6J2 tube rolling?


If I have a tube phono preamp with 6J2’s from the factory what would I try if I wanted to roll them to something better? A better brand 6J2? If so, which? 

Another tube all together? If so, which? 
128x128dougeyjones
@dougeyjones   Just curious, which phono pre do you have that utilizes those tubes?
I generally use a NAD PP-3, but was considering picking up the well liked ChiFi Fosi tube phono pre just for fun to see what it sounds like. Not a big investment.

Fosi Audio Phono Preamp for Turntable Preamplifier MM Phonograph Preamplifier with Gain Gear Mini Stereo Audio Hi-Fi Pre-Amplifier for Record Player with DC 12V Power Supply Box X2 https://www.amazon.com/dp/B07XNTHHBP/ref=cm_sw_r_cp_api_i_or.oFbHY1TEY3
not knowing your budget, I hopped about on eBay, see what's interesting,

this unit is very simple appearance, but read the notes, very versatile for MM, MC HO, MC LO
you would be set for most future cartridge choices

https://www.ebay.com/itm/Jolida-JD9-II-Tube-MM-MC-Phono-Preamplifier-JD-9-Mk-2/333673949970?hash=item4db0846b12:g:SUAAAOSwXvZfJz7V

Jolida site

https://www.jolida.com/product/jd-9-ii-phono-preamp

different tubes I know, just think they are worth considering, if only to spark questions