Tube rolling my preamp with 6922EH


I'm planning on testing the Electro-Harmonix 6922EH's in my preamp, from the stock Sovtek's. Anyone have experience with these or the 6922EHG with Gold Pins? How much improvement can you get with the gold pins?
parapatton
My preamp is the Bob Carver Sunfire vacuum tube control center which is running 3 stock sovtek 6922's. I know better tubes will make an improvement and am trying to find some good tube alternatives.
In what way would you like to improve the sound from your pre-amp? You need a fix on that otherwise you will just be fling as blind as the recommendations that you will receive.

'Improvement' is too vague, especially when what most folks are actually looking for is a tonal 'difference'. The few that don't are usually looking for the same tonal balance but want greater clarity.

Tell us what you are looking for and if it is obtainable I'm sure you will get some sound recommendations.
Like to achieve a warmer, darker and transparent sound with a focused bass and less highs.
"Warmer" and "darker" are colorations and exactly the opposite of "transparent". If you want "warmer" sound and less highs, a pair of NOS Mullard, Ediswan or Brimar tubes(British manufacture/coloration), ie: (http://www.upscaleaudio.com/product.asp?itemid=282&catid=42) will provide that without a sacrifice in imaging or soundstage.
I should have mentioned: With regards to the "focused bass" you're seeking- That's usually more a function of the amp/room/speaker/cable/interconnect combo. Of course the preamp plays a role as well, but the pre and tubes can provide as accurate a signal as possible, yet the bass end up sloppy via a lack of synergy elsewhere.