Tube vs. SS article and seems legit

[JBLAddict]

popped up in one of my trade publications for semiconductors. maybe one of you smart guys can summarize for the rest of us :D

http://electronicdesign.com/article/analog-and-mixed-signal/-House-of-Fire-Firebottles-And-Groove-Tubes-Versus-Devices-That-Find-Their-Origins-in-Sand-Part-1-

"Conclusion

I wanted to delve into the subject and try and explain some of the sound differences that were wrongly perceived as being purely related to the vacuum tube in both the purist extreme application and that of live audio and guitar amplifiers. We proved that the active devices are a fairly small portion of the observed audible differences by a drop-in experiment, which led to investigating the rest of the signal path and the output damping factor.
You can easily approach the “tube-amp sound” by simply placing a substantial resistance in series with the output of a modern voltage-source audio amplifier. This decreases the damping factor and allows the bell modes on the transducer cone and dust cap to radiate as opposed to being clamped by an output impedance that is effectively zero."

[fpitas]

That article is a good start, but a bit incomplete, although I can believe that damping factor is a big contributor to sonic differences. He played with a push-pull triode amp, but as anyone who spends time on audio forums is aware, SET amps are considered the Holy Grail. Now, I'm willing to believe that once again the active device is only part of the equation; the output transformer, especially for a SET where it has to withstand heavy DC bias, is probably another contributor. The transformer is gapped so it has a large leakage inductance, and the DC bias most likely leads to even-order magnetic distortion.

[speakerdave]

That article is a good start...."

Yes, then there are drivers with no woofer cones or domes, tube preamps . . .