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Re: Answser the question!.

I didn't say that tube DESIGNS were better than solid state, I said that A TUBE is better than any solid state device in many ways.
I lived with and used tubes in my hi fi system for the first thirty years of my life. I learned the fundamentals of tube design in college classes along with transistor design. Over 40 years ago I used to repair and maintain vacuum tube hi fi amps and preamps, at Berkeley Custom Electronics, (a high end hi fi store) while I finished college. For the first 10 years of my serious commitment to hi fi as an avocation, I used tube amps, preamps, and tuners almost exclusively, while I learned even more about designing solid state amps to compete with tube design. This is when I developed the complementary differential input stage, in 1968, and achieved distortion levels at 1W below .005%. Since I was using a K-horn, I didn't need more than 10W at the time. It had taken me years to make a power amp that sounded better than a stock Dyna mk3 power amp, but I still had a difficult time matching the sound quality of a Radiocraftsman 10W triode power amp. When I measured both amps, I found that they BOTH achieved .005% IM distortion at 1W slowly rising to .1% IM at 10 W, Neither had crossover distortion as I ran my transistor power amp at .5A quiescent current. They BOTH had a damping factor of about 40, and their frequency response both extended to 100KHz.
What could be the audible difference then?
My imagination? I think not. Then, I read the first paper by Matti Otala, in 1970, that promoted high slew rate, and high open loop bandwidth. I found that the slew rate of my l0W power amp was only a few volts/microsecond, because I had tended to overcompensate the dominant pole in order to get maximum stability with any capacitive load without a lead network or an output inductor. I had gone too far, but this did not effect the IM measurements. I modified the compensation to make the power amp a bit faster, and this did help it subjectively.
Now, why do I design solid state, yet give some credit to tubes? I design solid state, because I am good at it, and it allows more combinations of creative topology, BECAUSE it has complementary devices, lower noise, both enhancement and depletion mode devices, which allows more creative freedom (for me) to try different topologies.
Still, tubes give me serious competition, and I know it.

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