Hybrid - Tube / SS amp capable of sub 1 Ohm loads?
I've done searches and haven't found anything that really discusses this.
There are a few options that I've seen that are Hybrid that will do this, for example:The Conrad Johnson Evolution 2000.
That amp is getting old, is there anything more modern that will accomplish this? Am I chasing a pipe dream here? The Lamm series claims to be able to do it but it will not in reality. I know people that has had these and tried to run them on an Apogee Scintilla and it pooped out.
There might be some tube-amps that can operate with a such load, but they are more voltage driven, not current and the Scintilla needs current.
Im the west-coast distributor for Viola Audio Laboratories. Having said that, Viola makes two different models that can handle your requirements: the Symphony Stereo Power Amplifier (MSRP $16,000) and the Bravo MK II Reference Stereo Power Amplifier (MSRP $44,000). Both units are exceptionally high current designs.
Last year I hooked up a Symphony to a speaker that generally runs from one-half to one ohm. Though the speaker still wanted more power, the sound quality was incredible. If you are after a virtually inexhaustible supply of power, the Bravo is in a class by itself (this unit can also be bridged for mono). Last week, one of the Viola technicians told me that they just put a Bravo on the test bench with a one-ohm load on it they run it up to two kilowatts output and the distortion was only at .3%!!!
Take a look at Violas website for a description of each amp. Feel free to contact me with any questions.
Actually, there is an obvious solution. Rather than trying to swim against the current by forcing a conventional hybrid amp to operate into a load it was not designed to face, why not use an amp that wouldn't mind working into a 1 ohm load and simply use a tube preamp to get that great "hybrid" sound you're looking for???
I am using a custom built 6SN7 tube preamp to feed Nuforce 9V2 SE amplifiers. That combination would likely sound much better than anything suggested thus far and you wouldn't be taxing the amp's capabilities... Seems simple enough to me.
Tvad- You're right about the Stereophile results. At 2ohms the Moscode only put out 130W, this after putting out 250w into 8 ohms and 390 watts into 4 ohms. In reading Markotic's first post: It didn't register that he was actually using Scintillas, and I thought he might have a system that simply dipped that low at times(OOPS). Still- with the satisfaction guarantee, it would be hard to go wrong. If he was considering Lamms: It's unlikely the Moscode would be a contender anyway. I based my reply on the MOS-FET amps I've been using over the years to drive my woofers. You could practically arc-weld with them. Too bad a Zobel circuit can't be effectively used to raise an impedence(and still sound good).
Spectron Audio claims that Musician III SE is stable up to 0.1 Ohm Load - with headroom of 3500 watts over 500 msec. This amp is neighter solid state nor its tube - its class D and for its sound description look at their web site/review page and search Internet, including Audiogon discussion forum.
Don Shaulis, reviewer from Stereo Times (who bought his sample amplifier) and has difficult to drive Apogee Diva wrote:
" I have never heard Moussorgsky: Night on Bald Mountain/Pictures at an Exhibition [Telarc B000003CSH] before. Oh, I have owned the CD for years but I never really heard it before. The Spectron presented the softer passages with such inner detail they became seductive but the real surprise came in the crescendos. The peaks reached were a revelation. It wasnt that the Spectron could play loud, it was that I wanted the music louder. For the first time the crescendos were reproduced with full fury but no smearing or harsh edge that demanded the volume be reduced. Now, after many years, I finally get this fine recording..."
Don't flame me here. But you might consider a pro audio amplifier. The switch mode (Class D) pro amplifiers can deliver boatloads of current and are designed to work reliably into low Z loads. They have come a very long way in the past five or so years and some of the better designed units some very similar to the switch mode audiophile amps....seriously. Downside is that many (most?) are fan-cooled, so this may be an issue.
Dear Pete: Other than the JC1 that already recomended to you IMHO the ML 20.5s or 20.6s could/should be a great match.
These ML amps are pure Class A an not only goes down beyond 1 Ohm but put at 1 Ohm 800 watts and beyond specs these monoblocks have very high quality sound performance. IMHO till today these amps were/are onof the best amp design ever and you could find it ( second hand/used ) for a relative low price.
I heard a rumo(u)r that the CAT JL-2 can be configured to drive <1-ohm loads.....the Scintillas actually. This would be a HUGE improvement over the Wolcott. I ran with the Wolcott for a few years until I changed to a pair of JL-3 monos....not even close! So give Ken Stevens at CAT a call.
Maybe a (used) Anthem Amp 2, hybrid 200 w/ch. I know it can drive 2 ohms, however you probably need a specialist class A totally solid state amp for that punishing load. But you know that already. Think long rows of bipolar transistors, and huge heatsinks, old school amps. Modern high end amps are hampered by needing to be adaptable to home theater, they dont really make the current diesels any more. Van Alstine makes a hybrid power amp that he can adapt for tough loads also I think.
If you find a tube amp that can in fact do it and do it well, let me know. If it works with your Apogees, it would probably also work with the big Ohms in my system.
I'd look into the class D suggestion further as an alternative.
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