Tube Rolling with 6SN7 tubes...?

5692 RCA "red bases" have a seductive and sweet midrange. They do not, however, allow for higher plate voltages (which means that if a GTB is reccomended because of higher plate voltages, the tube life of the red base will be shortened). NOS Sylvanias and RCA's are plentiful at reasonable cost. The KenRad's in my opinion have the best bass control. The Tung-Sol round plates are the all round winner, hands down, but, unless you happen upon them serendipitously, expect to pay through your nose for them. By all means, try as many as you can, tube rolling is fun! Happy Listening.

Here are a few options.
RCA VT-231, I think the Grey glass tubes are closser to what you want than the black glass.
National Union, I prefer the black glass but think from your post the grey glass again would work for you.
The CBS brown base has a sweet midrange.
The KenRad VT-231 has a nice midrange and very good bass.
The Brimar CV1988 has a nice midrange also.
You can go www.head-fi.org and do a search in the amplification forum for a thread titled
The 6sn7 reference thread
It has about as much info on these tubes (and all 6sn7 tubes) as you will need.

...and here...

http://www4.head-fi.org/forums/showthread.php?t=119638

...is that 'N7 reference thread.
.