The ups and downs of tube vs. SS...

30+ yrs ago I had a major love affair with tubes in my big living room system: 2 X RM9 tube amps; each w/a pentode/triode switch at base of each of the 8 tubes (EL34 or KT-88). Had a big SS amp on the subs, tubes on everything else...+ a VTL "Ultimate" preamp (tubes).

What is it about tubes? Easy to hear, not so easy to describe. It's a quality of dimensionality, 3D sound from each note. You hear the body of the violin, the rosin on the bow, not just the sharp starting transient of the note. The notes are in space, and there's space around the notes.

Yes, tubes cost. And yes, they tend to poop out a bit on the very bottom and top. Top isn't a problem, since so much else in the stereo chain is over-hyped in the treble to begin with. Bottom can be a problem--that's why I segregate deep bass w/subs driven by SS.

All these years later, just bought my 1st desktop/headphone audio tube unit, a Woo WA3 OTL headphone amp w/preamp outs. It's burning in. Even listening on the "wrong" headphones (ones that aren't high impedance), I can already hear those familiar 3D notes.

I bi-amp, with a tube amp powering my planar mids/ribbon tweeters, and a SS amp powering the cone driver woofers. Best of both worlds, I feel.

But I agree with the people above, like Atmasphere - low order harmonic distortion is the way to go.

For instance, 2nd order harmonics are an octave above. Very rarely in tonal music is adding an octave going to destroy the vibe or harmonic tension/relaxation (dissonance/consonance). I mean, when I write orchestral music, I often ADD instruments in octaves above, to add the warmth and dimension to the sonority!

7th order harmonics, on the other hand, are a diminished 7th (plus 2 octaves) above the fundamental. The odds of this frequency aligning with the musical content you are listening to, is very small. You are going to perceive this as hash or congestion or listening fatigue.

Hope this ramble helps. It may be totally wrong. Jim, I'm a violist, not an acoustician!

I've had a tube preamp from 1990 on along with a SS amp.  I've been very satisfied with the sound, BUT...I now have a TRL DUDE preamp with several upgrades to it and Nuforce Ref 9 V3 SE mono amps with the TDSS Level 3 upgrades including the power supplies.  The sound is to die for in all ways with VMPS RM40 BCSE MLS speakers that are very detailed.  The Ref 9's sounded very good prior to the upgrades, but are now way beyond their stock form in sound.  Many VMPS users like tube amps on top and SS amps on the bottom with an active crossover.  Just being honest.  This last combo is quite a bit more expensive, however.  I've heard my amps with a couple different systems and they are quite spectacular in each.

atmasphere - yes!  That was the show & yes, I felt that the fi 2a3 monos did sound best; however, every amp sounded pretty amazing to me. 

Quite a bit of stereo celebrities in that room that day.  Actually, at the time, I was just getting back into audio as I took a couple years off when I became a father 4 years earlier.  On that day, I purchased a Creek 5050 int amp from Listener magazine's Rob Doorack that he brought with him that day. 

I was so amazed and impressed with what I was hearing that day, hence my name a'gon name Lou_setriodes!  

Like dorkwad, I have the solid state NuForce Ref 9 V3 monoblocks with new power supplies modified by TDSS, but combined with a vintage Conrad-Johnson PV 11 tube preamp.
I agree, the Ref 9’s are pretty amazing especially when coupled with the sweetness of the tubes in the CJ.
  
 Impressive power in a velvet glove!