I'm not familiar with many amps in that category, but I have a rebuilt Counterpoint NP100 and the designer (Mike Elliott at AltaVistaAudio.com) makes the claim that his amps can drive a 2 ohm load all day long without wimping out. My amp is 100wpc and his other is 220wpc. He does have some new amps at www.ariaaudio.com that are 100wpc and 350wpc (I think...the 350wpc models may be monoblocks). I'm sure there are many others, but that's the only one that I'm aware of (my speakers' sensitivity is 89dB at 8ohm, so it's not something I think about often).
I don't know what your price range may be, but what is easily the best sounding amp for the job that I have ever heard is the Clayton Audio S40. This stereo power amplifier is a pure Class A design and will play loads down to 1 Ohm. It's rated at 50 wpc RMS into 8 Ohms, and doubles the watts each time you cut the Ohms in half (i.e. 200 wpc RMS into 2 Ohms).
If you don't think that the S40 is enough power for you, you could step up to the M100 monoblocks. These put out double the power of the S40, so you would get 400 wpc into a 2-Ohm impedance load.
They are built like a tank, with huge heat sinks covering the entire top of the amplifier, and they seem to run flawlessly forever.
I've used the S40 in my system for over 3 years, driving anything from dynamic speakers (sometimes even two per side), to planars, to the very demanding electrostatic models with ease, and have never even blown a single fuse.
If you haven't heard or seen any amplifiers from Clayton Audio, there are several reviews on www.SoundStage.com, amongst others.
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Most of the older Krell class A amps worked fine into this load, and are pretty cheap these days. Not the last word in sonic refinement, but pretty bulletproof.
McIntosh MC-352 will carry all loads, no problem, and have excellent sonic characteristics! $4,500 amp can now be purchased preowned for about $2,750, new, on the net with no warranty for about $3,200.
It would help to know what you are trying to do with the amp and your budget. For a budget audiophile like myself, McIntosh and Krell, even used are way out of my price range. I do know that the good old Adcom GFA-555II is rated at 325 watts at 4 ohms x2 and can handle a two ohm load. And at $350 -$400 for a used one is an affordable one.
I drive a pair of Thiel 3.6s, that are pretty inefficient and are said to go down to around 2 ohms, with a Conrad Johnson MF2500.
I am in the process of getting a new,and I mean new,pqir of NEAR M50's setup.If you had the review of Stereophiles report on the stock version you will find that the Impedance drops to the 2ohm range.
I will be getting the M50's that incorperate a new Crossover network and possibly newer driver's as the person I am getting them from worked with NEAR and is in the process of starting up a new company that incorperatres NEAR technology!
To be on the safe side I want to have an amp that is capable of handling that type of load and which is Solid State.
I have a Modified B&K ST202 .but I do not believe that shall beable to handle a 2ohm load.
Naim Audio amps will drive anything. They have no problem with loads under 2 ohms. 2 ohms and above are a breeze. They may not look real fancy, but brother, they can drive a speaker. Also, they have a very conservative power rating. They typically have 4.5db of dynamic headroom, which means they can produce 2 and a half times their rated power when required. Not Class A power, Class AB, but nice sounding with punch. Not terribly expensive, but not cheap.
Wolcott Presence P220-M Mono Block 220W Tube Amplifiers are rated at
2 ohm load- 220 watts, 12 Hz to 20 kHz.
4 ohm- 220 watts, 16Hz to 30 kHz.
8 ohm load- 170 watts, 20 Hz to 30 kHz.
close to your requirements and a sweet/powerful setup.
How about an Adcom 5802 or a Bryston 3Bst or 4bST?
Check Symphonic Line power amps. They can remain
stable down to 1 Ohm. There a RG4 monoblock for sale
on audiogon right now. Sounds better than Levinson
and Krell by a big margin. Check it out!
The McCormack DNA2 (or deluxe) is rated at 300 wpc into 8 Ohms, 600 wpc into 4 Ohms, and 1200 wpc into 2 Ohms. This is a sweet powerful amp, and can be had for around $2500. used. Steve McCormack can also "optimize" this amp to drive 1 Ohm or 1/2 Ohm loads. I've used this amp (now Rev. A) for several years. Good Luck and Cheers. Craig
Innersound esl amp delivers 600 watts into a 4 ohm load. I'm using the esl amp to drive my maggie 1.6's with great results! Check it out at www.innersound.net.
Also meant to say that the Innersound is stable into a .5 ohm!
All the above suggestion are valuable. I second the McCormack. I could also suggest Classé, specially the older DR series or for a lower budget the Sunfire amps. What speakers exactly do you want to drive?
You don't need a three hundred watt amp to drive a two ohm load. There are other issues just as important. How large is the room you are using. Is the acoustic enviroment bright or dead? How loud do you normally listen to music. What is the speaker sensitivity. Martin&Logans go down to one ohm and I have heard them driven by quality 100 watt amps. Look for a solid state amp the doubles it's rated output as the resistance is halfed. Also high current tube amps can drive low resistance loads. When in doubt ask a dealer to loan you an amp to try. Good Luck!
Glad to see there are alot of Audioheads thinkin of this stuff as It becomes a virtual maze of what is able to do what!
I will look at all the post to determine what might be the most musical to my ears!Wish I were a reviewer so I could do the sampling of so much fine gear!
Cheers and happy listening!
Look, first of all the 2 ohm load is more than likely in a very narrow frequency range. I don't know of any speakers that are nominally rated at 2 ohms. Secondly, the sensitivity (efficiency, if you like) is another consideration. Thirdly, the phase angle of a speaker should be another consideration. Some other posts mention room acoustics, etc. So it seems it is not such a simple answer.
Of course, you could always by some brute force amp and probably not concern yourself.
My own experience is using 60w tube amps to drive Acoustats and Magnapans to very satisfying levels.
The speaker mfg certainly could suggest the best type of amp, but any good amp that is rated for 4 ohm loads will probably work just fine.
If 2ohms are in the common spectrum for yr speakers, I would make sure my amp is optimised down to about 1ohm (see garfish above) or go with products that take low loads into account; Symphonic Line RG4 is one such product (see Rulee, above). Of course, you need to like the sound too!
If 400 watts into 2 ohms would work for you, a CODA Continuum Stage+ amp would be an excellent choice. It's stable into fractions of one ohm. Has powerful, tight bass and great delicacy in the mids and highs, too. See this site for more info:
The McCormack is nice as Craig suggests. I would add the Sim Moon W5 and the Blue Circle BC26.
one I know, proved to be relible is from audio by van alstine.
there are 2 models solid state andvaccum tube hybrid.
avahifi.com is their url.1600$ about 160 watts.
For an amplifier without a sonic signature that is stable "with any load," I recommend the Pass Labs X250. The smaller X150 may do it, but the X250 definitely will. And at 2 ohms, the X250 is rated at a 1000 watt output.
A Perreaux 350 amp or a "load-invarient" Sunfire will handle this requirement quite economically
Best Bang for the Buck, Classe Audio CA 300 used or the new 301. Built to last a lifetime and the sound is superb!