Responses from daverz

Vandersteen Treo Speaker Cable Suggestions
Another vote for Anticables ("true" bi-wire configuration).  The stiff -- though quite malleable -- wire makes it easy to keep the cables off the floor, and I really like the "medium" spades they use on the Vandie end. 
Tidal and Squeezebox
Instead of another Touch, I recommend a Raspberry Pi with piCoreplayer.  Very easy to put together and set up.  And a Digi+ card if you want S/PDIF output.   https://sites.google.com/site/picoreplayer/home 
how do you set VTA onthe SME 309 tonearm?
VTA is adjusted while the clamp bolts (the bolts that lock the rack slider also lock the pillar) are loosened. 
amp for vandersteen Quatro maybe vandersteen 5a
Try to audition Rogue tube gear if you can. I use a pair of M-180 amps. Very natural sound and easy maintenance. 
6922 tube selection
If you're going to spend $46 per tube, then I would try some of the NOS tubes that Upscale Audio or tctubes offer. I didn't find the Genalex anything special, and the ones I had were not very quiet. However, this sort of thing is very circuit depe... 
Preamp tubes... Psvane or Genelex?
I would suggest some RCA Clear Tops. 
What is you TIDAL setup?
I'm using ickStream, iPeng, a Squeezebox Touch, and an Auralic Vega DAC.There's a big downside to this in that the Tidal library is not at all browsable using ickStream. There's no ability to "drill down" beyond the 100 items listed for a genre (a... 
Vandersteen 5 HP Filter settings for RCA unit
Input impedance specs can be a "nominal" value, and the actual impedance can drop in the bass frequencies. So I would always check with voltmeter readings taken at the amp outputs for 100 and 1000 Hz test signals (you want the ratio of amplitudes ... 
Classical music comps
Get the Decca Sound box:http://www.amazon.com/Decca-Sound-Analogue-Years-Limited/dp/B00E0H8KAQGreat repetoire, great performances (with only a few clinkers), great Decca sound. 
Borodin String Qtt 2
Here's a Decca CD with the Tchaikovsky 1, the Borodin 2, and the Shostakovich 8:http://www.amazon.com/Tchaikovsky-String-Quartet-Borodin-Shostakovich/dp/B00DPH7RKQ/The Lp with the Shostakovich backed by the Borodin should also be easy to find. 
classical music source
I agree with Larry's comments. You can always rip CDs later if you want to serve your music up via computer. Building a worthwhile classical vinyl collection takes real skill IMO, and you miss out on the last 30 years of recordings. 
Seeking more 3d imaging, deeper/wider soundstage
I'm not familiar with the specifics on the Quads, but 89dB and 6 Ohm nominal does not sound like a difficult load for, say, a 100 Watt push-pull tube amp (using the 4 Ohm tap). Do the Quads have some wild impedance swings that make them unsuited e... 
Listening Fatigue & Speakers in Small Room
I'm not familiar with the 6H23 (I use EH 6922s, which are what my 3iX came with, but I don't think they are the thing if you have "hot" tweeters). You might want to talk to Kevin Deal about mellower tubes in the 6922 family. The Genelex Gold Lions... 
Listening Fatigue & Speakers in Small Room
I also suspect the speakers, but I'd try some tube rolling first. Maybe some current stock Gold Lion 6922s. For the 6V6, maybe some Pope NOS or the current stock Tung Sols. 
Seeking more 3d imaging, deeper/wider soundstage
Have you considered tubes? Something like a Rogue Cronus integrated or their Atlas amp. (Neither have XLR connections, which are rare on affordable tube gear.). Rogue's tube gear is easy to maintain.