Tube rolling Question

Hello Tube Rollers
I recently bought my first tube preamp (Blue Circle 21.1). I've noticed I am need of new tubes as the tube whoosh is considerably more noticeable now than 6 months ago. The amp comes with  Electro-Harmonix 6sn7 tubes which I appreciate and dig the sound. I will certainly replace these with a the gold pin model as I like the sound profile. Here's my question:

What other tubes might you recommend for a different "flavor" of sound, and just to have fun with. I am a poor audio guy so please no recommendations for tubes that will cost more than preamp. 

Thanks in advance. 
 You should give vintage GE or Sylvania a try. They can be had at very reasonable prices, so you can roll without spending a small fortune. BTW, I use all GE preamp tubes and I like them over others that I have tried!
Brent Jessee sells quality NOS vintage tubes. Here is a comprehensive description of the sonic signature of each brand of the 6SN7 tube.

My recommendation for a new tube roller would be to try RCA. Classic lush sonics with an open sweet midrange, very good dynamics. A 6SN7GTB is very affordable.

Amperex Holland are more expensive, but they make some cost effective types. Incredible 3D soundstage with airy highs.

2nd the Sylvania route. Also new production Sophia Electric 6sn7s are very good to my ears
Some good info can be found here: Having tried the top twelve on that list, I’ve been using the Tung-Sol, Round Plates and Sylvania 6SN7W, metal base tubes for years, with no desire to move. SO GLAD I bought a few, before the prices went nuts! Some, that provide almost all the nice attributes as those, but- don’t sell for nearly as much, are the 1940’s, bottom-gettered, Ken-Rad(JAN-CKR) and bottom-gettered, Sylvania(JAN-CHS), VT-231/6SN7GT tubes. The balance of those twelve(that I tried), were all too warm/colored(for my taste, anyway). Here’s a very reliable source:
I'm using the Tung-Sol Round Plates, 1940s and they are wonderful. But at $275 per tube for low noise low microphonic, it's a major expense.