Are tubes psychological?

Sure, the psychological aspect is some part of it. The sound of a good pure tube amp (and there are plenty of not so good ones) is appealing for a good reason. Solid state amps distort primarily odd order harmonics. Even distortion that’s barely measurable on a SS amp can be distracting and annoying to the ear. Tube amps, while having a total harmonic distortion much higher than SS, they tend to be much lower on odd order distortion, and do so more on even order harmonics. Not only do most people find this less objectionable. In fact, this is why most every rock or pop guitarist use tube amps when overdriving for the "fuzz" sound.

Interesting question.  For me, they simply make Maggies live up to their potential even though I do use a SS on the bottom end right now.  I would prefer a tube amp there as well, but will have to save a bit of $ to get that D-76A on ebay right now.

No fair anyone buying it until I can!  I call dibs on it!

Oh, if you want to buy it and send it to me as a gift, I promise to give you all the credit here on the Forum.

Cheers!

If only we could measure psychological.

Neither loop nor belt.

We need expert opinion.

Let's hear what the moths say.

None.