I experiment with different pre's in every one of my amps until I get the response I'm looking for. I have a different set up in each amp. I haven't found one preamp or power tube that is my favorite. Right now, I'm experimenting with the Tube Store's Premium 12AX7-ECC83. They work quite well in my Blues Juniors, Pro Junior, and Blues Deluxe. JJ's are a nice lively preamp tube, and affordable. I like them better than the R.I. Tungsols and Mullards in the aforementioned amps. I also use Sovtek 12AX7-LPS when I want to brighten up an amp, but they can get microphonic in certain amps. The LPS pre's seem to work nicely with the Winged C (real Svetlana) power tubes when used in the Deville Series amps from the 90's.