Tube Selection Help

I would describe my listenng and music preferences as similar to yours. Tube Compliment for VTL 2.5 is listed as:
2 x 12AU7, 2 x 12AT7. I would think your Sylvania's would be pretty nice but I have no idea on your 6350s. Black plates and D getters are a good start on most input tubes though IMHO. NOS Telefunken 12AU7s and Bugle Boy 12AT7s might be a nice combo to try. They are smooth and lively and let the amp's warmth come through. In your amps, I think the JJ EL84s are as good as you can do for new production, I have these in a Ming Da amp and were a big improvement over Sovteks. You may have to go to NOS EL84s to do better. I will let others recommend NOS EL84s. These can get pretty pricey but not as bad as NOS EL34s or KT88s. Overall I am betting your current tube set is pretty darn good.

However, if I had your Spendors, I might look to go to an EL34 tube amp(s). You will generate more power and they will give you a fuller sounstage and mid range warmth in spades. Sveltlana or SED EL34s are hard to beat for new production and sound great to me. I wonder if the EL84s are giving you enough power to drive the those excellent Spendors at I am guessing 20/25 watts per side.

Another upgrade you may consider is adding a good inexpensive DAC (V-Dac ii maybe) to your mix and bypassing the Regas and just use it for a transport. This would give you better sound and also give you stored music playback capability if you want to venture there down the road. I know that was not your question, just a thought.

Hoopster, thanks for your thoughtful response. You have given me some things to think about. My amps will go 45 watts in tetrode mode, but possibly more warmth would be nice. I will see if I can find an el34 amp around town to try. I wonder how much more warmth tube choice can bring me with what I have now? Happy New Year!

I have a set up similar to yours with a modified Fisher 400 receiver and Rogers LS3/5A speakers that I use to listen to Jazz, Country & light rock music. The system sounds great and has plenty of power provided you don't listen @ ear splitting levels. I generally listen to music at a moderate levels, enough to get the full sound stage out of the system but not so loud that it hurts my ears. I have never heard the VTL Tiny Triodes or the TL 2.5 preamp but have read nothing but good things about them. If you went to a EL 34 based amp you would need have 2 pairs per side since a pair of EL 34s only puts out about 40 watts depending on the amp, which is about what you have now.

I have a VAC PA 90 mono blocks with 4 EL34's per mono block, which I think would be over kill for your speakers unless you like to crank them up to 100 db range.

I think you would be better off talking with a couple of knowledgable tube dealers and let them make some recommendations on tubes. Andy @ Vintage Tube Services and Jim McShane @ mcshane design are two excellent tube dealers that I would recommend. By the way NOS EL34 tubes are about twice as expensive as NOS EL84 tubes. I am sure you can get a lot more out of your system with better tubes.

Good Luck,

I actually enjoy rolling tubes according to the music I'm listening to. Similar to using different strings on a guitar to change the sound. So many choices available.
I found Telefunken smooth plate 12ax7's to be loud and clear while Mullard's were mellow and deeper. Sovtek 12ax7lps's were horrible, Sylvania Gold Brand 5751 is my favorite input tube for my preamp (Sound Valves VTP101). RCA made great tubes back in the 50s-60s-70s and I have them too. Personally, I tend to favor military type triple mica /extra support rods input tubes because of their lower microphonic's. My point is that you should pick up an assortment and see what you prefer. Input tubes aren't too expensive and you don't have to worry about biasing.
NOS vintage El34's cost an arm and a leg. Mullard's are probably around $75 to $100 each but IMO have a more interesting sound than the current re-issues. YMMV.
Plenty of info out there. Read up about the different tube variants. For example 12ax7-12ax7a-5751-7025-ECC83-EC803S. Similar variations exist for 12au7's. Mix and match till you get the sound you want.

For the 12AT7s and 12AU7s I would go with Military Mullard tubes. They are readily available and the price is still reasonable. VTL really comes to life with those tubes. They use a different numbering system beginning with "CV".

Also, look for some NOS EI EL84s.