Until you've played every transistor, digital and mosfet head in existence you can't make such claims.
All of this thread seems to be preference based on little experience. Confounded by typical guitar buyer rhetoric that we've been fed so much of that we can't help but repeat. Like a bunch of brainwashed imbeciles.

I think a better way to describe what I perceive to be "liquidity" while playing a tube amp has to do with tube microphincs:

"All tubes will exhibit some degree of microphonics. Microphonics do not mean that a tube is unusable. You just have to screen them a little closer and determine where they are best suited for use. Input pre-amps are the most sensitive areas of the amplifier. When used in this application most tubes will generate some noise if you tap on them with a pencil during operation. Keep in mind that doing so can actually damage the tube and make it more microphonic or cause it to fail if you hit it real hard. Although they are screened prior to shipment a tube is an electromechanical device and can be damaged during shipment. A microphonic tube will ring, howl or produce general feedback problems. It will be more noticeable at louder volumes or when used in close proximity to a speaker, typically in combo amps."
http://thetubestore.com/12ax7review.html

The reason SS sounds sterile is the lack of simulation of tube microphincs, tube microphonics being influenced heavily by the sympathetic vibrations from within the playing area...the speakers, the guitar body and strings, etc., everything in the playing area will vibrate with or against the tubes.

SS needs to make a transistor that acts as a tube microphonics sensor to simulate tube microphonics to create a convincing tube feeling and sounding SS amp.

I'd shed heavy, hot tube amps for a SS amp that can simulate everything about a tube amp including tube microphincs, which is the only thing missing from SS where I'm sitting.

...soon, we'll see an adjustment for tube microphonics in SS amp simulators to adjust and tailor the saturation, type, and amount of the room vibrations the sensor picks up like a tube would from the room where the amp sits, us being able to adjust the "liquidity" of the feel and sound to facilitate ease of expressive, dynamic playing via enhanced sustain, over-tones, and feedback where you can use a delicate touch or gritty dig in a relaxed state like you can with a real tube amp but not a SS amp. Done.

If that don't makes sense...

Far as that one's concerned, it would be quite easy to design a test, and sooner or later I'd like to take a crack at it. Of course, it couldn't be me who then performed the test, or it wouldn't be a double-blind.
Cheers - C

Great thread. Although I have nothing technical to contribute, it's a good read and an education.
Keep it up gentlemen.
You guys are heaps cooler than Train-Spotters and Trekkies.

What test equipment can detect "sympathetic tube vibration"?

[b]Scientific research vs. Personal Anecdotes vs. New Age Vibronics...There is a bit of indescribable "vibe" and "feel" to certain devices and pieces of equipment...I agree there is something special about a tube amp that is hard to find in a solid state...RCB, I think that's what you are trying to describe, but I have to agree with the Ninja; to dismiss an entire type of equipment based on a tickle in your pickle is somewhat short-sighted...

Informally, me and my fingers and my soul of souls, where the music is, can detect this tangible, mechanical effect.

Formally, any highly sensitive motion sensor...no, not like we use with alarms, we're talking scientific ultra sensitive (can detect mouse farts), something that can pickup up vibrations ping ponging back and forth between the tube amp and the rest of the room contents, possibly a smoke filled room, a slow-mo video showing the smoke being affected by the sympathetic vibrations.

An oscilloscope shows the difference between the tube state and SS sine waves, so...the sympathetic vibration are there, everybody overlooked it I guess and now we just need to dig deep and get the technology going.

BTW, I love the vibe of this thread...I'm getting some really cool sympathetic vibrations and I feel all liquidy!

And no, I am *not* Joshing here. I am...(hypothetically) holding a Leo Fender prototype tele type serious -- this is a sacred act I am doing here and will have a huge effect on the outcome of SS technologies simulating tube amps.

I'm trying to nail down what you're talking about.

Are you saying that the micro-phonics of a tube will pick up the sound waves from the speaker (or other sonic sources), which then physically disturb the tube elements (plate, grid, cathode, etc), which in turn modify the signal? This is conceivable but I seriously doubt such a feedback loop could cause the "liquidity" that you claim.

The affects would be far more subtle than any parameter typically considered in amplifier design. Not to mention the fact that no two tubes share the same micro-phonic properties. I seriously doubt this could be detected on an oscilloscope. I'm willing to be corrected if you can show it and not just assert it as fact.

Cheers,

I'm trying to nail down what you're talking about.

Are you saying that the micro-phonics of a tube will pick up the sound waves from the speaker (or other sonic sources), which then physically disturb the tube elements (plate, grid, cathode, etc), which in turn modify the signal? This is conceivable but I seriously doubt such a feedback loop could cause the "liquidity" that you claim.

The affects would be far more subtle than any parameter typically considered in amplifier design. Not to mention the fact that no two tubes share the same micro-phonic properties. I seriously doubt this could be detected on an oscilloscope. I'm willing to be corrected if you can show it and not just assert it as fact.

Cheers,

"All tubes will exhibit some degree of microphonics. Microphonics do not mean that a tube is unusable. You just have to screen them a little closer and determine where they are best suited for use. Input pre-amps are the most sensitive areas of the amplifier. When used in this application most tubes will generate some noise if you tap on them with a pencil during operation. Keep in mind that doing so can actually damage the tube and make it more microphonic or cause it to fail if you hit it real hard. Although they are screened prior to shipment a tube is an electromechanical device and can be damaged during shipment. A microphonic tube will ring, howl or produce general feedback problems. It will be more noticeable at louder volumes or when used in close proximity to a speaker, typically in combo amps."
http://thetubestore.com/12ax7review.html