They don't. The problem is that a lot of folks who think tube units sound like solid state and v/v are only hearing tonal response. There certainly are warm SS units and cold tube units, but that has nothing to do with the qualities that most tubeophiles recognize as the valued difference, such as lack of grain, liquidity, and airness of the high(er) frequencies.
Solid state and tubes are like sailboats(tubes)and power boats(ss)they both enjoy a common medium but ner the two shall meet.Or the classic phrase may apply "you can't compare apples with oranges"
They are intended for people who have good speaker systems. The intent of the lessor designs, is to take you mind off of what you don't have, by applying what is know as the "masking effect" (-:
Some solid state Carver pre-amps, like the c-6 provide dual preamp outputs: one SS and one that emulates a smoother, tube-like sound. I have used both to best effect over the years depending on the associated gear.
The vintage Carver stuff provides some nice flexibility towards a more tube like sound anchored in SS but is not a substitute for real tubes.
Some Carver SS power amps like the m4.0t and the m1.0t are designed to produce a warmer, smoother more tube like sound as well.
I have found the Carver pre-amps (c-6 in particular) provides these and other very distinct and useful features that I have found most useful for tweaking the best sound out of various gear over the years.
It is all about 'marketing', 'marketing' and more 'marketing. Tubes always sound best, my opinion. But in the end it is the speakers that rule, and the electronics should be matched to there needs.
Tube Audio Design makes a ss amp (Hibachi) for those who like the TAD sound but don't want to deal with the perceived hassles (hot surfaces, maintenance, reliabiluty, etc) of tubes. The Hibachis also offer more output. The company claims that their ss designs sound similar to their tube units with modest feedback applied. IMHO, the Hibachis indeed sound more "tubelike" than many tube amps I've heard.
THe answer is probably marketing....and the need to continuously offer something a little bit different.
Nice system. I am a Bob Carver fan too....I use Carver amps in my system also.
FWIW the underlying mechanism here is called negative loop feedback. It is a design device that is often used to reduce distortion. The problem is that in doing so, it is not perfect and actually *enhances* certain odd-ordered harmonics that the ear uses as loudness cues.
These artificial loudness cues are detected as 'hardness', 'harshness', 'brightness' and the like. Negative feedback can be used by both tube and transistor preamps. Those tube preamps that use it to excess will likely get a reputation for sounding 'solid state' whereas the careful transistor preamp designer can get his preamp to sound 'tube like' by limiting the use of feedback.
Component choice can affect things too, so its tricky to ascribe things entirely to one source. But in general you will find that feedback has a high collerlation with 'transistor sound'.
Typical tube circuits have very few components in the signal path, and are therefore much more transparent than SS designs. Victor Khomenko of Balanced Audio Technology has simplified the circuits of BAT's SS units, re-thought/re-designed their power supplies and helped them achieve a level of transparency/liquidity equaling that of some of the best tube designs. Well worth the audition. I'm a die-hard tube lover, and using his VK-D5 CD player, but- still a fan of his SS design philosophy.
There is an openness of sound that tubes are capable of that transistors have not yet achieved.
The only real downside to using tubes in amplification devices is related to driving lower impedance speaker loads (4ohm and below). In a preamp, tubes can drive the high input impedance of a power amp, which is typically 20,000 to 200,000 ohms, quite easily. There is also no need for an output transformer in a tube preamp. All of this means that the preamp is an ideal place to take advantage of the sonic benefits of tubes with no real downside.
The best tube and solid state preamps are attempting to converge on the theoretical definition of neutrality, but they probably never will because it doesn't likely exist.
I'm a firm believer in the notion that the pre-amp is the better application for tubes rather than the power amp.
Mapman, it depends on the speakers. For example, something like a 16 Ohm speaker load might be better served by a tube amp.
Unsound, the funny thing about that is that transistors sound better on 16 ohms too. I agree with you of course :)
Give a listen to the Music Reference RM9 or RM10 run passive through a Noble or equally good POT. You'll hear all the benefits of tubes without a tube sound.
i think a more interesting questions is the following:
why do designers persist in providing more and more resolution until it hiyrts ?
why should one suffer listening to certain recordings?
too much resolution does not sound real.
i believe that the result of designers' attempt to peel back so-called layers of veiling and noise to reveal all of the musical and non musical details of a recording creates the phenomenon that you are alluding to, namely, the convergence in presentation of tube and solid state amps and preamps. i don't think there is a deliberate attempt to create this convergence. i think it is a result of increasing resolution.
there is an optimum level of resolution for human beings. too much or too little is less preferable than the "just right" level. unfortunately manufacturers and hobbyists alike do not know what the optimum level is.
there have been many experiments in the psychology journals which deal with the subject of stimul;us complexity and intensity. it is obvious that when the level of clarity increases there would be a change in stimulus complexity and intensity. maximum intensity and complexity are experienced as unpleasant.
I think some designers try to get distortion and frequency response to the best that they can, at the expense of other probably more important parameters. Tubes often take a more reasonable stance- 1% THD seems high for a transistor amp but is common for a tube amp, which uses less feedback (and consequently might sound smoother). You get more a little more distortion but less of the types the ear objects to.
The bottom line is you still have to trust your ears. The benchmarks for testing won't tell you if the amp is really going to work.
Taijitu (yin + yang)?
Perhaps, like many dichotomies, neither tube nor SS can truly thrive alone?
is ss the dark side of tubes ?
I guess in the the case of SS versus tubes it's a matter of perspective based on preference.
Is tubes the bright side of ss?
I think it's a mis-conception, brought on by the fact that many of todays tube amps have extended freq response....unlike those built in times past.
The same with solid state. This design, for the most part, has advanced past the grainy midrange, and chalk board high freq's of times past.
In truth...the best of each type do sound somewhat alike. Both have good bass, and good treble....the biggest difference is in the mid-ranges, (lower/mid/upper) midrange.
Some people can't hear these smaller differences (and the reasons for this vary) They need a products of yesteryear, to confirm that there is a difference...or, a new product...with designed-in colorations.
To my ear...tube amps "do not" sound like solid state? But then again...I don't think Krell amps are bright either?.
I think we read things, and then they grow legs.
I think there is a lot of truth in your statements.
Marty, FWIW I gave up my tube amp and went with the TAD Hibachis beefed up version. Sonics are similar to the TADs tube amps but, a bit more up front and quicker.I have a tube CD and preamp so that may contribute to the tube sound that I am hearing. For the type of music that I listen to( Classic rock) and my equipment (Vandy 2cesigs, tad150, eastern electric CD), it appears to be a better match. Makes the Vandys really rock. Haven't seen a review on this amp but, I will probably write one soon.