Best tube choices for Jolida Music Envoy

Just my "two cents" for Jolida fans...My pre is the L2 Underwood HiFi mod, which came w / NOS Brimar ECC83/12AX7s & NOS Mullard ECC81/12AT7/M8162s. Wonderful "McIntosh" musicality. I switched out the 12AX7s for Popes (Bugle Boys). Virtual sonic perfection! I then swapped out the 12AT7s for Miniwatts (essentially Bugle Boys). UNBELIEVABLE imaging and transparency! But a Miniwatt failed, and I now use Mullard 6201s in the AT7 position. I like the trade-off: slightly less 3-D, but more balanced w / my Maggie 3.6Rs. Ribbons & metal domes like a little dose of warmth. (The 12AX7 is the more important decision in terms of imaging, and I find that the Brit AT7s and the Dutch AX7s make wonderful music together.) Other good 12AX7 choices would be Siemens or Valvos from Germany, as I am told.) Don't let anyone tell you that a particular tube is "crap," or that it is too laid-back, too "fuzzy warm," etc. Another will say that the SAME tube is too forward / bright, etc! It all depends on your gear! This "subjectivity" is expecially true of the Telefunken 801s / 803s, and Mullards in general. In conclusion, pay the bigger bucks for an accurate and detailed 12AX7 and go for a less expensive and "warmer" 12AT7 in your Music Envoy. A matched pair of Mullard 4024s (AT7) can be had for $60 at Mullard, and cryo treatment comes free from Tube Audio Products (KR Audio Products). Also check out Tube World and Upscale Audio. Good listening!
My Jolida sounds spectacular after the second glass of wine and any night with a full moon.

Your rather unorthodox "upgrade" may be cost-effective, but with a significant trade-off: LESS than spectacular sound 353 days out of the year! (And I'm assuming the wine is cryo-treated Boone's Farm?) Jolida is one of the best values in high-end audio, but can also benefit from tube upgrades--particularly, European NOS. I guess some of us take our audio hobby more seriously than others...
A l'il humor dear fellow. My 302 was rolled around with some exalted NOS UK wonder valves. Not familiar with Boone's Farm but did try Yasgur's Farm - but to muddy. Cheers!
Found some Raytheon 12AT7's from circa '55 and paired with some GE 5751 from '63 the sound was beautiful, detailed, huge soundstage, 3d imaging... and I didn't even have a drop of vino.
This is in the Envoy preamp.
Everything is so "synergistic" dependent on other components, cables, tubes...

When stock, my Envoy Preamp was more detailed with TF ECC83's, and sweet/warm with cyro'ed Mullard CV4004's. Mullard 10M's did not sound good, and the GE 5751 were too dynamic in my system.

After Wally's custom upgrades (L2-L3), it was definitely two-three levels improved. But changing tubes had a much less impact than before. I am using a Canary CA301, and if I match the single 12AX7 in it with the 12AX7's in the Envoy, there is no net difference... including TF's, Mullards (many), 10M's, Pope's, Seiman's...

Phono was always best with cyro'ed Mullard CV4024's.

But every system synergistics are different. I finally have it tuned the way I like and am enjoying the music.