6SN7 tubes and variants question.

 My RCA JAN 231's are the smoke glass not the black.

@billpete, I think that it is quite possible that we are talking about the same tube, but I am mistakenly calling them "black glass."

I'm waiting for a pair of Sylvania VT231's that I found a few days ago. They are also labeled 6SN7GT. Not sure if they are the bad boy or not. I have to study that a little more to understand which is what. I think the BB's are silver bottom if I remember right and I don't remember what this pair looks like. Seems to me they are silver bottom but the seller never called them bad boys so maybe not? I am still kind of anxious to hear them. 

I know that there have been some threads on identifying the Sylvania "bad boys", I think if you plug that nomenclature in as a search engine in the 'search discussions' box, you should get some hits.  Regardless, you jumped in with both feet on tube rolling with that SLP98--you have my respect!  I am looking forward to your follow-ups.

@immatthewj 

Well, I hope we are talking about the same tube. The RCA JAN VT231 does get a lot of praise. My National Union pair has much darker glass, literally black like the Tung Sols. The RCA VT231's have a dark gray smoke glass which appears thicker in appearance than the RCA GT smoke glass, which is slightly lighter in color and apparently, the amount of smoke color. I have yet to listen to any of these but looking forward to it.

It looks to me that the Sylvania BB's are black plate. Some people like to brag up how many holes, Brent Jessee says they both sound the same. I've also seen both tall and short bottle and even Chrome top as BB but I think some are probably wrong. The credible ones all fetch $200 a pair and up. The Syl VT231 pair that I just picked up is gray plate. Probably not BB but I think I've read that they can sound very nice, Any of the VT231's get high praise so it appears. They would all be early to mid 40's to very early 50s'. One other difference can be the getter, type and placement since we find top, bottom and side getters all offered in 6SN7 variants. Not sure which the BB's should have but it seems like bottom from memory. Will have to check. 

@billpete Sounds like you've got some nice tubes.  I've read many tube rolling threads and don't recall any warnings about 6SN7s being incompatible with any gear.  I think you're good to roll.

@tomcy6 

Thanks. None of the crazy money tubes in the 6SN7 collection yet but many that seem favored and many that sound very good. Just tried the National Union pair of GT's last night and they sound very good. Nothing stood out as unusual, just a pleasant listening experience. Maybe piano sounded a little more natural than others I've tried. Bass was good and strong. Detail, air, all present. None have blown me away with soundstage but my speaker placement may be more at fault. They are quite far apart. I may try moving them closer together. Having them on the long wall in a rectangular room is less than ideal.

@billpete There used to be a tube dealer who wrote on his website that neither he nor anyone else could tell you how a tube will sound in your system.  Experimenting with what you have may be a better way to getting good sound than shopping for expensive tubes.  Enjoy!!