300b, x45, 211, etc.

I heard a Mastersound 845 with a pair of JM Labs and a Hyperspace that destroyed the Cary Rocket I own... but you won't find one for $2500. BAT would be a different direction, but better... I don't know. I like the Manley Stingray, but it's not quite the same vibe as the Cary stuff. It's funny when you start to think about it b/c after about $2500 used the next jump seems to be $5000-8000; Mastersound, OTL's like Atmosphere or Graaf, or seperates which would be the same as what you've got, but with more power but not necessarily quiter b/c it's a single-ended tube amp.

I agree with greg except for the feedback thing - plenty of variable feedback in tube circuits, depending. Lower than solid state, but not negligible. And interesting about the 1610. However, another thing besides low power to think about with say a 2A3, despite how linear they are, they also are inherently very noisy. To which I would add: 45 tubes (even lower power than the 2A3) and the recording studio fav tube, the EL519, which is a little like the EL34 but more linear. I think only EAR makes a EL519 amp, and, well... EAR, not exactly a fan... So it's $8000 at least for an 845, a company that will irritate you in their treatment of customers like EAR, or a noisy low power tube for $2500.

True, Greg. I should have been clearer. There are zero feedback SET's, but I think it's more of a "differential of the circuit" except in the case of direct heated tubes - or am I wrong about that? I do think, for all the noisiness of a direct heated tube, they do have something "special" regardless of their own internal topology. And it's never so with transistors. I disagree with Dr. Chau about the 845, which to me is actually quite a transparent tube. Of course, I've only heard them implemented in Mastersound's amps with a Hyperspace/47 lab phono pre/Cardas cartridge. The thing I find cool about SET's and the reason I love using them, aside from just the fact that they are actually exotic (like a minty Giulietta Veloce, or a vintage 1930's Rollei camera...) is that the holistic approach is the only one that works b/c of the low power; do you use speakers that are really super neutral, like Joseph Audios or go for the total overload of richness like a pair of Proac's or something?

Rchau - Are you talking about the guy at Taurus Audio in the Bay Area? What a *GREAT* room that is, as in *WOW*. And a cool guy too. The only system I've heard I liked as much was an Airtight (the KT88 one, I can never remember their designations) with a pair of large Opera Piega's. But the turntable was not on par with a Hyperspace. I sort of remember the guy at Taurus saying the phono was 47 lab... but if he's your friend, maybe you know differently...

I started a thread "Lowest power amp with Joseph Audio RM33's" - I have heard of someone using a 2 or 3 watt 45tube SET with a Pair Harbeth 40's (was in 6moons I think) and getting decent, though not spectacularly loud results... but of course I got a guy who told me "100 watts solid state minimum"; which is to me what leads to this sort of view of SET as difficult and unreliable. No one ever checks the ohms on the speakers which even if it's 4 ohms minimum, should be workable at 15 watts, if they're good. It seems to me a pair of Revel M20's at 4.4 ohms minimum would work as well with a Cary 300b as a Levinson, and might possibly have good synergy (crazy rich mids, and extremely neutral speakers), at least for a cheaper system. So 6 ohms minimum to me seems like it should run just about anything... or am I hi-jacking the thread?

Interesting Glassaud, about the AES topologies.

I use a Rocket, and have never had any clipping at 20w in triode. Maybe during a test of the system or something, but not in daily use (at least to notice while listening normally). It's the original one with the 6922 inverters. I have found it to be superior in almost every regard to the design at 30w triode using the 12AX7 inverters. I've heard them next to each other, and found there was really no comparison. I like Cary - reasonable customer service, decent designs with plenty of options for retubing, including EL34's and 6L6's in the Rocket. But I wouldn't want it if it had that sluiggish sound with the 12AX7's. Of course I've have also found that by cranking the gain, and rasing the bias to about 220 from the stock 200 (something Dennis recommends actually) at the input, I can listen to rock just as easily as chamber music. I use a vintage phonostage with adjustable gain and equalization. It's solid state, pretty modified, run through a UL tube preamp, and it makes the gain pretty hot. It can get uncomfortably loud, but doesn't clip. The bass is also very tight run this way.

Of course, 20w is not 2-8w. But I do think the philosophy of "the first watt should be enough, the rest should be back up", is the best way to get a real dimensional life-like sound from a system, regardless of loudness, front ends, speaker pairings, etc.

I just use a pair of Paradigms for my speakers, which while not awesome speakers, are reasonably sensitive and good buys besides. I've heard many salespeople say (anonymously) that they bought them because at the end of the day they did many things right that the $3000-6000 speakers did wrong. My room is an L-shaped (yuck) 40 square feet, and the dispersion of the Paradigms is not laser tight, like it was when I was running them with Marantz mono's at 125w. They sound better, and more holographic at a KT88 20w.

The other great myth of SET's is that spec's are everything. It's one of those few times when you have to actually try it to really know if it works. Hopefully there's always a friend with a system to poach on to try stuff out, or a friendly audio store (or at least one that will put up with bringing in equipment - hopefully they are curious about what they aren't carrying).

About Klipsch - once the man, always the man. He and Bob Carver pretty much to my mind are two of the great contrarians of the audiophile world.

I hesistated to bring up the Rocket, but it is a cool design, and with the single-ended-like output (though not 100% there) it was definitely the way for me to get my feet wet and still have a lot of choice. I have toyed with getting rid of it, but never can quite pull the trigger when someone offers me money. I may go so far as to say it's Had's most original design.

Rchau - interesting about the 6SN7 topology and implementation with the 300B. Can you explain - I'm interested. What would the other ways of doing it be?

Interesting no one brought Gohzirah or the PX25. Two tubes I have not been lucky enough to hear.

If I were giving advice, which I don't, I would advise someone interested in tubes to find a really high quality integrated like a Manley Stingray featuring the EL84, if they weren't sure they would enjoy using tubes or were unsure about their competency with biasing, etc. Or I would suggest a KT88 amp like the Cary SLI-80 (comes with 6550, which is very similar and can easily be changed out with the 6550's sold). KT88's being the most lucid musically of the bunch. Then work towards an extreme - either single-ended topology, 300B, etc. I would not dive into tubes at the 845 end of the spectrum, unless I had more money than most, or was accustomed to changing out very high-end components every year or two - because if you hate your tube amp which is the size of a Yugo and puts out as much heat as a wood burning oven, you're still stuck with it.