EL 34s for Cayin A 50T Integrated Amp


I am thinking of changing out the stock tubes (The EL34s) in my Cayin tube amplifier, but don't know what brands to look for. I mainly play rock and I am looking to improve my base and possibly the level of detail as well. Does anybody have any suggestions?

Thanks for your help!
marntz4me
I second the SED =C= that Olimpico mentioned. Well balanced, "real" sounding, textured tube, with very good dynamics.
I saw a set of 4 Sveltlanas but they are not the "Winged C" that people are talking about. Are they good as well or is the difference night and day when compared to the "Winged C's? Also, the electro harmonix that you are referring to replaces the small tubes in the Cayin?