs of headroom, that he would be well served by having the extra 3-5 dbs that a bigger amp would put out, whether from Pass Labs, Bryston, Wyred, Sunfire, McIntosh or any other number of excellent manufactures.

For Stickman, I have to ask if you watched the meters on the Mac when you were using it. For the levels you wanted, were you getting close to clipping it? That would give everyone a better idea of your power needs.

It's simple. ARC. The new integrated amp at 200 watts into 8 ohms and almost 400 into 4 ohms will simply knock you out.
ARC and Magnepan is one of the most satisfying combinations
in hifi today, yesterday and most likely tomorrow!