People who are Irrationally Afraid of tube amps

"70 watts at 2 percent distortion, with output impedance of 8.7 ohms, and all for a mere $4500. Sorry, I don't think my Maggies would like that"

Elhartford, first hand I wouldn't know but it is my understanding that David Berning was using one of his amps with Maggies and I have heard from others that it works quite well although it wouldn't seem so. You are quoting the spec for the low feedback setting, you would probably have to use the normal setting with Maggies.

I suppose if specs were the be all end all of what we hear, most well healed audiophiles would own Halcro amps, they don't and some suggest it has a "sterile" sound. Reminds me of the 30K Denon amps from 10 years back or so that I heard, extremely wide bandwidth with ultra low distortion specs which is how it was marketed. Bottom line is I hold very little value in specifications when listening, the design, application and end result is what really matters. While it is quite easy to hear the 2nd order harmonic distortions in many tube amps, there are other designs where this is less apparent. Tube amps definitely have their limitations in many applications without getting into the humongous beasts that require huge transformers, many tubes and costly maintenance but a viable choice for those that have difficult loads that would pass on SS.

I'm not knocking ss, I haven't heard them all and it is evident that they are improving and if they provide the magic of the illusion to those that listen, bravo, that is all that matters. I would love to hear a ss amp based system that provides the magic I have experienced from some of the great tube systems I have heard, I haven't to date, just good sound.

And Slappy, when you finally get around to tubes, which I am confident you will, just make sure it has a cover to keep that mischevous dog from temptation.

Kana & Twl: can you post a link to the threads on Audiocircle that you are referring to ?

El: tubes are VERY much alive in high powered RF and in the music industry. Just ask a "rockin" guitar player. Sure, some of them use SS amps, but a huge portion still cling to and are drawn to the sound of a Marshall, Ampeg, Hi-Watt, Orange, Fender, Mesa-Boogie, etc.. tube head. Even some of the Peavey amps use tubes to great effect to obtain their specific gain characteristics and tonality.

Tubegroover: Low distortion can be achieved two ways. One is to build a very simple yet well designed wide-bandwidth circuit that is relatively stable into the intended type of load that will be used with it. This can be relatively costly as it is harder to keep a simpler circuit stable into various loads and do so while retaining wide-bandwidth. As such, it may require a lot of R&D prior to arriving at a suitable design.

The other method that is FAR more common is to build a pretty decent circuit and then try to correct any deficiencies in linearity with gobs of negative feedback.

The second method is a LOT cheaper than the first to build, design and market. As one might surmise, the cheaper one almost always sounds worse but is more stable over-all, hence the use of such approach by most mass production manufacturers. I think that Halcro tried to combine both approaches but probably used too much negative feedback in order to obtain phenomenally good measurements in specific areas. One could probably add a great deal of "musicality" to the Halcro by changing a few caps, etc.. internally. Just a guess though.

As a side note, I find that i like a lot of Nelson Pass' designed amps. The funny thing here is that they don't have "killer specs" in any specific area*. The distortion is surely not "ultra-low" nor are they phenomenally "fast" in terms of rise time or slew rate. As such, i think that Nelson tried to achieve the best of both worlds i.e. some of the more desirable sonic attributes of tubes with the better measurements and bass impact of SS. From what i can tell by the specs, he seems to have found a compromise between the two. The specs appear to fall somewhere between the two different types of products i.e. lower distortions and faster response than most tube circuits but higher distortions and slower responses than the "best" ( in terms of specs ) SS amps. Has anybody else ever taken note of this or shared these thoughts ? Sean
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* Other than price : )

Sean...About the pop music performers using tube gear..if the naturally-produced distortion isn't enough, they have a gadget that makes more!

About the RF application...My hearing range does not extend to RF. But, seriously, when Transponders for light aircraft first came out the circuitry was all transistors, except for one Traveling Wave Tube. Guess why the thing was frequently in the avionics shop. Now they (ours anyway) are all solid state.

Tubegroover...What's the point of this amp if you can't use the low feedback configuration. Also, according to Twl, the distortion characteristics of a particular type of speaker (single driver full range) are necessary to cancel out the amplifier distortion. How does this work with Maggies?

What is boils down to is $$. I've auditioned over 100 SS and tube amps combine. There are plenty of good solid state amps that performs as good as some of the best tube amps. However, the price for the SS are always outrageously higher than the equal performance tube gear.
i.e. If I need SS 100Watt power amp that can be better than a HK Citation II, I'll need to spend at least over $2000 in SS amp to achieve to same sonic performance.
Anything less just doesn't cut it.
The cost of a vintage HK Citation II is only arond $800. In the silimar price range SS amp, thin, dull, dry and flat sounding SS amp are not my cup of tea. It just doesn't have the same bandwidth as the tube gear.
However, if you're talking about current production tube amp, the price tag is much closer these days ( the manufacture jack up the price on tube gear since it is "HOT". In any case, I still prefer vintage tube gear.

Just my 2 cents

Sean, here's the link to the audiocircle discussion on the digital amps.
http://audiocircle.com/circles/viewtopic.php?t=5123

There's about 9 pages of discussion on the apparent poor measurements and good sound reports from it. John Curl and Brian Cheney are involved.