tube suggestions/ brand new to tubes

@buellrider97- Mike, I've been running old DR Reflector 6h30s from the get go in the Veloce. When I ordered the unit, I insisted on them and Vytas delivered. At a certain point, I retubed and finding a matched quad was not easy- I got a set from the'70s, NIB, old stock originally supplied by Victor of BAT from back in the day. Now, those tubes are really impossible to find--they are counterfeited, phony labels, etc. 

I did the retube when I was tracing a noise several years ago, and for trouble shooting purposes, bought a quad of EH- they sounded terrible to me, flat, lifeless, no harmonics, no punch. I'm told the Sovtek version is punchier. 

I've talked to Vytas about this b/c he keeps my Veloce up to date and has some newer mods to allow me to run the production tube-Sovtek- and get more out of it. I will be doing that at some point simply to get out of the unobtanium nature of the old stock DRs. Great tube when they were somewhat available- now, yikes!

*As to circuitry differences, I understand that some other equipment relying on the 6h30 is not so particular about using the old tubes and sounds fine using modern production. The Veloce is a bit of an outlier, so my experience should be attributed to both circuit differences (mentioned by others above) as well as overall voicing (something that I find is particular to each system and its overall balance/sonic needs). 

Congratulations. Tubed preamps are the way into tubes. It's a wonderful world. 

I'd recommend listening for a few weeks. Get to know the sound, inside and out of your preamp. Then do some research... AI will likely outline generally which tubes will sound like what. Then you can proceed in which ever direction you want to go from your starting point. I would imagine over the first few weeks of listening a direction will slowly become obvious... and hence the tube choices. 

I also run an Aric Audio Jackpot.  At this point I’ve rolled 6 different brands of 5751’s but have not tried any 12ax7, 12au7 or 12at7’s yet in the input position.  Aric told me the circuit was designed best for the 5751 but obviously works with the other types.  He also told me generally how different the other tube types sound compared to the 5751’s. I have also rolled 3 different brands of tubes in the buffer position, RCA, Amperex and Mullard.  It was very surprising just how much different buffer tubes changed the sound.  I can give you my thoughts so far on the various 5751’s but you might want to PM me as it is long and a little convoluted as in the middle I had a power condition device go wanky on me and I didn’t know it. My general opinion is the same as Terry London said in his review for favorite combo which is a Mazda in the input socket and an Amperex Bugle Boy in the buffer section. 
 

I’d get at least 50 hours on the preamp and original tubes before changing things out. As previously mentioned Andy at Vintage Tube Services is great. He is slow but if you tell him that you don’t need matched pairs it should speed up the process. I hope that helps. Good luck.  And by the way, it is a friggin awesome preamp!
 

Jeff

Brent Jesse, well respected, just sold his business told me: leave the unit on, no content needed, for 60 hours, tubes break-in done.

After that, listen.

@signaforce , @larryi , @jjss49  

First, I would like everyone for their advice and suggestions. After listening to you all, I realized,  HOW much I don't know!!!!  The best advice from all is to listen for that maybe 100 hours,  to see the flavor that your listening to.

Upon first listening, my SVS SB 3000 was dialed in perfectly, and the sound from the Guarneri's was just right. SVS set at -10db (if that's is saying it correctly) had to really push the sub in the system to get the right BASS. 

As soon as I hooked up the Jackpot, with the same sub setting, it was really terrible, BASS HEAVY,  CRAZY. WOW, was I shocked, and not in a good way. I laughed and said to my wife, What did I do? She said calm down and adjust you SUB. I almost spilled my Buffalo Trace, which really would have been  tragic. Taking the wife's advice, I had to go all the way to -20db for the sub to be dialed in, I was amazed. However, after listening to Audirvana 24/192 Stairway to Heaven, and Metallica, Nothing Else Matters, I was PLEASANTLY surprised. The bass was far more detailed, and deep,and accurate,  the clarity of the Mid Range, voices, instruments was very evident. My impression changed immediately.  

After reading signaforce, larri, and jjss49's post., I am really focused on more detailed and dynamic presentation, as you all said my system is generally considered warm.  I will listen for a few hours this afternoon, if time permits. It seems from what I'm able to discern,  I would prefer that more detailed, dynamic sound,  which from what I can gather would push me toward Telefunken or Maybe Amperex (Bugle boy was suggested). I'm going to start looking later this week for a tube or 2 as a back up, should something happen prematurely to my supplied Tung-sol 5751.( input stage)  If any of you have one that you think would fit my musical tastes, please let me know about purchase. Thanks all so much! Robert TN