Having been duly reminded of the original question, and sobered by the objective (as he is new here) observation by Zork 52 , let us look at the original request:
zumbo said:
I am getting interested in the tube amps because of so much praise. I was thinking of building a 2-channel system. I have no idea as to who the mid-fi contenders are. Some of this stuff is just toooooo expansive. Some of it has low power specs. While drooling over some Manley stuff, I saw Rob Babcock mention the Butler TDB 3150. Now that has good power, and a decent price. So, what is a good direction to start looking (brands).
Yep, perhaps we have not replied to Zumbo's original need ..... But then electroncs have sometimes been a strange subject, taking a circuitous (pun intended) route to simple truths.
Yes (Zork), we did not always apply ourselves to the initial simple request. I have only read the Butler piece now.
I cannot contribute regarding experience of umpteem brands of equipment. I can, however, from over half-a century of design experience and seeing circuits. So, somewhat later: The description of the Butler is a prize piece of promotional fodder. Mercifully that does not make it poor. Actually it is a hybrid, but only said at the end, as if not to put customers off initially (they forgot to put it into small print).
So, careful of promotion. Only relating (over-relating) the good points (and in all fairness, one cannot expect otherwise), that in itself will not inform you of the relative merits of technology. E.g., that 'greatset of distortion generators, the output transformer' with a pair of EL34 tubes will only generate some 0,8% of distortion for 25W before global feedback. But there is advantage in the 'impedance converter' operation of MOSFET output stages. On the other hand ..... One can obviously not give a complete breakdown of everything in a post such as this.
So my effort at summarising (together with my previous post):
1. It is easier to design a "clean" tube circuit than a "clean" transistor circuit. Tubes generate less obnoxious distortion than transistors. But good examples of both are available (so a lot of help from this point).
2. Tube amplifiers (especially high power) are quite more expensive than semiconductors.
3. Tubes do "wear out" with use, although over years.
4. Properly designed tube circuits and properly designed semiconductor ones should not present an audible difference in clarity. I have designed many of both. No fundamental reason for the subjective descriptions of "slow, fast, expanded sound stage, sweetness, airyness" and other observations in either topology. (Although I do not denigrade such as "lies", but they are personal. Some will experience them, others not.)
5. Hybrids: Advantages of both technologies but also some disadvantages of both. I have never desired to design one.
6. Holistic view: A lot more is dependant on loudspeakers and room acoustics
and ears. Your taste.
But in summing up, I am also repeating. "Fingernails on chalk board" as Hifihoney said. Sorry (as long as amplifiers don't sound like that).
